The document describes the design and construction of a prototype transversely excited atmospheric (TEA) nitrogen laser energized by a high voltage electrical discharge. Key aspects include:
1) The laser uses a Blumlein line discharge circuit to excite nitrogen gas in air using air as the active lasing medium, producing 337.1 nm wavelength laser output of 300 microjoules.
2) The design includes two parallel plate capacitors connected by an inductor to form a Blumlein circuit, charged by a high voltage flyback transformer-based power supply producing 10-20 kV.
3) A spark gap triggers the electrical energy to excite air molecules in the laser discharge channel between two electrodes, producing population
This summary provides the key points about a study on frequency-tracking wireless power transfer systems using resonant coupling:
1) Detuning is a barrier to resonant coupling wireless power transfer, as changes in coil inductances can reduce transmission efficiency.
2) A new frequency tracking control method is proposed where the transmitting power source frequency tracks the natural frequency of the launching resonant circuit automatically to avoid detuning and improve efficiency.
3) An experimental 1 MHz wireless power transfer prototype was built using this frequency tracking method, and results showed it performed well in maintaining high transmission efficiency despite changes in coil inductances.
The fundamental base of plasma antenna is the use of an ionized medium as a conductor. The plasma antenna is a radiofrequency antenna formed by a plasma columns, Filaments or sheets, which are excited by a surface wave. The relevance of this device is how rapidly it can be turned on and off, only applying an electrical pulse. Besides its wide carrier frequency, the great directivity and controllable antenna shape. Otherwise a disadvantage is that it needs energy to be ionized. There are studies to reduce this power to ionize and maintain the plasma tube with higher plasma densities and frequencies.
Analysis and Design of Lead Salt PbSe/PbSrSe Single Quantum Well In the Infra...IJASCSE
There is a considerable interest in studying the energy spectrum changes due to the non parabolic energy band structure in nano structures and nano material semiconductors. Most material systems have parabolic band structures at the band edge, however away from the band edge the bands are strongly non parabolic. Other material systems are strongly parabolic at the band edge such as IV-VI lead salt semiconductors. A theoretical model was developed to conduct this study on PbSe/Pb 0.934 Sr0.066 Se nanostructure system in the infrared region. Moreover, we studied the effects of four temperatures on the analysis and design of this system. It will be shown that the total losses for the system are higher than the modal gain values for lasing to occur and multiple quantum well structures are a better design choice.
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.
Spectroscopy is the science that deals with interactions between electromagnetic radiation and matter. It involves transitions between energy levels of atoms and molecules when they absorb or emit photons. Different regions of the electromagnetic spectrum, such as visible light, ultraviolet light, infrared light, and radio waves, can be used in spectroscopy. Absorption spectroscopy measures the absorption of radiation to identify substances based on their unique absorption patterns. Beer's law describes the relationship between absorbance of a sample and its concentration.
Plasma Antenna
Plasma antennas represent a new technology that uses ionized gas or plasma instead of metal as the conducting element. When gas is ionized it becomes conductive and allows radio signals to be transmitted or received. Plasma antennas have advantages over traditional metal antennas such as higher efficiency, gain, and bandwidth. They are also lighter weight, dynamically reconfigurable, and invisible to radar. Potential applications include military communications, broadcasting, and future wireless technologies requiring high speeds such as 5G.
Plasma is the fourth state of matter similar to gas that is identified by charged and neutral particles. Plasma antennas employ ionized gas enclosed in a tube as a conducting element. When a gas is ionized into plasma through applied voltage, it becomes conductive and allows radio signals to be transmitted or received. Key advantages of plasma antennas include higher power, enhanced bandwidth, higher efficiency, and the ability to operate at frequencies up to 90 GHz. They also have applications in high-speed communication, radar systems, and military stealth technologies.
The feasibility of a dimmer and neon transformer to provide power control to the atmospheric pressure plasma jet (APPJ) is presented in this paper. The standard neon transformer was previously shown applicable to power up a plasma torch to generate plasma irradiation of an APPJ at 8.64kv and 35kHz. However, the plasma emission is not controllable. In this study, a lamp dimmer was proposed to function as a power controller to the neon transformer which drives the generation of plasma and discharged with argon gas. With the dimmer output voltage adjustable from 60 - 220V, the power and current of the dimmer were variable from 8.4 to 83.6 W and 0.08 and 0.38 A, respectively. The temperature measured at the quartz tube and sample exposure site were less than 50oC suggested that the APPJ produced were non-thermal. A simple test by exposing plasma plume to a leaf sample showed that the plasma produced were non-damaging to the leaf. This portable system can provide control to the APPJ and applicable for bioengineering studies.
This summary provides the key points about a study on frequency-tracking wireless power transfer systems using resonant coupling:
1) Detuning is a barrier to resonant coupling wireless power transfer, as changes in coil inductances can reduce transmission efficiency.
2) A new frequency tracking control method is proposed where the transmitting power source frequency tracks the natural frequency of the launching resonant circuit automatically to avoid detuning and improve efficiency.
3) An experimental 1 MHz wireless power transfer prototype was built using this frequency tracking method, and results showed it performed well in maintaining high transmission efficiency despite changes in coil inductances.
The fundamental base of plasma antenna is the use of an ionized medium as a conductor. The plasma antenna is a radiofrequency antenna formed by a plasma columns, Filaments or sheets, which are excited by a surface wave. The relevance of this device is how rapidly it can be turned on and off, only applying an electrical pulse. Besides its wide carrier frequency, the great directivity and controllable antenna shape. Otherwise a disadvantage is that it needs energy to be ionized. There are studies to reduce this power to ionize and maintain the plasma tube with higher plasma densities and frequencies.
