A theoretical study had been carried out on the effect of radiation on the
electrical properties of silicon power diodes. Computer program
"PDRAD2015" was developed to solve the diode equations and to
introduce the operating conditions and radiation effects upon its
parameters. Temperature increase interrupts the electrical properties of the
diode in the direction of drop voltage decrease across the p-n junction. The
model was analyzed under the influence of different radiation type (gammarays,
neutrons, protons and electrons) with various dose levels and
energies. The carrier’s diffusion lengths were seriously affected leading
to a large increase in the forward voltage. These effects were found to be
function of radiation type, fluence and energy.
Partially filled electrode for DMF devicesWaleed Salman
This document describes research into partially filled electrodes for digital microfluidic devices. The researchers conducted simulations and experiments to evaluate how reducing the filled area of electrodes affects actuation forces on droplets. The simulations showed that actuation force decreases linearly as electrode fill percentage decreases. However, forces were independent of the vertical location of removed electrode areas. Experiments confirmed that partially filled electrodes can still achieve droplet actuation speeds sufficient for many applications, with frequencies over 10 electrodes per second achieved at 40% fill area. Partially filled electrodes also allow integration of additional on-chip elements and transmission microscopy imaging of droplets.
This study examines how liquid electrical properties (conductivity and permittivity) and the frequency of an applied voltage affect electrodynamic forces on droplets in digital microfluidic devices. The study finds that forces increase with conductivity up to 10-3 S/m and decrease significantly above a threshold frequency that depends on conductivity. Numerical simulations and experiments show that low conductivity liquids are best actuated at low frequencies while high conductivity liquids can be manipulated at higher frequencies without reducing forces. These results help optimize voltage and frequency for generating the strongest actuating forces on droplets.
This paper presents a highly efficient power transfer system based on a co-design of a class-E power amplifier (PA) and a pair of inductively coupled Helical coils for through-metal-wall power transfer. Power is transferred wirelessly through a 3.1-mm thick aluminum barrier without any physical penetration and contact. Measurement results show that the class-E PA achieves a peak power gain of 25.2 dB and a maximum collector efficiency of 57.3%, all at 200 Hz. The proposed system obtains a maximum power transfer efficiency of 9% and it can deliver 5 W power to the receiver side through the aluminum barrier.
Photovoltaics: Fundamental Concepts and novel systems
Energy levels -bands
Doping of semiconductors
Energy band alignments between different phases
Space charge layers
p-n junctions, Schottky barriers
p-n cells, Si cells, thin film cells
Schottky cells (solid and liquid junction)
p-i-n cells
Fundamental limits of photovoltaic cells
How to overcome/ bypass these limits
New generation cells (brief survey)
PV stability, efficiencies and economics
https://www.linkedin.com/in/preeti-choudhary-266414182/
https://www.instagram.com/chaudharypreeti1997/
https://www.facebook.com/profile.php?id=100013419194533
https://twitter.com/preetic27018281
Please like, share, comment and follow.
stay connected
If any query then contact:
chaudharypreeti1997@gmail.com
Thanking-You
Preeti Choudhary
Radial dynamics of electrons in two-section linear acceleratorIJECEIAES
This article discusses possibility of harness wiring with the use of focusing system of high frequency eigenfields of accelerating resonators in standing wave linear accelerators on the basis of biperiodic slowing systems. The scopes of business activities and specificity of existing engineering processes applied in industry, especially in chemistry and metallurgy, require for special measures on environmental protection. At present electron linear accelerators operating in pulse mode are used for application purposes. Such accelerators can be characterized by sufficient beam power for efficient industrial use and for environmental protection. The results of numerical analysis of electron dynamics in two-section accelerator upon various initial conditions are presented. The obtained results are applied for development of actual accelerator, calculated and experimental data are given. The performed experimental study confirmed possibility of development of standing wave linear accelerator without external magnetic focusing system with output beam diameter of not higher than . The results of calculations of beam dynamics are experimentally verified.
Accelerators and Applications- Summer Training in Physics 16Kamalakkannan K
Particle accelerators are used to study nuclear structure by providing high energies needed to see subatomic details. They work by using electric fields to accelerate charged particles, gaining kinetic energy. Accelerators are essential for understanding materials through techniques like Rutherford backscattering spectroscopy (RBS) which uses ion beams and detection of backscattered ions to determine thickness, composition, and depth profiling of materials. Key applications of accelerators include ion implantation to dope materials, cancer treatment, materials characterization using techniques like RBS, and transmuting nuclear waste.
This document discusses swift heavy ion irradiation and its effects on materials. It notes that energetic ion beams can be used to modify the surface and bulk structure of materials, altering properties like electrical, optical, and mechanical characteristics. Heavy ion irradiation above 2MeV interacts primarily through electronic stopping, depositing energy into the electron cloud near the ion's path. This can create defects like dislocations, amorphous regions, and change refractive index, enabling applications like waveguide formation. The degree of materials modification depends on factors like the ion species, energy, and fluence.
Measurements Of Dielectric Constant Of Solid Material (Leather Belt) At X-Ba...IJMER
This article discusses the experimental measurement technique for dielectric constant (i.e.
permittivity ) of leather belt at X-band. This measurement play selection of dielectric constant for
antenna substrate. This leather can be used as flexible substrate of wearable microstrip antenna. This
measurement system consist of solid state klystron power supply, isolator, VSWR meter, frequency meter,
solid dielectric cell (XC-501). This data may be interested in flexibility wearable microstrip antenna
studies and design.
Partially filled electrode for DMF devicesWaleed Salman
This document describes research into partially filled electrodes for digital microfluidic devices. The researchers conducted simulations and experiments to evaluate how reducing the filled area of electrodes affects actuation forces on droplets. The simulations showed that actuation force decreases linearly as electrode fill percentage decreases. However, forces were independent of the vertical location of removed electrode areas. Experiments confirmed that partially filled electrodes can still achieve droplet actuation speeds sufficient for many applications, with frequencies over 10 electrodes per second achieved at 40% fill area. Partially filled electrodes also allow integration of additional on-chip elements and transmission microscopy imaging of droplets.
This study examines how liquid electrical properties (conductivity and permittivity) and the frequency of an applied voltage affect electrodynamic forces on droplets in digital microfluidic devices. The study finds that forces increase with conductivity up to 10-3 S/m and decrease significantly above a threshold frequency that depends on conductivity. Numerical simulations and experiments show that low conductivity liquids are best actuated at low frequencies while high conductivity liquids can be manipulated at higher frequencies without reducing forces. These results help optimize voltage and frequency for generating the strongest actuating forces on droplets.
This paper presents a highly efficient power transfer system based on a co-design of a class-E power amplifier (PA) and a pair of inductively coupled Helical coils for through-metal-wall power transfer. Power is transferred wirelessly through a 3.1-mm thick aluminum barrier without any physical penetration and contact. Measurement results show that the class-E PA achieves a peak power gain of 25.2 dB and a maximum collector efficiency of 57.3%, all at 200 Hz. The proposed system obtains a maximum power transfer efficiency of 9% and it can deliver 5 W power to the receiver side through the aluminum barrier.
Photovoltaics: Fundamental Concepts and novel systems
Energy levels -bands
Doping of semiconductors
Energy band alignments between different phases
Space charge layers
p-n junctions, Schottky barriers
p-n cells, Si cells, thin film cells
Schottky cells (solid and liquid junction)
p-i-n cells
Fundamental limits of photovoltaic cells
How to overcome/ bypass these limits
New generation cells (brief survey)
PV stability, efficiencies and economics
https://www.linkedin.com/in/preeti-choudhary-266414182/
https://www.instagram.com/chaudharypreeti1997/
https://www.facebook.com/profile.php?id=100013419194533
https://twitter.com/preetic27018281
Please like, share, comment and follow.
stay connected
If any query then contact:
chaudharypreeti1997@gmail.com
Thanking-You
Preeti Choudhary
Radial dynamics of electrons in two-section linear acceleratorIJECEIAES
This article discusses possibility of harness wiring with the use of focusing system of high frequency eigenfields of accelerating resonators in standing wave linear accelerators on the basis of biperiodic slowing systems. The scopes of business activities and specificity of existing engineering processes applied in industry, especially in chemistry and metallurgy, require for special measures on environmental protection. At present electron linear accelerators operating in pulse mode are used for application purposes. Such accelerators can be characterized by sufficient beam power for efficient industrial use and for environmental protection. The results of numerical analysis of electron dynamics in two-section accelerator upon various initial conditions are presented. The obtained results are applied for development of actual accelerator, calculated and experimental data are given. The performed experimental study confirmed possibility of development of standing wave linear accelerator without external magnetic focusing system with output beam diameter of not higher than . The results of calculations of beam dynamics are experimentally verified.
Accelerators and Applications- Summer Training in Physics 16Kamalakkannan K
Particle accelerators are used to study nuclear structure by providing high energies needed to see subatomic details. They work by using electric fields to accelerate charged particles, gaining kinetic energy. Accelerators are essential for understanding materials through techniques like Rutherford backscattering spectroscopy (RBS) which uses ion beams and detection of backscattered ions to determine thickness, composition, and depth profiling of materials. Key applications of accelerators include ion implantation to dope materials, cancer treatment, materials characterization using techniques like RBS, and transmuting nuclear waste.
This document discusses swift heavy ion irradiation and its effects on materials. It notes that energetic ion beams can be used to modify the surface and bulk structure of materials, altering properties like electrical, optical, and mechanical characteristics. Heavy ion irradiation above 2MeV interacts primarily through electronic stopping, depositing energy into the electron cloud near the ion's path. This can create defects like dislocations, amorphous regions, and change refractive index, enabling applications like waveguide formation. The degree of materials modification depends on factors like the ion species, energy, and fluence.
Measurements Of Dielectric Constant Of Solid Material (Leather Belt) At X-Ba...IJMER
This article discusses the experimental measurement technique for dielectric constant (i.e.
permittivity ) of leather belt at X-band. This measurement play selection of dielectric constant for
antenna substrate. This leather can be used as flexible substrate of wearable microstrip antenna. This
measurement system consist of solid state klystron power supply, isolator, VSWR meter, frequency meter,
solid dielectric cell (XC-501). This data may be interested in flexibility wearable microstrip antenna
studies and design.