Analysis and Design of Lead Salt PbSe/PbSrSe Single Quantum Well In the Infra...IJASCSE
There is a considerable interest in studying the energy spectrum changes due to the non parabolic energy band structure in nano structures and nano material semiconductors. Most material systems have parabolic band structures at the band edge, however away from the band edge the bands are strongly non parabolic. Other material systems are strongly parabolic at the band edge such as IV-VI lead salt semiconductors. A theoretical model was developed to conduct this study on PbSe/Pb 0.934 Sr0.066 Se nanostructure system in the infrared region. Moreover, we studied the effects of four temperatures on the analysis and design of this system. It will be shown that the total losses for the system are higher than the modal gain values for lasing to occur and multiple quantum well structures are a better design choice.
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.
Spectroscopy is the science that deals with interactions between electromagnetic radiation and matter. It involves transitions between energy levels of atoms and molecules when they absorb or emit photons. Different regions of the electromagnetic spectrum, such as visible light, ultraviolet light, infrared light, and radio waves, can be used in spectroscopy. Absorption spectroscopy measures the absorption of radiation to identify substances based on their unique absorption patterns. Beer's law describes the relationship between absorbance of a sample and its concentration.
Plasma Antenna
Plasma antennas represent a new technology that uses ionized gas or plasma instead of metal as the conducting element. When gas is ionized it becomes conductive and allows radio signals to be transmitted or received. Plasma antennas have advantages over traditional metal antennas such as higher efficiency, gain, and bandwidth. They are also lighter weight, dynamically reconfigurable, and invisible to radar. Potential applications include military communications, broadcasting, and future wireless technologies requiring high speeds such as 5G.
Plasma is the fourth state of matter similar to gas that is identified by charged and neutral particles. Plasma antennas employ ionized gas enclosed in a tube as a conducting element. When a gas is ionized into plasma through applied voltage, it becomes conductive and allows radio signals to be transmitted or received. Key advantages of plasma antennas include higher power, enhanced bandwidth, higher efficiency, and the ability to operate at frequencies up to 90 GHz. They also have applications in high-speed communication, radar systems, and military stealth technologies.
The feasibility of a dimmer and neon transformer to provide power control to the atmospheric pressure plasma jet (APPJ) is presented in this paper. The standard neon transformer was previously shown applicable to power up a plasma torch to generate plasma irradiation of an APPJ at 8.64kv and 35kHz. However, the plasma emission is not controllable. In this study, a lamp dimmer was proposed to function as a power controller to the neon transformer which drives the generation of plasma and discharged with argon gas. With the dimmer output voltage adjustable from 60 - 220V, the power and current of the dimmer were variable from 8.4 to 83.6 W and 0.08 and 0.38 A, respectively. The temperature measured at the quartz tube and sample exposure site were less than 50oC suggested that the APPJ produced were non-thermal. A simple test by exposing plasma plume to a leaf sample showed that the plasma produced were non-damaging to the leaf. This portable system can provide control to the APPJ and applicable for bioengineering studies.
This document outlines a presentation on plasma antenna technology. It begins with an introduction to plasma antennas, noting that they replace the metal elements of conventional antennas with ionized gas plasma. It then covers the classification, frequency properties, and working principles of plasma, including how ionized gas plasma can be used as the conducting element in an antenna. The document discusses plasma antenna applications in areas like high-speed communication and radar due to advantages like higher power and efficiency compared to traditional antennas. It concludes that plasma antennas are more advantageous than other antenna types for applications requiring ionized gas and pulse operation.
The term plasma antenna has been applied to a wide variety of antenna concepts that incorporate some use of an ionized medium. In the vast majority of approaches, the plasma, or ionized volume, simply replaces a solid conductor. A highly ionized plasma is essentially a good conductor, and therefore plasma filaments can serve as transmission line elements for guiding waves, or antenna surfaces for radiation.
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
The document describes a plasma antenna. It begins with an introduction to plasma, explaining that plasma is ionized gas that responds to electromagnetic fields. It then discusses plasma antennas, noting that they use plasma instead of metal for conduction and can be used for both transmission and reception. The document goes on to cover the features, working principle, advantages, disadvantages, applications, and future scope of plasma antennas. It concludes by stating that plasma antennas work similarly to traditional antennas but with plasma replacing the metal conductor, offering advantages like invisibility to radar and ability to transmit short pulses.
The document discusses plasma antennas, which use ionized gas as the conducting element instead of metal. Plasma antennas have several advantages over traditional metal antennas, such as being lightweight, compact, and able to transmit and receive from the same aperture. They can also be dynamically configured and steered electronically without moving parts. Various types of plasma antennas are described, including those using tube structures and explosively formed plasma. Potential applications include military, communications, and radar systems.
The document discusses plasma antennas, which use ionized gas instead of metal conductors. Plasma antennas have advantages over traditional antennas like higher efficiency and enhanced bandwidth. They operate by ionizing a gas to create plasma that can radiate or receive radio waves. However, plasma antennas also have limitations like higher costs and not being suitable for mobile use. The document reviews the basic principles, operation, characteristics, advantages, limitations and applications of plasma antennas.
This document provides an overview of transmission line modeling and analysis. It begins with assigning homework problems and then reviews electric field concepts such as Gauss's law and voltage difference calculations. Models for transmission line capacitance and inductance are developed considering both single and multi-conductor cases. Examples are provided to demonstrate how to calculate per phase capacitance, resistance, and inductance values for different conductor types using data from standard tables. Additional transmission line topics like multi-circuit lines, underground cables, and corona discharge are also briefly discussed.