Impact of gamma-ray irradiation on dynamic characteristics of Si and SiC powe...IJECEIAES
Power electronic devices in spacecraft and military applications requires high radiation tolerant. The semiconductor devices face the issue of device degradation due to their sensitivity to radiation. Power MOSFET is one of the primary components of these power electronic devices because of its capabilities of fast switching speed and low power consumption. These abilities are challenged by ionizing radiation which damages the devices by inducing charge built-up in the sensitive oxide layer of power MOSFET. Radiations degrade the oxides in a power MOSFET through Total Ionization Dose effect mechanism that creates defects by generation of excessive electron–hole pairs causing electrical characteristics shifts. This study investigates the impact of gamma ray irradiation on dynamic characteristics of silicon and silicon carbide power MOSFET. The switching speed is limit at the higher doses due to the increase capacitance in power MOSFETs. Thus, the power circuit may operate improper due to the switching speed has changed by increasing or decreasing capacitances in power MOSFETs. These defects are obtained due to the penetration of Cobalt60 gamma ray dose level from 50krad to 600krad. The irradiated devices were evaluated through its shifts in the capacitance-voltage characteristics, results were analyzed and plotted for the both silicon and silicon carbide power MOSFET.
This document provides information about an online presentation on the electrical resistivity method in applied geophysics and engineering geology. It includes details about the date, time, presenter, and link to join the Zoom meeting. The bulk of the document then discusses the background and principles of the electrical resistivity method, including different electrode configurations, modes of deployment like vertical electrical sounding and constant separation traversing, and factors that influence electrode selection. Tables provide data on resistivities of common rocks and minerals and geometric factors for different electrode arrays.
This document provides information about swift heavy ion irradiation and its role in materials science. It discusses the 15UD Pelletron facility at Inter University Accelerator Centre in New Delhi, India, which can produce beams of various heavy ions up to 15MV. Energetic heavy ions can modify materials through electronic and nuclear energy loss. Defect formation, amorphization, and phase transformations can occur in materials due to swift heavy ion irradiation. The document focuses on using this technique to study and modify properties of nonlinear optical materials for applications in photonics and optoelectronics.
The Performance of a Cylindrical Microstrip Printed Antenna for TM10 Mode as...ijngnjournal
A temperature is one of the parameters that have a great effect on the performance of microstrip antennas for TM10 mode at 2.4 GHz frequency range. The effect of temperature on a resonance frequency, input impedance, voltage standing wave ratio, and return loss on the performance of a cylindrical microstrip printed antenna is studied in this paper. The effect of temperature on electric and magnetic fields are also studied. Three different substrate materials RT/duroid-5880 PTFE, K-6098 Teflon/Glass, and Epsilam-10 ceramic-filled Teflon are used for verifying the new model.
3D resistivity imaging uses multi-electrode systems to allow three-dimensional reconstruction of subsurface structures. It has advantages over 2D resistivity imaging in detecting complex underground features. The document discusses 3D resistivity imaging techniques, including:
- Inversion of large data sets using faster computers to model subsurface resistivity in small blocks
- Common electrode arrays like pole-pole, pole-dipole, and dipole-dipole
- Sensitivity patterns that make some arrays better for detecting off-axis underground objects
- Procedures for field measurement and combining multiple 2D data sets for 3D inversion modeling
2 d electrical resistivity tomography (ert) survey using the multi electrode ...Alexander Decker
1) 2D electrical resistivity tomography (ERT) surveys were conducted along six radial profiles at the Bosumtwi impact crater in Ghana using a modified multi-electrode gradient array.
2) The cable take-outs of the resistivity imaging system were modified from 2m to 5m spacing, allowing investigation of the subsurface to depths of around 75m.
3) The ERT models identified three subsurface formations - low resistivity lake sediments, moderately resistive impact breccias, and highly resistive basement metamorphic rocks.
This document reports on a project to measure the dielectric properties of materials at microwave frequencies. It discusses key concepts such as dielectric constant, permittivity, permeability, Maxwell's equations and how they relate to a material's ability to store and transmit electromagnetic energy. It describes measurement techniques using resonant cavities and waveguides to characterize a material's dielectric constant and loss factor. Sample preparation and ensuring uniform temperature and moisture conditions are important. Both resonant cavity and transmission line methods are covered, with cavity methods noted as providing higher accuracy for loss measurements.
Electromagnetic studies on nano sized magnesium ferriteIAEME Publication
The document summarizes research on the electromagnetic properties of nano-sized magnesium ferrite synthesized using microwave techniques. Key findings include:
1) Magnetic properties were measured using VSM which showed the material has a high coercivity of 785.12 Oe, classifying it as a hard magnetic material.
2) Dielectric measurements found the ac conductivity and dielectric constant decreased with increasing frequency. Both increased with temperature initially before decreasing.
3) The dielectric loss showed expected dispersion behavior, decreasing with frequency and generally increasing with temperature.
4) A high quality factor of 150 was obtained, higher than for bulk ferrites, indicating potential applications in microwave devices.
To perform geological exploration by the geophysical method of electrical resistivity.
The objective of this research is to evaluate the water potential of the study area by investigating the shallow subsurface aquifer material properties and moisture distribution using 2D ERT techniques. During the shallow tube well design and development in the study area, some patches of land does have good potential and some does not, which motivated to understand the aquifer properties, aquifer material, and response. Hence the 2D ERT was carried out, oriented around the pond in the center and five ERT profiles.
SINGLE ELECTRON TRANSISTOR: APPLICATIONS & PROBLEMSVLSICS Design
1) Single electron transistors (SETs) function by controlling the transfer of individual electrons between small conducting islands. They exhibit quantum properties like Coulomb blockade and oscillations that enable applications.
2) SETs consist of a small conducting island coupled to source and drain leads by tunnel junctions. Current flows when the applied voltage exceeds the threshold voltage needed to overcome Coulomb blockade.
3) Potential SET applications include ultrasensitive electrometry, quantum dot spectroscopy, standards for current and temperature, and detection of terahertz radiation. Challenges include fabricating small enough islands and addressing issues like background charge.
This document discusses electrical conductivity in various materials. It begins by explaining that metals are good conductors due to their large number of free electrons. Semiconductors have lower conductivity than metals due to their lower concentration of free charge carriers. Conductivity in nonmetals like ionic crystals and glasses depends on mobile charges like electrons and ions. The document then discusses how conductivity varies with temperature in nonmetals. It also covers the skin effect in conductors at high frequencies and conductivity considerations in thin metal films. The document concludes by discussing copper interconnects in microelectronics.
Dielectrics are materials that have permanent electric dipole moments. All dielectrics are electrical insulators and are mainly used to store electrical energy by utilizing bound electric charges and dipoles within their molecular structure. Important properties of dielectrics include their electric intensity or field strength, electric flux density, dielectric parameters such as dielectric constant and electric dipole moment, and polarization processes including electronic, ionic, and orientation polarization. Dielectrics are characterized by their complex permittivity, which relates to their ability to transmit electric fields and is dependent on factors like frequency, temperature, and humidity that can influence dielectric losses.
Electrical resistivity and electromagnetic method for detection of water bear...shubham shukla
1) The document discusses electrical resistivity and electromagnetic methods for detecting groundwater zones. It describes how each method works, including the instruments used, field techniques, and types of surveys conducted.
2) Results of surveys done in India show that both methods can identify potential aquifers at depths of 10-100 meters, though electrical resistivity has limitations like equivalence and anisotropy effects. Electromagnetic has issues with noise sensitivity.
3) Both methods have advantages and limitations depending on the geological conditions and budget. The comparative study provides guidance on which method to use in different situations for groundwater exploration.
This document discusses the design and construction of a DC generator. It begins with introductions to power engineering and electric generators. It then discusses permanent magnet generators and their advantages over induction motors. The objectives are to build a DC generator capable of lighting 10 LEDs. Materials used include a neodymium permanent magnet and copper magnetic wire wound into a coil. The results and discussion section outlines factors that determine generator efficiency such as magnet type and strength, magnetic gap, winding resistance, heat, windage, and load characteristics. The goal is to determine if the design is on the right track to meet the objectives.
Exploration Geology- Radioactive method of explorationsruthy sajeev
This document provides an overview of radioactive dating methods and radioactive detectors. It defines key terms like atoms, isotopes, alpha particles, beta particles, and gamma radiation. It describes the three main types of radioactive decay and how decay rates are used to date materials. Two common radioactive detectors, the Geiger-Muller counter and scintillation counter, are summarized. The GM counter detects beta radiation close up while the scintillation counter is more efficient for gamma rays and can be used from a distance or while mobile.
EIS is a powerful method of analyzing the complex electrical resistance of a system ( is sensitive
to surface phenomena and changes of bulk properties) It can be used to determine semi-quantitative parameters of electrochemical processes occurring
at electrode surfaces
This presentation discusses electrical resistivity methods for geophysical surveying. It describes how resistivity utilizes differences in electric potential to image the subsurface. Key concepts covered include Ohm's law, electrode configurations like Wenner and Schlumberger arrays, methods like vertical electrical sounding and electric profiling, and instrumentation used including current sources, resistivity meters, and electrode types. Applications mentioned are groundwater detection, mineral exploration, and waste exploration.
This document proposes a system for wireless power transfer to electric vehicles using magnetic resonant couplings. It presents experimental results on helical antennas that could be installed on electric vehicles. The experiments show that:
1) Resonant frequencies of the transmitting and receiving antennas change depending on the air gap between them, but maximum efficiency remains high even for large air gaps.
2) Efficiency remains around 95-97% for air gaps up to 200mm and remains high even when coupling coefficients are weak at large air gaps.
3) Efficiency remains constant, around 95-96%, for varying power levels from -15dBm to 100W, showing that efficiency does not depend on power as predicted by equivalent circuit models.
Elastic moduli measurement of solid using ultrasonic techniqueAbu Sufyan Malik
Ultrasonic Testing is used for measuring characteristics of a material i.e. Elastic Modulus, Grain Size Measurement, Material Characterization and Velocity of Waves develop in a Waveguide. We used ‘Echo-Pulse Transducer’ to develop the guided wave in the waveguide of which we used as specimen(Cu). The values obtained experimentally and conventionally are explained in detail and compared in the respective slides.
Temperature, acceptor concentration and donor concentration dependency of ele...IJAMSE Journal
This document discusses the calculation of low-field electron mobility in bulk GaN and GaP semiconductors. It examines the dependency of mobility on temperature, acceptor concentration, and donor concentration. Five scattering mechanisms are considered: ionized impurity scattering, neutral impurity scattering, acoustic deformation potential scattering, piezoelectric scattering, and optical deformation potential scattering. Graphs show how the total electronic mobility decreases with increasing temperature and is mostly independent of acceptor/donor concentration for both materials. The document provides equations and parameters used to model each scattering mechanism and calculate the total mobility.
This document summarizes molecular dynamics simulations of radiation damage in zirconia (ZrO2) at energies ranging from 0.1-0.5 MeV. The simulations find that while zirconia is highly resistant to amorphization, there is still a large number of point defects and small defect clusters created by the radiation. However, these defects are isolated from each other, resulting in dilute damage that does not disrupt the long-range crystalline structure. The simulations quantify the number of displacements and defects over time and find that electronic energy losses play an important role in the damage evolution. The findings have implications for using zirconia in nuclear waste storage by suggesting radiation can create many point defects even while
Initial irradiation studies of four types of silicon sensors for use in an ILC calorimeter found:
1) Sensors were irradiated with electrons of 3.5-10.6 GeV energy showering in tungsten, producing hadronic species similar to those in an electromagnetic calorimeter shower.
2) P-type and n-type sensors from different manufacturers were tested, receiving doses up to 220 MRad.
3) Depending on the sensor type, efficient charge collection was observed for doses as high as 220 MRad, indicating some sensor technologies may be suitable for use in the highly irradiated ILC calorimeter.
Impact of gamma-ray irradiation on dynamic characteristics of Si and SiC powe...IJECEIAES
Power electronic devices in spacecraft and military applications requires high radiation tolerant. The semiconductor devices face the issue of device degradation due to their sensitivity to radiation. Power MOSFET is one of the primary components of these power electronic devices because of its capabilities of fast switching speed and low power consumption. These abilities are challenged by ionizing radiation which damages the devices by inducing charge built-up in the sensitive oxide layer of power MOSFET. Radiations degrade the oxides in a power MOSFET through Total Ionization Dose effect mechanism that creates defects by generation of excessive electron–hole pairs causing electrical characteristics shifts. This study investigates the impact of gamma ray irradiation on dynamic characteristics of silicon and silicon carbide power MOSFET. The switching speed is limit at the higher doses due to the increase capacitance in power MOSFETs. Thus, the power circuit may operate improper due to the switching speed has changed by increasing or decreasing capacitances in power MOSFETs. These defects are obtained due to the penetration of Cobalt60 gamma ray dose level from 50krad to 600krad. The irradiated devices were evaluated through its shifts in the capacitance-voltage characteristics, results were analyzed and plotted for the both silicon and silicon carbide power MOSFET.
This document provides information about an online presentation on the electrical resistivity method in applied geophysics and engineering geology. It includes details about the date, time, presenter, and link to join the Zoom meeting. The bulk of the document then discusses the background and principles of the electrical resistivity method, including different electrode configurations, modes of deployment like vertical electrical sounding and constant separation traversing, and factors that influence electrode selection. Tables provide data on resistivities of common rocks and minerals and geometric factors for different electrode arrays.
This document provides information about swift heavy ion irradiation and its role in materials science. It discusses the 15UD Pelletron facility at Inter University Accelerator Centre in New Delhi, India, which can produce beams of various heavy ions up to 15MV. Energetic heavy ions can modify materials through electronic and nuclear energy loss. Defect formation, amorphization, and phase transformations can occur in materials due to swift heavy ion irradiation. The document focuses on using this technique to study and modify properties of nonlinear optical materials for applications in photonics and optoelectronics.
The Performance of a Cylindrical Microstrip Printed Antenna for TM10 Mode as...ijngnjournal
A temperature is one of the parameters that have a great effect on the performance of microstrip antennas for TM10 mode at 2.4 GHz frequency range. The effect of temperature on a resonance frequency, input impedance, voltage standing wave ratio, and return loss on the performance of a cylindrical microstrip printed antenna is studied in this paper. The effect of temperature on electric and magnetic fields are also studied. Three different substrate materials RT/duroid-5880 PTFE, K-6098 Teflon/Glass, and Epsilam-10 ceramic-filled Teflon are used for verifying the new model.
3D resistivity imaging uses multi-electrode systems to allow three-dimensional reconstruction of subsurface structures. It has advantages over 2D resistivity imaging in detecting complex underground features. The document discusses 3D resistivity imaging techniques, including:
- Inversion of large data sets using faster computers to model subsurface resistivity in small blocks
- Common electrode arrays like pole-pole, pole-dipole, and dipole-dipole
- Sensitivity patterns that make some arrays better for detecting off-axis underground objects
- Procedures for field measurement and combining multiple 2D data sets for 3D inversion modeling
2 d electrical resistivity tomography (ert) survey using the multi electrode ...Alexander Decker
1) 2D electrical resistivity tomography (ERT) surveys were conducted along six radial profiles at the Bosumtwi impact crater in Ghana using a modified multi-electrode gradient array.
2) The cable take-outs of the resistivity imaging system were modified from 2m to 5m spacing, allowing investigation of the subsurface to depths of around 75m.
3) The ERT models identified three subsurface formations - low resistivity lake sediments, moderately resistive impact breccias, and highly resistive basement metamorphic rocks.
This document reports on a project to measure the dielectric properties of materials at microwave frequencies. It discusses key concepts such as dielectric constant, permittivity, permeability, Maxwell's equations and how they relate to a material's ability to store and transmit electromagnetic energy. It describes measurement techniques using resonant cavities and waveguides to characterize a material's dielectric constant and loss factor. Sample preparation and ensuring uniform temperature and moisture conditions are important. Both resonant cavity and transmission line methods are covered, with cavity methods noted as providing higher accuracy for loss measurements.
Electromagnetic studies on nano sized magnesium ferriteIAEME Publication
The document summarizes research on the electromagnetic properties of nano-sized magnesium ferrite synthesized using microwave techniques. Key findings include:
1) Magnetic properties were measured using VSM which showed the material has a high coercivity of 785.12 Oe, classifying it as a hard magnetic material.
2) Dielectric measurements found the ac conductivity and dielectric constant decreased with increasing frequency. Both increased with temperature initially before decreasing.
3) The dielectric loss showed expected dispersion behavior, decreasing with frequency and generally increasing with temperature.
4) A high quality factor of 150 was obtained, higher than for bulk ferrites, indicating potential applications in microwave devices.
To perform geological exploration by the geophysical method of electrical resistivity.
The objective of this research is to evaluate the water potential of the study area by investigating the shallow subsurface aquifer material properties and moisture distribution using 2D ERT techniques. During the shallow tube well design and development in the study area, some patches of land does have good potential and some does not, which motivated to understand the aquifer properties, aquifer material, and response. Hence the 2D ERT was carried out, oriented around the pond in the center and five ERT profiles.
SINGLE ELECTRON TRANSISTOR: APPLICATIONS & PROBLEMSVLSICS Design
1) Single electron transistors (SETs) function by controlling the transfer of individual electrons between small conducting islands. They exhibit quantum properties like Coulomb blockade and oscillations that enable applications.
2) SETs consist of a small conducting island coupled to source and drain leads by tunnel junctions. Current flows when the applied voltage exceeds the threshold voltage needed to overcome Coulomb blockade.
3) Potential SET applications include ultrasensitive electrometry, quantum dot spectroscopy, standards for current and temperature, and detection of terahertz radiation. Challenges include fabricating small enough islands and addressing issues like background charge.
This document discusses electrical conductivity in various materials. It begins by explaining that metals are good conductors due to their large number of free electrons. Semiconductors have lower conductivity than metals due to their lower concentration of free charge carriers. Conductivity in nonmetals like ionic crystals and glasses depends on mobile charges like electrons and ions. The document then discusses how conductivity varies with temperature in nonmetals. It also covers the skin effect in conductors at high frequencies and conductivity considerations in thin metal films. The document concludes by discussing copper interconnects in microelectronics.
Dielectrics are materials that have permanent electric dipole moments. All dielectrics are electrical insulators and are mainly used to store electrical energy by utilizing bound electric charges and dipoles within their molecular structure. Important properties of dielectrics include their electric intensity or field strength, electric flux density, dielectric parameters such as dielectric constant and electric dipole moment, and polarization processes including electronic, ionic, and orientation polarization. Dielectrics are characterized by their complex permittivity, which relates to their ability to transmit electric fields and is dependent on factors like frequency, temperature, and humidity that can influence dielectric losses.
Electrical resistivity and electromagnetic method for detection of water bear...shubham shukla
1) The document discusses electrical resistivity and electromagnetic methods for detecting groundwater zones. It describes how each method works, including the instruments used, field techniques, and types of surveys conducted.
2) Results of surveys done in India show that both methods can identify potential aquifers at depths of 10-100 meters, though electrical resistivity has limitations like equivalence and anisotropy effects. Electromagnetic has issues with noise sensitivity.
3) Both methods have advantages and limitations depending on the geological conditions and budget. The comparative study provides guidance on which method to use in different situations for groundwater exploration.
This document discusses the design and construction of a DC generator. It begins with introductions to power engineering and electric generators. It then discusses permanent magnet generators and their advantages over induction motors. The objectives are to build a DC generator capable of lighting 10 LEDs. Materials used include a neodymium permanent magnet and copper magnetic wire wound into a coil. The results and discussion section outlines factors that determine generator efficiency such as magnet type and strength, magnetic gap, winding resistance, heat, windage, and load characteristics. The goal is to determine if the design is on the right track to meet the objectives.
Exploration Geology- Radioactive method of explorationsruthy sajeev
This document provides an overview of radioactive dating methods and radioactive detectors. It defines key terms like atoms, isotopes, alpha particles, beta particles, and gamma radiation. It describes the three main types of radioactive decay and how decay rates are used to date materials. Two common radioactive detectors, the Geiger-Muller counter and scintillation counter, are summarized. The GM counter detects beta radiation close up while the scintillation counter is more efficient for gamma rays and can be used from a distance or while mobile.
EIS is a powerful method of analyzing the complex electrical resistance of a system ( is sensitive
to surface phenomena and changes of bulk properties) It can be used to determine semi-quantitative parameters of electrochemical processes occurring
at electrode surfaces
This presentation discusses electrical resistivity methods for geophysical surveying. It describes how resistivity utilizes differences in electric potential to image the subsurface. Key concepts covered include Ohm's law, electrode configurations like Wenner and Schlumberger arrays, methods like vertical electrical sounding and electric profiling, and instrumentation used including current sources, resistivity meters, and electrode types. Applications mentioned are groundwater detection, mineral exploration, and waste exploration.