Quantum transport in semiconductor nanostructuressamrat saurabh
This document discusses quantum transport in semiconductor nanostructures. It begins by providing background on semiconductors, including their electrical properties between conductors and insulators. When sized below a certain limit, nanostructures constructed from semiconductors exhibit new electronic and optical properties due to quantization effects. An example is a quantum dot formed from a semiconductor with 5-10nm thickness. The document then discusses different types of quantum transport, including diffusive and ballistic transport, and provides examples of applications of semiconductor nanostructures in areas like lasers and quantum computing.
The document summarizes research on understanding charge transport in low dimensional semiconductor nanostructures embedded in an insulating matrix. Specifically, it examines current-voltage characteristics of germanium nanowire arrays in an alumina matrix as a function of temperature. Key findings include:
1) At room temperature, conduction follows Ohm's law at low voltages and Mott-Gurney's space charge limited current law at higher voltages.
2) With decreasing temperature, conduction transitions from a trap-free regime to an exponentially distributed trap regime.
3) Mobility decreases with decreasing temperature, and activation energy is extracted from an Arrhenius plot, found to be 85 meV at low temperatures and 301 meV
Beam generation and planar imaging at energies below 2.40 MeV with carbon and...David Parsons
This study investigated generating low-energy x-ray beams below 2.40 MeV using carbon and aluminum linear accelerator targets for improved planar imaging quality. The authors were able to lower the incident electron energy to between 1.90 and 2.35 MeV by adjusting the bending magnet current on a Varian linac. They measured an increase in contrast-to-noise ratio of cortical bone of 3.7-7.4 times compared to a standard 6 MV therapy beam, with only a slight degradation of spatial resolution at lower energies. Monte Carlo simulations showed that 46-54% of the generated photons were in the diagnostic energy range.
This document discusses electronic transitions in hydrogen atoms that produce spectral lines. It explains that electrons in hydrogen atoms exist in discrete energy levels called principal quantum levels. Transitions between these levels emit or absorb photons of specific wavelengths. The Lyman, Balmer, and Paschen series are produced by transitions from higher levels to the n=1, n=2, and n=3 levels, respectively. Precise wavelengths are given for the lines in the Balmer series in the visible spectrum. Bohr's model of the hydrogen atom is able to accurately predict the wavelengths of these spectral lines.
SRIM Calculations Applied to Ionization Chambers Tyler BaileyTyler Bailey
1) SRIM simulations were used to model the interaction of alpha particles in different gases to determine the ideal gas for an ionization chamber. Argon gas was found to be optimal as it produced the largest voltage signal for a given alpha energy due to its high atomic number and low ionization potential.
2) The simulations calculated ion pairs produced and voltage pulses for various alpha energies in different gases. Argon had the highest ion pair production and voltage pulses, making it suitable for compact ionization chamber designs.
3) The voltage pulses could be used to determine the alpha energy interacting in the chamber, allowing identification of radioactive sources. However, more sophisticated processing is needed to account for other radiation types.
This document presents information on plasma antennas. It begins with an introduction to plasma and its discovery. It then discusses how plasma antennas work, with plasma replacing metal as the antenna element. Plasma antennas can be used for both transmission and reception. Their working principle involves ionizing a gas inside a tube to form plasma, which then behaves as a conductor and emits electromagnetic waves when RF signals are applied. Plasma antennas offer advantages like being lighter than conventional antennas and having higher efficiency, but also have disadvantages like higher power consumption. Potential applications include use in stealth aircraft, high speed data communication, and broadband jamming.
The document discusses plasma antennas, which use ionized gas or plasma instead of metal for signal conduction. Plasma antennas have several advantages over traditional metal antennas, such as the ability to focus beams, transmit short pulses, and reconfigure frequency and direction electronically. Different types are described, including laser-induced antennas and those using tube structures. The document explains that plasma antennas work by generating localized plasma concentrations that act as mirrors to deflect radio frequency beams. Potential applications include military, aviation, and broadband communications uses.
1. the role of microwaves in lips (frontiers of physics if 2.4)Ali Khumaeni
1) Microwaves were injected into a laser-induced plasma on a calcium oxide pellet via a loop antenna to study their effect on plasma emission enhancement.
2) When microwaves were applied, the plasma lifetime was extended from 50 to 500 microseconds, similar to the microwave duration. The plasma temperature increased to around 10,900 K and electron density to 1.5×1018 cm-3.
3) The emission intensity of calcium lines was enhanced by around 200 times when microwaves were used compared to laser-induced breakdown spectroscopy without microwaves. This was due to the extended plasma lifetime and higher plasma temperature and electron density when microwaves were applied.
Plasma is one of the advanced technology in semi conducting materials. Scientists states that 99% of the universe is covered with plasma. Plasma Antenna is a special type of antenna in which metal conducting elements of conventional antenna are replaced by plasma. Its 4th state of matter similar to gas. It employs ionized gas enclosed in a tube as conducting element of an antenna. When the gas is electrically charged or ionized to plasma, it becomes conductive & allowing radio frequency signals to be transmitted or received. When gas is not ionized, the antenna elements ceases to exit. When voltage is applied to an antenna, electric field is produced which causes current to flow in antenna. Due to current flow, magnetic field is produced. It is more advantageous than other antenna due to ionized gas. It has higher effiency & enhanced bandwidth. The fact that the emitting element is formed over the interval needed for the emission of an electromagnetic pulse is an important advantage of plasma antennas . In the passive state (in the absence of plasma in the discharge tube),such a device does not exhibit electric conductivity. A plasma stream flowing from a jet into the ambient space , the plasma trace of a body moving at an ultrasonic velocity in the atmosphere , and alternative plasma objects have been studied as possible antenna elements.
Metal antennas currently in implementation use metallic conductor as guiding medium for electromagnetic radiations. Plasma antennas uses ionized medium. The plasma antenna is a radiofrequency antenna formed by a plasma columns, filaments or sheets, which are excited by a surface wave. The relevance of this device is how rapidly it can be turned on and off only applying an electrical pulse. Unlike traditional metal antenna, plasma antenna is based on partially or fully ionized gas used as a conducting material
Plasma antennas find its applications in variety of fields due its unique properties, characteristics and advantages over traditional metallic antennas.
i) Faster internet
ii) Public safety networks
iii) Radio and television broadcasting
iv) Space communication
Modelling Quantum Transport in Nanostructuresiosrjce
IOSR Journal of Electronics and Communication Engineering(IOSR-JECE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of electronics and communication engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electronics and communication engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Propagation of ELF Radiation from RS-LC System and Red Sprites in Earth- Iono...degarden
This document compares the propagation of extremely low frequency (ELF) radiation from return stroke-lateral corona (RS-LC) systems and red sprites in the Earth-ionosphere waveguide. It finds that red sprites contribute more greatly to Schumann resonances than RS-LC systems. The document derives mathematical expressions to model the velocity, current, and current moment of RS-LC systems and red sprites. It then uses these expressions to calculate the electric and magnetic fields generated by RS-LC systems and red sprites, finding that red sprites produce fields on the order of 10-5 V/m and 10-8 A/m, peaking at Schumann resonance frequencies.
Analysis of MOS Capacitor Loaded Annular Ring MICROSTRIP AntennaIJMER
In this paper a new technique is proposed for achieving increased frequency agility by loading
the patch antenna with a MOS capacitor. Theoretical investigations have been carried out for the MOS
capacitor loaded Annular Ring microstrip antenna, for oxide thicknesses from 100 A to 500 A, to predict
the achievable range of operational bandwidth. In spite of numerous advantages, the simple patch antenna
has a low operational bandwidth, which limits its applicability. Hence this technique of MOS capacitor
loaded Annular Ring microstrip patch antenna is to improve the operating frequency range.
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 discusses several rules and techniques of photography including:
1. The rule of thirds, which divides the frame into thirds both horizontally and vertically to place the subject near the intersection points.
2. Framing focuses the viewer's attention by using elements like windows, doors, or natural frames.
3. Leading lines guide the eye through the photograph from the front to the back along lines like paths, roads, or edges.
4. Balancing elements creates interest by placing the main subject off-center and filling empty space with other objects.
This document outlines a presentation on plasma antenna technology. It begins with an introduction to plasma antennas, noting that they replace the metal elements of conventional antennas with ionized gas plasma. It then covers the classification, frequency properties, and working principles of plasma, including how ionized gas plasma can be used as the conducting element in an antenna. The document discusses plasma antenna applications in areas like high-speed communication and radar due to advantages like higher power and efficiency compared to traditional antennas. It concludes that plasma antennas are more advantageous than other antenna types for applications requiring ionized gas and pulse operation.
The term plasma antenna has been applied to a wide variety of antenna concepts that incorporate some use of an ionized medium. In the vast majority of approaches, the plasma, or ionized volume, simply replaces a solid conductor. A highly ionized plasma is essentially a good conductor, and therefore plasma filaments can serve as transmission line elements for guiding waves, or antenna surfaces for radiation.
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
The document describes a plasma antenna. It begins with an introduction to plasma, explaining that plasma is ionized gas that responds to electromagnetic fields. It then discusses plasma antennas, noting that they use plasma instead of metal for conduction and can be used for both transmission and reception. The document goes on to cover the features, working principle, advantages, disadvantages, applications, and future scope of plasma antennas. It concludes by stating that plasma antennas work similarly to traditional antennas but with plasma replacing the metal conductor, offering advantages like invisibility to radar and ability to transmit short pulses.
The document discusses plasma antennas, which use ionized gas as the conducting element instead of metal. Plasma antennas have several advantages over traditional metal antennas, such as being lightweight, compact, and able to transmit and receive from the same aperture. They can also be dynamically configured and steered electronically without moving parts. Various types of plasma antennas are described, including those using tube structures and explosively formed plasma. Potential applications include military, communications, and radar systems.
The document discusses plasma antennas, which use ionized gas instead of metal conductors. Plasma antennas have advantages over traditional antennas like higher efficiency and enhanced bandwidth. They operate by ionizing a gas to create plasma that can radiate or receive radio waves. However, plasma antennas also have limitations like higher costs and not being suitable for mobile use. The document reviews the basic principles, operation, characteristics, advantages, limitations and applications of plasma antennas.
This document provides an overview of transmission line modeling and analysis. It begins with assigning homework problems and then reviews electric field concepts such as Gauss's law and voltage difference calculations. Models for transmission line capacitance and inductance are developed considering both single and multi-conductor cases. Examples are provided to demonstrate how to calculate per phase capacitance, resistance, and inductance values for different conductor types using data from standard tables. Additional transmission line topics like multi-circuit lines, underground cables, and corona discharge are also briefly discussed.
Quantum transport in semiconductor nanostructuressamrat saurabh
This document discusses quantum transport in semiconductor nanostructures. It begins by providing background on semiconductors, including their electrical properties between conductors and insulators. When sized below a certain limit, nanostructures constructed from semiconductors exhibit new electronic and optical properties due to quantization effects. An example is a quantum dot formed from a semiconductor with 5-10nm thickness. The document then discusses different types of quantum transport, including diffusive and ballistic transport, and provides examples of applications of semiconductor nanostructures in areas like lasers and quantum computing.