This document proposes a system for wireless power transfer to electric vehicles using magnetic resonant couplings. It presents experimental results on helical antennas that could be installed on electric vehicles. The experiments show that:
1) Resonant frequencies of the transmitting and receiving antennas change depending on the air gap between them, but maximum efficiency remains high even for large air gaps.
2) Efficiency remains around 95-97% for air gaps up to 200mm and remains high even when coupling coefficients are weak at large air gaps.
3) Efficiency remains constant, around 95-96%, for varying power levels from -15dBm to 100W, showing that efficiency does not depend on power as predicted by equivalent circuit models.
Elastic moduli measurement of solid using ultrasonic techniqueAbu Sufyan Malik
Ultrasonic Testing is used for measuring characteristics of a material i.e. Elastic Modulus, Grain Size Measurement, Material Characterization and Velocity of Waves develop in a Waveguide. We used ‘Echo-Pulse Transducer’ to develop the guided wave in the waveguide of which we used as specimen(Cu). The values obtained experimentally and conventionally are explained in detail and compared in the respective slides.
Temperature, acceptor concentration and donor concentration dependency of ele...IJAMSE Journal
This document discusses the calculation of low-field electron mobility in bulk GaN and GaP semiconductors. It examines the dependency of mobility on temperature, acceptor concentration, and donor concentration. Five scattering mechanisms are considered: ionized impurity scattering, neutral impurity scattering, acoustic deformation potential scattering, piezoelectric scattering, and optical deformation potential scattering. Graphs show how the total electronic mobility decreases with increasing temperature and is mostly independent of acceptor/donor concentration for both materials. The document provides equations and parameters used to model each scattering mechanism and calculate the total mobility.
This document summarizes molecular dynamics simulations of radiation damage in zirconia (ZrO2) at energies ranging from 0.1-0.5 MeV. The simulations find that while zirconia is highly resistant to amorphization, there is still a large number of point defects and small defect clusters created by the radiation. However, these defects are isolated from each other, resulting in dilute damage that does not disrupt the long-range crystalline structure. The simulations quantify the number of displacements and defects over time and find that electronic energy losses play an important role in the damage evolution. The findings have implications for using zirconia in nuclear waste storage by suggesting radiation can create many point defects even while
Initial irradiation studies of four types of silicon sensors for use in an ILC calorimeter found:
1) Sensors were irradiated with electrons of 3.5-10.6 GeV energy showering in tungsten, producing hadronic species similar to those in an electromagnetic calorimeter shower.
2) P-type and n-type sensors from different manufacturers were tested, receiving doses up to 220 MRad.
3) Depending on the sensor type, efficient charge collection was observed for doses as high as 220 MRad, indicating some sensor technologies may be suitable for use in the highly irradiated ILC calorimeter.
Some Aspects of Stress Distribution and Effect of Voids Having Different Gase...IOSR Journals
1) The document analyzes the stress distribution and effect of voids with different gases in MV power cables through finite element modeling. It studies the electric field and temperature distribution within cable insulation containing voids.
2) Cylindrical voids are found to have higher electric stress than spherical or elliptical voids. Among gases, oxygen consumption during partial discharge causes greater temperature rise and faster breakdown than nitrogen.
3) The analysis examines factors like void shape, position, and size that influence stress distribution and partial discharge inception voltage. Nearer and larger voids have lower inception voltages. Oxygen consumption leads to uniform erosion and higher temperatures, making its effect greater than other gases.
This study investigated the impact of a nickel interlayer on the electrical resistance of a tin-tin interface under fretting loading conditions. Two coating systems were tested: bronze-tin and bronze-nickel-tin. Using variable displacement amplitude testing, the transition amplitude from partial slip to gross slip was determined. Constant displacement amplitude tests then evaluated the influence of the nickel interlayer on electrical endurance. The results showed that the nickel interlayer did not influence endurance in gross slip but eliminated copper diffusion through the tin coating, preventing copper oxide formation and extending the domain of partial slip. This increased the reliability of the electrical contact.
Single Electron Transistor: Applications & Problems VLSICS Design
1) Single electron transistors (SETs) function by controlling the transfer of individual electrons between small conducting islands. SETs exhibit quantum properties like Coulomb blockade and oscillations that enable applications in electronics.
2) SETs consist of a small conducting island coupled to source and drain leads by tunnel junctions. Current flows when the applied voltage exceeds the threshold voltage needed to overcome Coulomb blockade.
3) Potential SET applications include ultrasensitive electrometry, quantum dot spectroscopy, standards for current and temperature, and detection of terahertz radiation. However, challenges remain for room temperature operation and linking SETs into larger circuits.
Effect of mesh grid structure in reducing hot carrier effect of nmos device s...ijcsa
This paper presents the critical effect of mesh grid that should be considered during process and device
simulation using modern TCAD tools in order to develop and optimize their accurate electrical
characteristics. Here, the computational modelling process of developing the NMOS device structure is
performed in Athena and Atlas. The effect of Mesh grid on net doping profile, n++, and LDD sheet
resistance that could link to unwanted “Hot Carrier Effect” were investigated by varying the device grid
resolution in both directions. It is found that y-grid give more profound effect in the doping concentration,
the junction depth formation and the value of threshold voltage during simulation. Optimized mesh grid is
obtained and tested for more accurate and faster simulation. Process parameter (such as oxide thicknesses
and Sheet resistance) as well as Device Parameter (such as linear gain “beta” and SPICE level 3 mobility
roll-off parameter “ Theta”) are extracted and investigated for further different applications.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
The document reports on a study of the AC and DC conductivity of three glycine family nonlinear optical (NLO) single crystals: Trisglycine Zinc Chloride (TGZC), Triglycine Acetate (TGAc), and Glycine Lithium Sulphate (GLS). The AC conductivity was measured from 50 Hz to 5 MHz and increased with temperature for all crystals. The activation energies calculated from the AC conductivity were 0.035 eV for TGZC, 0.075 eV for TGAc, and 0.10 eV for GLS. The DC conductivity also increased with temperature from 313 K to 423 K, and the activation energies calculated were 0.050 eV for TGZC, 0.060 eV
Resonant-tunneling-diode effect in Si-based double-barrier structure sputtere...IJRES Journal
This paper presents the resonant-tunneling-diode (RTD) effect in a SiO2/n-Si/SiO2/p-Si double-barrier structural thin films fabricated using radio frequency (RF) magnetron sputtering at room temperature (300 K). The implementation of a circuit prototype is first accomplished by modulating a Si-based RTD with a solar-cell bias voltage. The important electrical properties of the peak current density and peak-to-valley current ratio (PVCR) are 184 nA/cm2 and 1.67, respectively. The connection between the two RTDs in series is biased by a solar cell. The value of the switching transition time is 24.37 μs; oscillation occurs with an operating frequency of 41.6 KHz. In semiconductor applications, the developed RTD is characterized by stability, enduring environmentally elevated temperature and relative humidity.
This document discusses the performance analysis of a microstrip printed antenna conformed on a cylindrical body operating at a resonance frequency of 4.6 GHz for the TM01 mode. It begins with an introduction to microstrip antennas and the effects of curvature. It then presents mathematical models for the electric and magnetic fields, input impedance, return loss, and voltage standing wave ratio for a curved microstrip antenna. Results show the resonance frequency shifts 35 MHz as the radius of curvature changes from 6 mm to a flat antenna. Graphs also show the real and imaginary parts of input impedance vary with frequency for different radii of curvature.
IRJET- Dielectric Properties of Titanium Substituted Manganese -Zinc Ferr...IRJET Journal
1. The document describes a study on the dielectric properties of a new crystalline ceramic material called Titanium Substituted Manganese -Zinc Ferrite System Mn0.8+xZn0.2TixFe2-2xO4 with x=0.20.
2. The dielectric properties measured include dielectric constant, dielectric loss, conductivity, and impedance and how they vary with frequency and temperature.
3. The material was prepared using a solid state reaction method and its dielectric properties were analyzed and discussed in terms of applications in electronics.
A Study on Liquid Dielectric Breakdown in Micro-EDM Discharge - Cognitio paperSantosh Verma
The research work carried out in this paper, aims at
understanding the breakdown phenomenon of liquid dielectric by the low energy ultra-short pulsed electric discharge produced between tiny electrodes (~ 100µm diameter electrode) through experimental studies In literature not many studies are reported on liquid dielectric breakdown mechanism, and in micro-EDM no published literature discusses about this. Therefore, a detailed study on literature has been performed and preliminary
experiments have conducted on micro-EDM to understand the glow discharge and its breakdown phenomenon better, towards validation of scientific analogies for micro-EDM process conditions.
Silicon carbide schottky diodes forward and reverse current properties upon f...journalBEEI
This paper investigates on the reaction of 10 and 15MGy, 3MeV electron irradiation upon off-the-shelves (commercial) Silicon Carbide Schottky diodes from Infineon Technologies (model: IDH08SG60C) and STMicroelectronics (model: STPSC806). Such irradiation reduces the forward-bias current. The reduction is mainly due to the significant increase of the series resistance (i.e. Infineon: 1.45Ω at before irradiation → 121×103 Ω at 15MGy); STMicroelectronics: 1.44Ω at before irradiation → 2.1×109 Ω at 15MGy). This increase in series resistance gives 4.6 and 8.2 orders of magnitude reduction for the forward-bias current density of Infineon and STMicroelectronics respectively. It is also observed that the ideality factor and the saturation current of the diodes increases with increasing dose (i.e. ideality factor- Infineon: 1.01 at before irradiation → 1.05 at 15MGy; STMicroelectronics: 1.02 at before irradiation → 1.3 at 15MGy | saturation current- Infineon: 1.6×10-17A at before irradiation → 2.5×10-17A at 15MGy; STMicroelectronics: 2.4×10-15A at before irradiation → 8×10-15A at 15MGy). Reverse-bias leakage current density in model by Infineon increases by one order of magnitude after 15MGy irradiation, however, in model by STMicroelectronics decreases by one order of magnitude. Overall, for these particular samples studied, Infineon devices have shown to be better in quality and more radiation resistance toward electron irradiation in forward-bias operation while STMicroelectronics exhibit better characteristics in reverse-bias operation.