The document summarizes research on understanding charge transport in low dimensional semiconductor nanostructures embedded in an insulating matrix. Specifically, it examines current-voltage characteristics of germanium nanowire arrays in an alumina matrix as a function of temperature. Key findings include:
1) At room temperature, conduction follows Ohm's law at low voltages and Mott-Gurney's space charge limited current law at higher voltages.
2) With decreasing temperature, conduction transitions from a trap-free regime to an exponentially distributed trap regime.
3) Mobility decreases with decreasing temperature, and activation energy is extracted from an Arrhenius plot, found to be 85 meV at low temperatures and 301 meV
Beam generation and planar imaging at energies below 2.40 MeV with carbon and...David Parsons
This study investigated generating low-energy x-ray beams below 2.40 MeV using carbon and aluminum linear accelerator targets for improved planar imaging quality. The authors were able to lower the incident electron energy to between 1.90 and 2.35 MeV by adjusting the bending magnet current on a Varian linac. They measured an increase in contrast-to-noise ratio of cortical bone of 3.7-7.4 times compared to a standard 6 MV therapy beam, with only a slight degradation of spatial resolution at lower energies. Monte Carlo simulations showed that 46-54% of the generated photons were in the diagnostic energy range.
This document discusses electronic transitions in hydrogen atoms that produce spectral lines. It explains that electrons in hydrogen atoms exist in discrete energy levels called principal quantum levels. Transitions between these levels emit or absorb photons of specific wavelengths. The Lyman, Balmer, and Paschen series are produced by transitions from higher levels to the n=1, n=2, and n=3 levels, respectively. Precise wavelengths are given for the lines in the Balmer series in the visible spectrum. Bohr's model of the hydrogen atom is able to accurately predict the wavelengths of these spectral lines.
SRIM Calculations Applied to Ionization Chambers Tyler BaileyTyler Bailey
1) SRIM simulations were used to model the interaction of alpha particles in different gases to determine the ideal gas for an ionization chamber. Argon gas was found to be optimal as it produced the largest voltage signal for a given alpha energy due to its high atomic number and low ionization potential.
2) The simulations calculated ion pairs produced and voltage pulses for various alpha energies in different gases. Argon had the highest ion pair production and voltage pulses, making it suitable for compact ionization chamber designs.
3) The voltage pulses could be used to determine the alpha energy interacting in the chamber, allowing identification of radioactive sources. However, more sophisticated processing is needed to account for other radiation types.
This document presents information on plasma antennas. It begins with an introduction to plasma and its discovery. It then discusses how plasma antennas work, with plasma replacing metal as the antenna element. Plasma antennas can be used for both transmission and reception. Their working principle involves ionizing a gas inside a tube to form plasma, which then behaves as a conductor and emits electromagnetic waves when RF signals are applied. Plasma antennas offer advantages like being lighter than conventional antennas and having higher efficiency, but also have disadvantages like higher power consumption. Potential applications include use in stealth aircraft, high speed data communication, and broadband jamming.
The document discusses plasma antennas, which use ionized gas or plasma instead of metal for signal conduction. Plasma antennas have several advantages over traditional metal antennas, such as the ability to focus beams, transmit short pulses, and reconfigure frequency and direction electronically. Different types are described, including laser-induced antennas and those using tube structures. The document explains that plasma antennas work by generating localized plasma concentrations that act as mirrors to deflect radio frequency beams. Potential applications include military, aviation, and broadband communications uses.
1. the role of microwaves in lips (frontiers of physics if 2.4)Ali Khumaeni
1) Microwaves were injected into a laser-induced plasma on a calcium oxide pellet via a loop antenna to study their effect on plasma emission enhancement.
2) When microwaves were applied, the plasma lifetime was extended from 50 to 500 microseconds, similar to the microwave duration. The plasma temperature increased to around 10,900 K and electron density to 1.5×1018 cm-3.
3) The emission intensity of calcium lines was enhanced by around 200 times when microwaves were used compared to laser-induced breakdown spectroscopy without microwaves. This was due to the extended plasma lifetime and higher plasma temperature and electron density when microwaves were applied.
Plasma is one of the advanced technology in semi conducting materials. Scientists states that 99% of the universe is covered with plasma. Plasma Antenna is a special type of antenna in which metal conducting elements of conventional antenna are replaced by plasma. Its 4th state of matter similar to gas. It employs ionized gas enclosed in a tube as conducting element of an antenna. When the gas is electrically charged or ionized to plasma, it becomes conductive & allowing radio frequency signals to be transmitted or received. When gas is not ionized, the antenna elements ceases to exit. When voltage is applied to an antenna, electric field is produced which causes current to flow in antenna. Due to current flow, magnetic field is produced. It is more advantageous than other antenna due to ionized gas. It has higher effiency & enhanced bandwidth. The fact that the emitting element is formed over the interval needed for the emission of an electromagnetic pulse is an important advantage of plasma antennas . In the passive state (in the absence of plasma in the discharge tube),such a device does not exhibit electric conductivity. A plasma stream flowing from a jet into the ambient space , the plasma trace of a body moving at an ultrasonic velocity in the atmosphere , and alternative plasma objects have been studied as possible antenna elements.
Metal antennas currently in implementation use metallic conductor as guiding medium for electromagnetic radiations. Plasma antennas uses ionized medium. The plasma antenna is a radiofrequency antenna formed by a plasma columns, filaments or sheets, which are excited by a surface wave. The relevance of this device is how rapidly it can be turned on and off only applying an electrical pulse. Unlike traditional metal antenna, plasma antenna is based on partially or fully ionized gas used as a conducting material
Plasma antennas find its applications in variety of fields due its unique properties, characteristics and advantages over traditional metallic antennas.
i) Faster internet
ii) Public safety networks
iii) Radio and television broadcasting
iv) Space communication
Modelling Quantum Transport in Nanostructuresiosrjce
IOSR Journal of Electronics and Communication Engineering(IOSR-JECE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of electronics and communication engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electronics and communication engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Propagation of ELF Radiation from RS-LC System and Red Sprites in Earth- Iono...degarden
This document compares the propagation of extremely low frequency (ELF) radiation from return stroke-lateral corona (RS-LC) systems and red sprites in the Earth-ionosphere waveguide. It finds that red sprites contribute more greatly to Schumann resonances than RS-LC systems. The document derives mathematical expressions to model the velocity, current, and current moment of RS-LC systems and red sprites. It then uses these expressions to calculate the electric and magnetic fields generated by RS-LC systems and red sprites, finding that red sprites produce fields on the order of 10-5 V/m and 10-8 A/m, peaking at Schumann resonance frequencies.
Analysis of MOS Capacitor Loaded Annular Ring MICROSTRIP AntennaIJMER
In this paper a new technique is proposed for achieving increased frequency agility by loading
the patch antenna with a MOS capacitor. Theoretical investigations have been carried out for the MOS
capacitor loaded Annular Ring microstrip antenna, for oxide thicknesses from 100 A to 500 A, to predict
the achievable range of operational bandwidth. In spite of numerous advantages, the simple patch antenna
has a low operational bandwidth, which limits its applicability. Hence this technique of MOS capacitor
loaded Annular Ring microstrip patch antenna is to improve the operating frequency range.
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 discusses several rules and techniques of photography including:
1. The rule of thirds, which divides the frame into thirds both horizontally and vertically to place the subject near the intersection points.
2. Framing focuses the viewer's attention by using elements like windows, doors, or natural frames.
3. Leading lines guide the eye through the photograph from the front to the back along lines like paths, roads, or edges.
4. Balancing elements creates interest by placing the main subject off-center and filling empty space with other objects.
The document discusses edits made to photographs from a horror Alice in Wonderland photoshoot. It includes the original photographs alongside the edited versions. Edits include changing images to black and white, adding filters to alter colors, increasing contrast and brightness, adding special effects like snow, cutting out and combining elements between images, and adjusting depth of field. The photographer discusses which edits they prefer and how the edits help achieve different looks like fantasy, sunrise, or lost in the woods themes.
The document describes editing a photograph in several steps: applying a poster edges filter and adjusting its settings, applying a sumi-e filter and increasing exposure, desaturating the photo and adjusting brightness and contrast, and using the history brush tool to add color around the subject with a smaller brush size. The author notes they were experimenting with background colors and likes how the flowers look in purple rather than green.
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Experimental Study of an Atmospheric Pressure Dielectric Barrier Discharge an...IJERA Editor
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Горбунов Н.А., Государственная морская академия им. С.О. Макарова, г. Санкт-Петербург
Разработка плазменных технологий для прямого фотоэлектрического преобразования с сфокусированного солнечного излучения
1. ORIGINAL ARTICLE
Design and construction of prototype transversely
excited atmospheric (TEA) nitrogen laser energized
by a high voltage electrical discharge
Mukhtar Hussain *, Tayyab Imran
Dept. of Physics & Astronomy, College of Science, King Saud University, P.O. 2454, Riyadh 11541, Saudi Arabia
Received 6 February 2015; accepted 25 February 2015
Available online 5 March 2015
KEYWORDS
Laser;
Nitrogen laser;
TEA nitrogen laser;
High voltage power supply
Abstract The present study reports design and construction, of a prototype of Transversely
Excited Atmospheric (TEA) nitrogen laser, and a high voltage power supply to excite N2 gas in
air, while air is used as an active lasing medium. A Blumlein line discharge circuit is used for opera-
tion of this laser. The high voltage is generated by a fly back transformer based power supply vary-
ing from 10 kV to 20 kV. The wavelength (337.1 nm) of TEA nitrogen laser is measured employing
a standard commercial spectrometer and the laser output energy of 300 lJ is measured from the
constructed system. Different parameters such as beam profile, laser output spectrum, laser efficien-
cy, and variation of E/P (Electrical field/Pressure) value with respect to input voltage and electrodes
separations are studied in order to optimize the overall operational efficiency of present nitrogen
laser. The analysis of the high voltage prototype appeared in this designed source has also been
made and described in this paper.
ª 2015 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University. This is an
open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
1. Introduction
A Transversely Excited Atmospheric (TEA) nitrogen laser is a
pulse mode molecular gas laser. In this arrangement, the whole
volume of the gas is excited with a single electric pulse (Silfvast,
1996). Normally, N2 gas or air is being used as an active
medium in TEA nitrogen laser and lasing is obtained through
electrical discharge of N2 gas or air between two specifically
designed electrodes (Herden, 1975). A high potential difference
has been obtained by an ignition system in the laser discharge
channel creates a high electric field in the laser discharge chan-
nel which excites the nitrogen molecules due to fast pumping
mechanism from the ground state to the Upper laser level
C3
Pu Population inversion has created between the upper laser
level C3
Pu and the lower laser level B3
Pg by electron
impact excitations. The laser transition occurs by emitting
photons in ultraviolet (UV) region corresponding to the
C3
Pu fi B3
Pg transitions. The cross section for the electron
impact excitations from the ground state to the upper laser
level N2 (C3
Pu) and lower laser level N2 (B3
Pg), for the gain
coefficients had been introduced and experimentally examined
(Sarikhani and Hariri, 2010). The operation of nitrogen laser
* Corresponding author.