Quantitative Modeling and Simulation of Single-Electron TransistorIRJET Journal
This document discusses quantitative modeling and simulation of the single-electron transistor (SET) using MATLAB Simulink. The SET is a nano-scaled transistor that operates using quantum tunneling of single electrons. The document describes the basic theory of quantum tunneling and Coulomb blockade in SETs. It then discusses modeling the SET using a master equation approach and simulating its DC characteristics such as current oscillations. Parameters like junction capacitance, gate capacitance, and temperature are varied to analyze their effect on SET characteristics.
This document discusses the relevance of studying electromagnetics in modern society. It begins by discussing how electromagnetics was primarily motivated by military defense applications such as radar technology. It then describes how electromagnetics is now crucial for high-speed electronics, photonic integrated circuits, microcavity laser design, and controlling ultrashort optical pulses. Computational solutions of Maxwell's equations are essential for effectively designing technologies across these applications.
The document provides information about high voltage engineering. It discusses various topics related to over voltages in electrical power systems and dielectric breakdown.
Some key points include:
1) Corona critical disruptive voltage is the voltage at which conductors glow faintly violet due to corona effect, producing ozone and power loss.
2) Overhead transmission line protections include ground wires, ground rods, counterpoise wires and protective devices.
3) Dielectric breakdown depends on factors like gas pressure, gap distance, and insulation material properties as per Paschen's law and Townsend's coefficients.
4) High voltage generation techniques include impulse generators, trigatron gaps, and voltage multiplier circuits like C
Study of Radiation Interaction Mechanisms of Different Nuclear DetectorsIJAEMSJORNAL
In this paper, an attempt has been made to describe the radiation interaction mechanisms of nuclear detectors. There are lots of radioactive detectors available in the field of radiation detection and measurements instruments/systems such as Geguier Muller (GM) Tube, Scintillation Counter, High Purity Germanium (HPGe) and so on. Each of these detectors have different and distinct radiation interaction mechanisms and detecting principle for processing each type of radiation measurement (qualititative and quantitative).The interaction mechanisms of these detectors are governed by generation of ions (positive and negative) in case of GM tube; the photo-electric effect, Compton scattering and pair production for Scintillation detector and HPGe along with diode principle. The special feature of this diode is a constant current generator depending on the energy of the photon deposition in the detector. The characteristics of these interaction mechanisms have been presented along with intensity of measurements, efficiency and detector resolution (FWHM).
Pb2003.01 problems with the electrostatic discharge (esd) immunity test in el...ESDEMC Technology LLC
Electrostatic discharge (ESD) immunity test is one of the important electromagnetic compatibility (EMC) tests. The IEC standard IECdlOOO-4-2 is the widely used standard to test the ESD immunity for electronic equipment. Many amendments such as amendment 1 (1998), amendment 2 (2000) have been published since 1995, but there is still problems with the ESD immunity test even with the 200x version. More than six ESD generators of different bands are tested for different equipment. The results show that the failure voltages of different ESD generators are vary much from different bands for the same test equipment. This may lead to the results incomparable when test the ESD immunity test in the EMC. Further studies show that there is a good correlation between the failure voltage and the induced voltage.
Set and seu analysis of cntfet based designs in harsh environmentseSAT Publishing House
This document analyzes the performance and radiation robustness of designs using carbon nanotube field-effect transistors (CNTFETs) compared to designs using metal-oxide-semiconductor field-effect transistors (MOSFETs). Simulations show that CNTFET logic gate designs demonstrate on average 45% improved resilience to single event transients compared to MOSFET designs. CNTFET latches also show improved energy and delay metrics with higher robustness than MOSFET latches. In an interconnect crossbar analysis, a CNTFET implementation occupied 25% less area and consumed 4 times less energy than a MOSFET implementation while handling the same critical charge levels.
Similar to Modeling the Dependence of Power Diode on Temperature and Radiation (20)
Inter-Area Oscillation Damping using an STATCOM Based Hybrid Shunt Compensati...IJPEDS-IAES
FACTS devices are one of the latest technologies which have been used to
improve power system dynamic and stability during recent years. However,
widespread adoption of this technology has been hampered by high cost
and reliability concerns. In this paper an economical phase imbalanced shunt
reactive compensation concept has been introduced and its ability for power
system dynamic enhancement and inter-area oscillation damping are
investigated. A hybrid phase imbalanced scheme is a shunt capacitive
compensation scheme, where two phases are compensated by fixed shunt
capacitor (C) and the third phase is compensated by a Static Synchronous
Compensator (STATCOM) in shunt with a fixed capacitor (CC). The power
system dynamic stability enhancement would be achieved by adding
a conventional Wide Area Damping Controller (WADC) to the main control
loop of the single phase STATCOM. Two different control methodologies
are proposed: a non-optimized conventional damping controller
and a conventional damping controller with optomised parameters that are
added to the main control loop of the unbalanced compensator in order to
damp the inter area oscillations. The proposed arrangement would, certainly,
be economically attractive when compared with a full three-phase
STATCOM. The proposed scheme is prosperously applied in a 13-bus
six-machine test system and various case studies are conducted to
demonstrate its ability in damping inter-area oscillations and power system
dynamic enhancement.
Fuzzy Gain-Scheduling Proportional–Integral Control for Improving the Speed B...IJPEDS-IAES
In this article, we have set up a vector control law of induction machine
where we tried different type of speed controllers. Our control strategy is of
type Field Orientated Control (FOC). In this structure we designed a Fuzzy
Gain-Scheduling Proportional–Integral (Pi) controller to obtain best result
regarding the speed of induction machine. At the beginning we designed a Pi
controller with fixed parameters. We came up to these parameters by
identifying the transfer function of this controller to that of Broïda (second
order transfer function). Then we designed a fuzzy logic (FL) controller.
Based on simulation results, we highlight the performances of each
controller. To improve the speed behaviour of the induction machine, we
have designend a controller called “Fuzzy Gain-Scheduling Proportional–
Integral controller” (FGS-PI controller) which inherited the pros of the
aforementioned controllers. The simulation result of this controller will
strengthen its performances.
Advance Technology in Application of Four Leg Inverters to UPQCIJPEDS-IAES
This article presents a novel application of four leg inverter with
conventional Sinusoidal Pulse Width Modulation (SPWM) Scheme to
Unified Power Quality Conditioner (UPQC). The Power Quality problem
became burning issues since the starting of high voltage AC transmission
system. Hence, in this article it has been discussed to mitigate the PQ issues
in high voltage AC systems through a three phase Unified Power Quality
Conditioner (UPQC) under various conditions, such as harmonic mitigation
scheme, non linear loads, sag and swell conditions as well. Also, it proposes
to control harmoincs with various artificial intelligent techniques. Thus
application of these control technique such as Neural Networks (ANN)
Fuzzy Logic makes the system performance in par with the standards
and also compared with existing system. The simulation results based on
MATLAB/Simulink are discussed in detail to support the concept developed
in the paper.
Modified SVPWM Algorithm for 3-Level Inverter Fed DTC Induction Motor DriveIJPEDS-IAES
In this paper, a modified space vector pulse width modulation (MSVPWM)
algorithm is developed for 3-level inverter fed direct torque controlled
induction motor drive (DTC-IMD). MSVPWM algorithm simplifies
conventional space vector pulse width modulation (CSVPWM) algorithm for
multilevel inverter (MLI), whose complexity lies in sector/subsector/subsubsector
identification; which will commensurate with number of levels. In
the proposed algorithm sectors are identified as in two level inverter
and subsectors/sub-subsectors are identified by shifting the original reference
vector to sector 1 (S1). This is valid due to the fact that a three level space
vector plane is a composition of six two level space planes, and are
symmetrical with reference to six pivot states. Switching state/sequence
selection is also very important while dealing with SVPWM strategy for
MLI. In the proposed algorithm out of 27 available switching states apt
switching state is selected based on sector and subsector number, such that
voltage ripple is considerably less. To validate the proposed algorithm, it is
tested on a three level neutral point clamped (NPC) inverter fed DTC-IMD.
The performance of the MSVPWM algorithm is analyzed by comparing no
load stator current ripple of the three level DTC-IMD with two level
DTC-IMD. Significant reduction in steady state torque and flux ripple is
observed. Hence, reduced acoustic noise is a distinctive facet of the proposed
method.
Modelling of a 3-Phase Induction Motor under Open-Phase Fault Using Matlab/Si...IJPEDS-IAES
The d-q model of Induction Motors (IMs) has been effectively used as an
efficient method to analyze the performance of the induction machines. This
study presents a step by step Matlab/Simulink implementation
of a star-connected 3-phase IM under open-phase fault (faulty 3-phase IM)
using d-q model. The presented technique in this paper can be simply
implemented in one block and can be made available for control purposes.
The simulated results provide to show the behavior of the star-connected 3-phase IM under open-phase fault condition.
Performance Characteristics of Induction Motor with FielIJPEDS-IAES
With development of power electronics and control Theories, the AC motor
control becomes easier. So the AC motors are used instead of the DC motor
in the drive applications. With this development, a several methods of control
are invented. The field oriented control and direct torque control are from the
best methods to control the drive systems. This paper is compared between
the field oriented control and direct torque control to show the advantages
and disadvantages of these methods of controls. This study discussed the
effects of these methods of control on the total harmonic distortion of the
current and torque ripples. This occurs through study the performance
characteristics of the AC motor. The motor used in this study is an induction
motor. This study is simulated through the MATLAB program.
A Novel Modified Turn-on Angle Control Scheme for Torque- Ripple Reduction in...IJPEDS-IAES
In recent years, Switched Reluctance Motors (SRM) have been dramatically
considered with both researchers and industries. SRMs not only have a
simple and reliable structure, but also have low cost production process.
However, discrete torque production of SRM along with intensive magnetic
saturation in stator and rotor cores are the major drawbacks of utilizing in
variety of industrial applications and also causes the inappropriate torque
ripples. In this paper, a modified logical-rule-based Torque Sharing Function
(TSF) method is proposed considering turn-on angle control. The optimized
turn-on angle for conducting each phase is achieved by estimating the
inductance curve in the vicinity of unaligned position and based on an
analytical solution for each phase voltage equation. Simulation results on a
four-phase switched reluctance motor and comparison with the conventional
methods validates the effectiveness of the proposed method.
Modeling and Simulation of Induction Motor based on Finite Element AnalysisIJPEDS-IAES
This paper presents the development of a co-simulation platform of induction
motor (IM). For the simulation, a coupled model is introduced which
contains the control, the power electronics and also the induction machine.
Each of these components is simulated in different software environments.