E-mail address: mukhussain@ksu.edu.sa (M. Hussain).
Peer review under responsibility of King Saud University.
Production and hosting by Elsevier
Journal of King Saud University – Science (2015) 27, 233–238
King Saud University
Journal of King Saud University –
Science
www.ksu.edu.sa
www.sciencedirect.com
http://dx.doi.org/10.1016/j.jksus.2015.02.008
1018-3647 ª 2015 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University.
This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
2. depends on a number of parameters and prerequisites like the
applied voltage, spark gap, rate of gas flow, electric field to
pressure ratio i.e. E/P, type of pre-ionization, length of active
medium, inductance, laser discharge channel geometry and
capacitances of capacitors. Since its birth many distinct fea-
tures of nitrogen laser have been reported, including: pulse
width, power output, effects of input power and gas flow
mechanism, spectrum examination and measurement of out-
put energies, spot size, electrode configuration, electrode spac-
ing, spark gap properties, the ratio of C1/C2 capacitance of
capacitors used in the Blumlein circuit, population inversion,
lasing material, gain coefficient, output energy characteristics
and fluorescence (Von Bergmann and Hasson, 1978;
Va´ zquezmartı´nez and Aboites, 1993).
The first nitrogen laser operation was reported by Heard
(1963), and the transversely excited atmospheric (TEA) nitro-
gen laser was introduced by Leonard (1965). Shipman (1967)
used a parallel plate transmission line for transversely excita-
tion of air. Generally, TEA nitrogen lasers operated at voltage
in the ranges of 5–40 kV with the output energies from 40 to
370 lJ (Bergmann, 1977; Hasson et al., 1976; Santa et al.,
1986; Schmidt et al., 1975; Suchard et al., 1975). Later, a
miniature type of TEA nitrogen laser was also introduced
employing 3 cm silicon electrodes operating at 5 kV and pulse
energy of few lJ (Meisel and Langhoff, 1996). Recently, the
inductive energy storage with the increased output energy
per pulse was reported by Panchenko et al. (2009).
TEA nitrogen laser is a source of pulse light and it has been
used to measure the speed of sound in different materials, to
visualize the pulse plasma in nanosecond range was observed
by Averin et al. (2004), applications in medicine (Provorov
et al., 2005), determination of estrogens using surface assisted
laser desorption (Chiu et al., 2008), nano particles based mass
spectrometry for biomolecules analysis reported Chiang et al.
(2011), deposition of thin films for nonlinear optical applica-
tions by El Ouazzani et al. (2012), characterization of phase
change chalcogenide thin films (Alvi et al., 2013),
crystallization of Te doped Ge–Se thin films has been done
by Al-Agel (2014) with TEA nitrogen laser.
Here, we report a prototype TEA nitrogen laser design and
a high voltage power supply to generate electrical discharge in
air. The power source is based on flyback transformer with
output voltage varying from 10 to 20 kV. In the present work,
the TEA nitrogen laser electrodes are set to be used for travel-
ing wave excitation in the transverse mode of operation. The
transverse arrangement of electrodes has given preference over
the longitudinal arrangement because of delivering high output
power, efficient and faster voltage rise time. A free running
spark gap (SG) has used for the triggering of the laser system
that transfers the electrical energy into the laser channel, which
excites the air molecules in a time scale of few nanosecond. We
achieved the corona surface discharge by inserting a dielectric
material between capacitor plates, keeping uniform gap
between parallel plate capacitors and obtained a uniform glow
discharge by clamping electrodes on the plates of capacitors
just 2 mm at the height above the corona surface discharge.
This design for the corona distance is considerably lower com-
pared to designs reported earlier (Hariri et al., 1990; Sarikhani
and Hariri, 2013).
2. Methods and materials
2.1. Design, construction and working of TEA N2 laser
The present TEA nitrogen laser design has based on Blumlein
line discharge circuit as shown in Fig. 1, which is used to excite
air within few nanoseconds in the laser discharge channel. In
Fig. 2, the equivalent circuit of Blumlein design has shown.
The present design consists of two parallel plate capacitors,
C1 and C2 located on both sides of the laser discharge channel
and connected through an inductor L. Both capacitors are
charged and ignited through a spark gap which has connected
to a high voltage power supply and C1 capacitor. One end of
Figure 1 Schematic setup of TEA nitrogen laser.
234 M. Hussain, T. Imran
3. the spark gap has connected to one of the capacitor plate (C1)
and other end to the common plate. As the spark gap has ignit-
ed, a traveling wave has been setup in one of the transmission
lines, and gas discharge has started where it produces another
traveling wave in the second electrodes. These two traveling
waves superimpose and produce a high voltage which main-
tains the discharge in the laser discharge channel. To obtain
a uniform discharge in the laser discharge channel, the impe-
dance of the excitation system should be minimized. The impe-
dance Z of the transmission line had been introduced (Crouch
and Risk, 1972).
Z ¼
337
ffiffiffiffi
er
p
d
ðd þ wÞ
ð1Þ
We used the material with the dielectric constant ðerÞ of
2.26, d is the separation between transmissions lines
0.1 mm, and w is width of the transmission line which is
34.0 cm. The impedance of the transmission line should be
very low to obtain a uniform glow discharge in the laser dis-
charge channel. The calculated value of the impedance of the
transmission line is 0.067 O. The experimental setup has been
divided into four parts, they are: capacitors, inductor, a spark
gap and electrodes.