So, this study provides an advanced modeling and simulation tools for IM
which integrate all the components into one common simulation platform
environment. In this work, the IM is created using Ansys-Maxwell based on
Finite Element Analysis (FEA), whereas the power electronic converter is
developed in Ansys-Simplorer and the control scheme is build in MATLABSimulink
environment. Such structure can be useful for accurate design
and allows coupling analysis for more realistic simulation. This platform is
exploited to analyze the system models with faults caused by failures of
different drive’s components. Here, two studies cases are presented: the first
is the effects of a faulty device of the PWM inverter, and the second case is
the influence of the short circuit of two stator phases. In order to study the
performance of the control drive of the IM under fault conditions,
a co-simulation of the global dynamic model has been proposed to analyze
the IM behavior and control drives. In this work, the co-simulation has been
performed; furthermore the simulation results of scalar control allowed
verifying the precision of the proposed FEM platform.
Comparative Performance Study for Closed Loop Operation of an Adjustable Spee...IJPEDS-IAES
In this paper an extensive comparative study is carried out between PI
and PID controlled closed loop model of an adjustable speed Permanent
Magnet Synchronous Motor (PMSM) drive. The incorporation of Sinusoidal
Pulse Width Modulation (SPWM) strategy establishes near sinusoidal
armature phase currents and comparatively less torque ripples without
sacrificing torque/weight ratio. In this closed loop model of PMSM drive, the
information about reference speed is provided to a speed controller, to ensure
that actual drive speed tracks the reference speed with ideally zero steady
state speed error. The entire model of PMSM closed loop drive is divided
into two loops, inner loop current and outer loop speed. By taking the
different combinations of two classical controllers (PI & PID) related with
two loop control structure, different approximations are carried out. Hence a
typical comparative study is introduced to familiar with the different
performance indices of the system corresponding to time domain and
frequency domain specifications. Therefore overall performance of closed
loop PMSM drive is tested and effectiveness of controllers will be
determined for different combinations.
Novel Discrete Components Based Speed Controller for Induction MotorIJPEDS-IAES
This paper presents an electronic design based on general purpose discrete
components for speed control of a single phase induction motor drive. The
MOSFETs inverter switching is controlled using Sampled Sinusoidal Pulse
Width Modulation (SPWM) techniques with V/F method based on Voltage
Controlled Oscillator (VCO). The load power is also controlled by a novel
design to produce a suitable SPWM pulse. The proposed electronic system
has ability to control the output frequency with flexible setting of lower limit
to less than 1 Hz and to higher frequency limits to 55 Hz. Moreover, the
proposed controller able to control the value of load voltage to frequency
ratio, which plays a major parameter in the function of IM speed control.
Furthermore, the designed system is characterized by easy manufacturing
and maintenance, high speed response, low cost, and does not need to
program steps as compared to other systems based on Microcontroller
and digital signal processor (DSP) units. The complete proposed electronic
design is made by the software of NI Multisim version 11.0 and all the
internal sub-designs are shown in this paper. Simulation results show the
effectiveness of electronic design for a promising of a high performance IM
PWM drive.
Sensorless Control of a Fault Tolerant PMSM Drives in Case of Single-Phase Op...IJPEDS-IAES
This paper introduces a sensorless-speed-controlled PMSM motor fed by a
four-leg inverter in case of a single phase open circuit fault regardless in
which phase is the fault. To minimize the system performance degradation
due to a single phase open circuit fault, a fault tolerant control strategy that
includes taking appropriate actions to control the two remaining healthy
currents is used in addition to use the fourth leg of the inverter. Tracking the
saliency is done through measuring the dynamic current responses of the
healthy phases of the PMSM motor due the IGBT switching actions using the
fundamental PWM method without introducing any modification to the
operation of the fourth leg of the inverter. Simulation results are provided to
verify the effectiveness of the proposed strategy for sensorless controlling of
a PMSM motor driven by a fault-tolerant four-phase inverter over a wide
speed ranges under the case of a single phase open circuit.
Improved Stator Flux Estimation for Direct Torque Control of Induction Motor ...IJPEDS-IAES
Stator flux estimation using voltage model is basically the integration of the
induced stator back electromotive force (emf) signal. In practical
implementation the pure integration is replaced by a low pass filter to avoid
the DC drift and saturation problems at the integrator output because of the
initial condition error and the inevitable DC components in the back emf
signal. However, the low pass filter introduces errors in the estimated stator
flux which are significant at frequencies near or lower than the cutoff
frequency. Also the DC components in the back emf signal are amplified at
the low pass filter output by a factor equals to . Therefore, different
integration algorithms have been proposed to improve the stator flux
estimation at steady state and transient conditions. In this paper a new
algorithm for stator flux estimation is proposed for direct torque control
(DTC) of induction motor drives. The proposed algorithm is composed of a
second order high pass filter and an integrator which can effectively
eliminates the effect of the error initial condition and the DC components.
The amplitude and phase errors compensation algorithm is selected such that
the steady state frequency response amplitude and phase angle are equivalent
to that of the pure integrator and the multiplication and division by stator
frequency are avoided. Also the cutoff frequency selection is improved; even
small value can filter out the DC components in the back emf signal. The
simulation results show the improved performance of the induction motor
direct torque control drive with the proposed stator flux estimation algorithm.
The simulation results are verified by the experimental results.
Minimization of Starting Energy Loss of Three Phase Induction Motors Based on...IJPEDS-IAES
The purpose of this paper is to minimize energy losses consumed by three
phase induction motors during starting with wide range of load torque from
no load to full load. This will limit the temperature rise and allows for more
numbers of starting during a definite time. Starting energy losses
minimization is achieved by controlling the rate of increasing voltage
and frequency to start induction motor under certain load torque within a
definite starting time. Optimal voltage and frequency are obtained by particle
swarm optimization (PSO) tool according to load torque. Then, outputs of the
PSO are used to design a neuro-fuzzy controller to control the output voltage
and frequency of the inverter during starting for each load torque. The
starting characteristics using proposed method are compared to that of direct
on line and V/F methods. A complete model of the system is developed using
SIMULINK/MATLAB.
Hardware Implementation of Solar Based Boost to SEPIC Converter Fed Nine Leve...IJPEDS-IAES
Multi level inverters are widely used in high power applications because of
low harmonic distortion. This paper deals with the simulation
and implementation of PV based boost to SEPIC converter with multilevel
inverter. The output of PV system is stepped up using boost to sepic
converter and it is converted into AC using a multilevel inverter.
The simulation and experimental results with the R load is presented in this
paper. The FFT analysis is done and the THD values are compared. Boost to
SEPIC converter is proposed to step up the voltage to the required value. The
experimental results are compared with the simulation results. The results
indicate that nine level inverter system has better performance than seven
level inverter system.
Transformer Less Voltage Quadrupler Based DC-DC Converter with Coupled Induct...IJPEDS-IAES
In this paper a voltage quadrupler dc-dc converter with coupled inductor
and π filter is presented. The use of the coupled inductor reduces the high
leakage inductance which is present in a transformer enabled converter.
The output ripples in the converter is reduced by providing a π filter.
The interleaved voltage quadrupler is used in this system in order to boost the
output voltage. The voltage multiplier improves the output voltage gain.
The main advantage of this system is more voltage gain when compared with
the transformer eneabled circuit and the overall efficiency of the system is
improved. The circuit is simple to control. As a final point of this research,
the simulation and the hardware investigational results are presented to
demonstrate the effectiveness of this proposed converter.
IRAMY Inverter Control for Solar Electric VehicleIJPEDS-IAES
Solar Electric Vehicles (SEV) are considered the future vehicles to solve the issues of air pollution, global warming, and the rapid decreases of the petroleum resources facing the current transportation technology. However, SEV are still facing important technical obstacles to overcome. They include batteries energy storage capacity, charging times, efficiency of the solar panels and electrical propulsion systems. Solving any of those problems and electric vehicles will compete-complement the internal combustion engines vehicles. In the present work, we propose an electrical propulsion system based on three phase induction motor in order to obtain the desired speed and torque with less power loss. Because of the need to lightweight nature, small volume, low cost, less maintenance and high efficiency system, a three phase squirrel cage induction motor (IM) is selected in the electrical propulsion system. The IM is fed from three phase inverter operated by a constant V/F control method and Space Vector Pulse Width Modulation (SVPWM) algorithm. The proposed control strategy has been implemented on the texas instruments TM320F2812 Digital Signal Processor (DSP) to generate SVPWM signal needed to trigger the gates of IGBT based inverter. The inverter used in this work is a three phase inverter IRAMY20UP60B type. The experimental results show the ability of the proposed control strategy to generate a three-phase sine wave signal with desired frequency. The proposed control strategy is experimented on a locally manufactured EV prototype. The results show that the EV prototype can be propelled to speed up to 60km/h under different road conditions.
Design and Implementation of Single Phase AC-DC Buck-Boost Converter for Powe...IJPEDS-IAES
This paper discusses the Power Factor Correction (PFC) for single phase AC-DC Buck-Boost Converter (BBC) operated in Continuous Conduction Mode (CCM) using inductor average current mode control. The proposed control technique employs Proportional-Integral (PI) controller in the outer voltage loop and the Inductor Average Current Mode Control (IACMC) in the inner current loop for PFC BBC. The IACMC has advantages such as robustness when there are large variations in line voltage and output load. The PI controller is developed by using state space average model of BBC. The simulation of the proposed system with its control circuit is implemented in MatLab/Simulink. The simulation results show a nearly unity power factor can be attained and there is almost no change in power factor when the line frequency is at various ranges. Experimental results are provided to show its validity and feasibility.
Improvement of Wind farm with PMSG using STATCOMIJPEDS-IAES
This paper studies about the dynamic performance of the Permanent Magnet Synchronous Generator with Static Synchronous Compensator (STATCOM) for Wind farm integration. A whole dynamic model of wind energy conversion system (WECS) with PMSG and STATCOM are established in a MATLAB environment. With this model the dynamic behaviour of the generator and the overall system has been studied to determine the performance of them with and without STATCOM. Final results portrays that the WECS based PMSG with STATCOM improves the transient response of the wind farm when the system is in fault.
Modeling and Control of a Doubly-Fed Induction Generator for Wind Turbine-Gen...IJPEDS-IAES
This paper presents a vector control direct (FOC) of double fed induction generator intended to control the generated stator powers. This device is intended to be implemented in a variable-speed wind-energy conversion system connected to the grid. In order to control the active and reactive power exchanged between the machine stator and the grid, the rotor is fed by a bi-directional converter. The DFIG is controlled by standard relay controllers. Details of the control strategy and system simulation were performed using Simulink and the results are presented in this here to show the effectiveness of the proposed control strategy.
A Review on Design and Development of high Reliable Hybrid Energy Systems wit...IJPEDS-IAES
Hybrid Energy system is a combination of two or more different types of energy resources. Now a day this hybrid energy system plays key role in various remote area power applications. Hybrid energy system is more reliable than single energy system. This paper deals with high reliable hybrid energy system with solar, wind and micro hydro resources. The proposed hybrid system cable of multi mode operation and high reliable due to non communicated based controllers (Droop Characteristic Control) are used for optimal power sharing. Size of battery can be reduced because hydro used as back up source and Maximum power point Tracking also applied to solar and wind energy systems.
Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024Sinan KOZAK
Sinan from the Delivery Hero mobile infrastructure engineering team shares a deep dive into performance acceleration with Gradle build cache optimizations. Sinan shares their journey into solving complex build-cache problems that affect Gradle builds. By understanding the challenges and solutions found in our journey, we aim to demonstrate the possibilities for faster builds. The case study reveals how overlapping outputs and cache misconfigurations led to significant increases in build times, especially as the project scaled up with numerous modules using Paparazzi tests. The journey from diagnosing to defeating cache issues offers invaluable lessons on maintaining cache integrity without sacrificing functionality.
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Software Engineering and Project Management - Introduction, Modeling Concepts...Prakhyath Rai
Introduction, Modeling Concepts and Class Modeling: What is Object orientation? What is OO development? OO Themes; Evidence for usefulness of OO development; OO modeling history. Modeling
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DEEP LEARNING FOR SMART GRID INTRUSION DETECTION: A HYBRID CNN-LSTM-BASED MODELijaia
As digital technology becomes more deeply embedded in power systems, protecting the communication
networks of Smart Grids (SG) has emerged as a critical concern. Distributed Network Protocol 3 (DNP3)
represents a multi-tiered application layer protocol extensively utilized in Supervisory Control and Data
Acquisition (SCADA)-based smart grids to facilitate real-time data gathering and control functionalities.
Robust Intrusion Detection Systems (IDS) are necessary for early threat detection and mitigation because
of the interconnection of these networks, which makes them vulnerable to a variety of cyberattacks. To
solve this issue, this paper develops a hybrid Deep Learning (DL) model specifically designed for intrusion
detection in smart grids. The proposed approach is a combination of the Convolutional Neural Network
(CNN) and the Long-Short-Term Memory algorithms (LSTM). We employed a recent intrusion detection
dataset (DNP3), which focuses on unauthorized commands and Denial of Service (DoS) cyberattacks, to
train and test our model. The results of our experiments show that our CNN-LSTM method is much better
at finding smart grid intrusions than other deep learning algorithms used for classification. In addition,
our proposed approach improves accuracy, precision, recall, and F1 score, achieving a high detection
accuracy rate of 99.50%.
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
Gas agency management system project report.pdfKamal Acharya
The project entitled "Gas Agency" is done to make the manual process easier by making it a computerized system for billing and maintaining stock. The Gas Agencies get the order request through phone calls or by personal from their customers and deliver the gas cylinders to their address based on their demand and previous delivery date. This process is made computerized and the customer's name, address and stock details are stored in a database. Based on this the billing for a customer is made simple and easier, since a customer order for gas can be accepted only after completing a certain period from the previous delivery. This can be calculated and billed easily through this. There are two types of delivery like domestic purpose use delivery and commercial purpose use delivery. The bill rate and capacity differs for both. This can be easily maintained and charged accordingly.
2. ISSN: 2088-8694
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217
L = (Dτ)1
/2
= (μ )1/2
(1)
where :
D : diffusion constant,
τ : average lifetime of free electrons,
μ : mobility,
K : Boltzmann's constant,
T : absolute temperature, and
q : electron charge.
Figure 1. Physical characteristics for a typical power diode
Solving for the total voltage drop across the junction, for a certain current value (I), gives [10]:
V = ln (2)
where:
W : base width,
A : area, and
ni : intrinsic carrier concentration.
Had the diffusion length been short compared to the base width, only a portion of the base region
would be in high injection. The electrons injected into the base region would recombine at a mean distance
(L) from the junction and a majority current would flow through the very high resistance base region.
However, the minority current flow through the ohmic resistance can be very high in the regions where n >
NA since the resistivity of silicon for NA=1.40x1014
/cm3
is about 130 Ω/cm. A high current through this high
resistivity region add significantly drop to the forward voltage. So, the forward voltage for a power diode is
kept small by a long diffusion length or a long minority carrier lifetime.
3. RADIATION PHYSICS
When high energy radiation is incident on a semiconductor device, the energy is deposited in the
semiconductor via two main mechanisms, atomic collisions and electronic ionizations. The relative
importance of these two mechanisms in a semi-conductor depends on both the type of radiation and the
nature of the device. For electrons, protons and gamma-rays environment, most of the deposited energy goes
into ionization processes, i.e., excitation and pair production. For fast neutrons environment, a large fraction
of the deposited energy results directly in atomic displacement damage from collisions.
The initially produced defect from gamma or electron-irradiation is quite simple and can be
expressed as a single displaced lattice atom and its associated vacancy (Frankel Defect [11]). On the other
hand, irradiation with fast neutrons produce regions of damage, each contains several hundred displaced
atoms. Hence, the interaction of radiation with semiconductor crystals is simply described by the number of
defects/cm3
created [12].
It can be shown that point defects (Frankel Defects) result in the introduction of allowed energy
states within the forbidden gap of the semiconductor [13] which affects mainly the minority carriers lifetime.
The degradation in minority carrier lifetime is usually expressed as:
3. IJPEDS ISSN: 2088-8694
Modeling the Dependence of Power Diode on Temperature and Radiation (S.M. El-Ghanam)
218
d(1/τ) / dΦ = Kτ, (3)
where, Kτ is the lifetime damage constant, and Φ is the radiation fluence.
Some literatures discuss a diffusion length damage as:
1 L ⁄ 1/L K ∅ (4)
Where, Lf, and L0 are the diffusion length after and before irradiation, and KL is the diffusion length damage
constant.
The effects of radiation on the power diode performances is mainly due to the change in lifetime of
minority carriers contained in the base region, which obeys the relations mentioned above. In this concern,
typical published values for the diffusion length damage constant (KL), for protons and electrons are
illustrated in Table 1 [14, 15]. On the other hand, for neutrons, it is observed that the damage constant is a
function of the injection ratio (n/p) and has the values listed in Table 2 [16, 17]. Finally, for gamma-radiation,
it is found that for cobalt-60, the diffusion length damage constant has a value of 1.27x10-11
particles-1
[18,
19].
Table 1. Diffusion length damage constant due to electrons and protons
Table 2. Diffusion length damage constant due to neutron irradiation
Damage constant [Particles-1
]Injection ratio
7.80 x 10-9
100
7.40 x 10-8
10-4
1.47 x 10-7
10-6
4. RESULTS AND DISCUSSIONS
Results obtained by Rageh, et al. [20] have been analyzed using the proposed computer program
(Appendix A) for calculating the diffusion length at high injection level and plotting the forward (I-V)
relationship.
The effect of different radiation types (gamma-rays, electrons, neutrons and protons), fluence (from
1.0x108/cm2 up to 1.0x1020/cm2) and energy (from 1.0 MeV up to 100 MeV) are studied. Also, the effect of
temperature variation (in the range from 300 K up to 800 K) is considered.
4.1. Temperature Effects
The forward (I–V) characteristics of the silicon power diode is calculated using the relation
mentioned in Eq. 2, where it is well known that both; voltage temperature coefficient (KT/q) and the intrinsic
concentration of electrons (ni) are temperature dependent [21]. In this concern, Figure 2 shows the effects of
temperature on the electrical properties of silicon power diode calculated using the proposed program. The
(I–V) curves shift profoundly towards the low values of drop voltage for the same forward current values, the
matter which was shown to be in close agreement with work done by X. Kang, et al., and published at online
Electronics Guide [22, 23].This effect, of course, is due to the increase in the voltage temperature coefficient
and the intrinsic carrier's density of the minority electrons contained in the base region of the diode with
increasing the temperature [21]. From which, a linear dependence of forward voltage on temperature was
obtained, as well, as empirical equation could be deduced as:
V = 1.37554 – 0.0015 T (5)
where, V is the forward voltage, and T is the temperature in Kelvin.
4.2. Radiation Effects
Permanent radiation damage in silicon power diodes is mainly attributed to the change in the
minority carriers lifetime. Consequently, the mean diffusion length of the carriers also changes. So, during
the present study, different radiation types were used and the corresponding damage effects on the diffusion
Protons [Particles-1
]Electrons [Particles-1
]Energy [MeV]
3.8 x 10-5
1.0 x 10-10
1
3.8 x 10-6
2.7 x 10-10
10
8.5 x 10-7
4.0 x 10-10
50
4.7 x 10-7
5.0 x 10-10
100
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219
length are represented in Figure 3. A pronounced reduction in the diffusion length occurs from its initial
value (137 µm) down to a certain value which depends on radiation type, fluence and energy.
The results are plotted for the different types of radiation, where it is noticed that radiation fluences
more than 109
/cm2
are shown to be effective, where it was found that a close agreement with those results
published by Carlson, et.al [24] was obtained. Damage due to proton irradiation is shown to be very strong
especially in the low energy band. For comparison, using a constant proton fluence of 1013
/cm2
, the diffusion
length was reduced to 48 µm and 130 µm for proton energies of 1.0 MeV and 100 MeV respectively. This
phenomenon, of course, does not hold for the case of electron irradiation, where the damage is shown to be a
direct function of both radiation fluence and energy.
In case of neutron irradiation, the damage occurs strongly for fluences above 1013
/cm2
depending
upon the injection ratio (n/p). Finally, gamma-rays produce the same damage on the diffusion length at
fluences higher than 1017
/cm2
.
The above mentioned damages are attributed to what is called "displacement cross-section" for the
radiation type and energy. Figure (4) indicates that the displacement cross-section for both gamma-and-
electron-radiation is a direct function of the energy [11, 12]. On the other hand, protons are charged particles,
similar to electrons, and it might be expected that both produce the same degree of damage. This is not the
case, because proton has larger mass and it can impart much more energy to the nucleus than an electron
when collisions with lattice occur.
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
0.0
0.5
1.0
1.5
2.0
ForwardCurrent,A
Forward Voltage, V
Temp.,K
800
600
500
400
300
(a)
200 300 400 500 600 700 800 900
0.0
0.2
0.4
0.6
0.8
1.0
ForwardVoltage,v
Temperature, K
V (Volt) = 1.37554 - 0.0015 * T 9K)
Cor. = -0.994
(b)
Figure 2. Effects of temperature on the forward (I-V) characteristic curves of Si-power diode (a)
and the linear dependence of the forward voltage on temperature,
calculated applying the developed computer programming (b)
1E8 1E14 1E20
0
20
40
60
80
100
120
140
160
DiffusionLength,um
Fluence, cm2
Neutrons, Injection Level :
10E-6
10E-4
1.0
Gamma-Rays
(a) (b)
Figure 3. Effects of radiation with different types, fluencies and energies on the diffusion length of the
silicon power diode {(a)- Neutrons and gamma-rays, and (b)-electrons and protons)}.
1E8 1E12 1E16 1E20
0
20
40
60
80
100
120
140
160
DiffusionLength,um
Fluene, cm2
ElectronsEnergy, MeV
1.0
10
100
ProtonsEnergy, MeV
100
10
1.0
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Modeling the Dependence of Power Diode on Temperature and Radiation (S.M. El-Ghanam)
220
Figure 4. Displacement cross section versus energy for silicon,
different radiation types are shown (compiled by the author).
For protons with higher energies, most of the energy may be transferred into kinetic energy and a
decrease in the displacement cross-section occurs due to the decrease in the possibility of proton capturing.
Sheng, S.L. [25] has performed numerical calculations of the total diode voltage drop as a function
of the ratio W/L for both ohmic and majority carrier contacts. Their results for the investigated silicon power
diode are considered.
The diffusion length, after exposure to radiation, can be obtained from the minority carrier lifetime
as:
/ /
∅
/
(6)
where, R and R0 are the recombination rates after and before irradiation, and Kτ is the minority carrier
lifetime damage constant.
On the other hand, the diode voltage is given in Figure 5 in terms of the voltage without injection or
I(eW/A) [20], where:
Ir = I(eW/A) = I W/qμANA (7)
Hence, from Figure 5, for the value of Ir and W/L, applied voltage can be obtained at various operating
conditions.
0.5 1.0 1.5 2.0 2.5 3.0 3.5
1
10
100
1000
I(WP/A),V
Applied Voltage, V
W /L = 5.0
W /L < 1.0
W /L = 7.0
Figure 5. Voltage-current relations for N+
PP+
power diode.
1 10 100
1E-21
1E-20
1E-19
Displacementcross-section
Energy, MeV
Gamma rays : range from 2.0E-24 up to 13.0E-24 cm2
Electrons : range from 2.0E-21 up to 28.0E-21 cm2
Protons : range from 1.0E-21 up to 3.0E-19 cm2
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221
The obtained results, after introducing the effects of radiation, on the equations mentioned above,
are shown in Figures 6 through 8. A large increase in the forward voltage value is shown for the same
forward current, closely identical with the results published by J.R.Srour [26]. This increase is a function of;
radiation type, energy and fluence. It is so easy to notice that for all the radiation processes, the device loses
its main features as a rectifying device and behaves as a linear resistance at a certain radiation fluence. As an
example, for electron (with energy of 1.0 MeV) with fluence value of 5.4x1019
/cm2
results in the device
complete damage. Increasing the energy of the incident electrons up to 100 MeV causes the diode breakdown
at less fluence levels (9x1018
/cm2
). Moreover, diode failure due to proton irradiation occurs at 1.54 x1014
/cm2
and 1.1x1017
/cm2
for proton energies of 1.0 MeV and 100 MeV respectively.
Higher gamma-fluences are shown necessary to affect the power silicon diode performances (Fig.
8). A threshold fluence value of 5.0x1018
/cm2
is just required to increase the forward voltage from its initial
value of 0.8 V (at 0.3 A of forward current) up to 1.05 V and a fluence value of 4.25x1020
/cm2
is enough for
diode forward failure.
1E14 1E15 1E16 1E17 1E18 1E19 1E20
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
1.0
10
50
100
Electron Energy, MeV:
ForwardVoltage,v
Electron Fuence, cm2
(a)
1E11 1E12 1E13 1E14 1E15 1E16 1E17 1E18
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Proton Energy; MeV :
1.0
10
50
100
ForwardVoltage,V
Proton Fluence, cm2
(b)
Figure 6. Effects of electron (a)- and proton (b) -irradiations with different fluences and energies
on the forward voltage of the silicon power diode (IF = 0.3 A).
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
4.25E20
3.1E20
1.36E20
5E18
0
NeutronFluence, cm2:
ForwardCurrent,A
ForwardVoltage, V
0.00E+000 2.00E+020 4.00E+020 6.00E+020
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
ForwardVoltage,V
NeutronsIrradiationFluence,cm2
V=0.838+4.96E-21*Fluence
Cr.=0.991
Figure 7. Effects of neutron irradiation on the forward voltage drop of silicon power diode (IF = 0.3 A).
7. IJPEDS ISSN: 2088-8694
Modeling the Dependence of Power Diode on Temperature and Radiation (S.M. El-Ghanam)
222
1E14 1E15 1E16 1E17 1E18
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
n/p =1E-6n/p = 1E-4
n/p =1
ForwardVoltage,V
Gamma-Irradiation Fluence, cm2
Figure 8. Effects of gamma irradiation with different fluences on the forward
voltage drop of the silicon power diode (IF=0.3 A).
Finally, Figure 9 shows a comparison for the calculated changes in forward voltage values due to
radiation exposure with different type, energy and fluence.
1E8 1E14 1E20
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
ForwardVoltage,V
Fluence, cm2
Protons, 10 MeV
Neutrons, n/p=10E-6
Electrons, 100 MeV
Electrons, 1.0 MeV
Gamma-Rays, C0-60
Figure 9. Calculated change in forward voltage values due to radiation
exposure with different type, energy and fluence.
5. CONCLUSION
A computer program has been developed to analyze the characteristics of power silicon diode under
the influence of various radiation types and temperature variation conditions. From which, it was found that
increasing the device temperature interrupts its (I-V) curves in the direction of decreasing the forward voltage
for the same forward current values. As well, an increase in the integrated radiation flux causes a
monotonous increase in the forward voltage and differential resistance and the silicon diode tends to become
a linear high ohmic resistor.
Irradiation with low energy protons has strong effect where the device is completely damaged at
1.45x1014
/cm2
. On the other hand, gamma-rays emitted from cobalt-60 source causes the same defect on
devices at 4.25x1020
/cm2
. On the other hand the damage effect caused by electrons and neutrons irradiation
lies between that obtained by protons and gamma. All defects are shown to be function of radiation type,
fluence and energy.
8. ISSN: 2088-8694
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223
Appendix A
The following program has been developed by the authors to carry out the calculations of power diode
characteristics under different operating conditions of temperature and radiation exposure. As well, here
follows the definitions of the symbols used in the mentioned program:
WOL: W/L
NA: NA
UN: mobility
KTOQ: KT/q
AKL: diffusion length damage constant
RAD: radiation fluence
LF: diffusion length after irradiation
DN: diffusion constant
10 REM PROG "PDRAD2013"
20 OPTION BASE 1
30 DIM I(30), IR(30), RAD(3O), Z1(3O),
Z2(3O), Z3(30), Z4(30)
40 DIM Z5(30), Z6(30), Z7(30), LF(30),
WOL(30), V(30).
50 Q = 1.6 E -19
60 UP = 500
70 A = 0.01
80 NA = 1.2 E 14
90 L = 0.000137
100 W = 0.000095
110 TINF = 0.000005
120 ND = 1.0 E 9
130 UN = 1440
140 K = 1.38 E -23
150 DN = 37
160 FOR J = 1 TO 21
170 READ I(J)
180 NEXT J
190 DATA. 05, .1, .2, .3, .4, .5, .6, .7, .8, .9,1, 1.1,
1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0
200 FOR J = 1 TO 13
210 READ RAD(J)
220 NEXT J
230 DATA 1E8, lE9, 1El0, lEll, lEl2, lEl3, lEl4,
1E15, lE16, lE17,1E18, lE19, lE20
240 INPUT T
250 INPUT AKL
260 IF T = 250 THEN 270 ELSE 290
270 NI = 1.7 E 8
280 GOTO 460
290 IF T = 300 THEN 300 ELSE 320
300 NI =1.5E10
310 GOTO 460
320 IF T = 400 THEN 330 ELSE 350
330 NI = 8 E 12
340 GOTO 460
350 IF T = 500 THEN 360 ELSE 380
360 NI = 4E14
370 GOTO 460
380 IF T = 600 THEN 390 ELSE 410
390 NI =5E16
400 GOTO 460
410 IF T = 700 THEN 420 ELSE 440
420 NI =2.5E16
430 GOTO 460
440 IF T = 800 THEN 450 ELSE 470
450 NI = 2.0 E 17
460 LPRINT "T =";T;"NI=";NI
470 KTOQ = KT/Q
480 Z4 = 2 Q * A * D * NI
490 FOR J 1 TO 21
500 Z5(J) = I(J)/W
510 Z6(J) = Z5(J)/Z4
520 Z7(J) = LOG(Z6(J))
530 V(J) = 2* KTG(OQ * Z7(J)
540 NEXT J
550 LPRINT "******************"
560 FOR J = 1 TO 21
570 LPRINT J, I(J), V(J)
580 NEXT J
590 LPRINT "AKL = ";AKL
600 FOR J = 1 TO 13
610 Z(J) = (AKL * RAD(J))*(L**2)
620 Zl(J) = 1 + Z(J)
630 Z2(J) = (L**2)/Zl(J)
640 Z3(J) = SQR(Z2(J))
650 LF(J) = Z3(J)
660 WOL(J) = W/(LF(J))
670 NEXT J
680 LPRINT"********************"
690 FOR J = 1 TO 25
700 LPRINTJ, RAD(J), LF(J), WOL(J)
710 NEXT J
720 LPRINT"********************"
730 FOR J = 1 TO 21
740 IR(J) = (I(J)*W)/(Q*UP*A*NA)
750 NEXT J
760 FOR J = 1 TO 21
770 LPRINT J, I(J), IR(J)
780 NEXT J
790 LPRINT"*******************"
800 END
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