A transparency sheet of thickness 0.1 mm has sandwiched
between the aluminum foil and two aluminum sheets of areas
754 cm2
and 606.97 cm2
. This transparency sheet acts as a
dielectric material with the dielectric constant er of 2.26. This
arrangement of aluminum sheets forms the parallel combina-
tion of two capacitors C1 and C2, whereas the capacitances
of these capacitors are 15.08 nF and 12.14 nF, respectively.
With this arrangement the total capacitance of this combina-
tion is 27.22 nF. Two aluminum electrodes are connected with
the capacitors C1 and C2 and the space between the electrodes
forms the laser discharge channel which has been designed in
such a way to tolerate the effect of heating, high voltage and
high peak current and ultraviolet radiations. The edges of
the electrodes are aligned up to micrometer levels to get uni-
form discharge at atmospheric gas pressure. The gap separa-
tions between the electrodes at the back and front ends of
laser discharge channel have been set to 1.4 mm and 1.5 mm,
respectively to obtain uniform glow discharge in the laser
discharge channel.
The two electrodes are connected with each other through
an inductor L of length 9 cm having 32 turns with 2.35 cm
of diameter. The inductance of this inductor is 5.58 lH, where
it offers a low resistance for obtaining a fast electric discharge.
The free running spark gap consists of two adjustable brass
screws that are connected to capacitor C1. Both capacitors
are charged simultaneously through an inductor L with proto-
type constructed high voltage power supply. When the applied
voltage reaches to a level for the gas breakdown, the spark gap
fires, the capacitor C1 discharges fully while the inductor
imposes a high resistance to the rapidly changed voltage and
does not allow the current to flow through inductor which
keeps the capacitor C2 to stay in a highly charged state.
Because of high voltage power supply, a high potential
difference has developed between the electrodes which gener-
ate high electric field between two electrodes.
A rapid discharge occurs in air in the laser discharge chan-
nel because of the high electric field where it consequently leads
to lasing in the UV regime. High voltage power supply has
been used as a pump source for constructed TEA nitrogen
laser and the free running spark gap has used as a triggering
switch which shorts the circuit. The separation between the
spark gap electrodes can be adjusted between 2 and 4 mm. If
the gap of the spark gap is adjusted too large, the limit of stor-
age voltage has exceeded the breakdown voltage of dielectric
material and system fails to perform. If the gap is kept too
small, then, the proper excitation of air molecules does not
happen. Therefore, lasing cannot be achieved in this case.
Figure 2 Equivalent Blumlein discharge circuit.
Figure 3 Circuit diagram of high voltage power supply.
Prototype transversely excited atmospheric (TEA) nitrogen laser 235
4. The most efficient lasing operation has been observed for a
3 mm gap of the spark gap for the reported system.
2.2. High voltage power supply
The circuit diagram of the high voltage power supply used in
the present work is shown in Fig. 3. The design of the high
voltage power supply consists of three stages, bridge rectifier
and filter circuit to provide the +12 V dc voltage to operate
timer circuit and the flyback transformer driver which is based
on MOSFET.
The conventional bridge rectifier circuit consists of four sili-
con diodes to convert the alternating current to direct current,
and the capacitor has been used as a filter for smoothing the
direct current pulse waveform. This circuit should be able to
provide +12 V dc at about 3 A. Major electronic components
in the driver circuit are LM555CM, 2N2222 transistor,
MOSFET IRF 540 along with the potentiometers, capacitor
and resistances. C is the capacitance of the capacitor, which
is 0.01 lF and l are potentiometers whose values can be varied
from 1 to 10 kO.
3. Results and discussion
The frequency variation along LM555CM and MOSFET has
been adjusted to obtain the required high voltage from the
constructed prototype high voltage power supply. The output
frequencies from LM555CM and MOSFET are dependent on
resistance, when we adjust the values of R1 and R2 to 1.10 kX
and 3.2 kX, respectively. The calculated output frequency of
LM555CM is 19.23 kHz which is in a good agreement with
the measured value, as shown in Fig. 4(a).
The timer circuit has used LM555CM to pulse a transistor
2N2222 with a square wave at a frequency that has been set by
Figure 4 (a) Frequency output of LM555CM. (b) Frequency output of MOSFET.
236 M. Hussain, T. Imran
5. the potentiometers R1 and R2. The transistor 2N2222, then,
drives the gate of the MOSFET and the MOSFET delivers
the pulse to the flyback transformer and ultimately high output
voltage obtained across the secondary of the flyback trans-
former. We adjusted the potentiometers to achieve the highest
possible voltage i.e. (10–20)kV. The output frequency from the
LM555CM and MOSFET are well captured by a digital oscil-
loscope as shown in Fig. 4(b). It can be seen the pulse ampli-
tude after the MOSFET decreased four time, but the
frequency remains the same as generated by the LM555CM.
The output spectrum of laser beam has been measured by a
standard spectrometer (Avantes, Inc.). The spectrum of the
prototype TEA nitrogen laser system has shown in Fig. 5,
which confirms that the peak wavelength of nitrogen laser
occurs at 337.14 nm, and the full width at half maximum of
the spectrum in this measurement has measured 1.0207 nm.
The output beam profile of nitrogen laser has shown in
Fig. 6. The beam spot is significant and produces more fluores-
cence if it has exposed to a white paper.
To analyze the efficiency of the nitrogen laser, relations
between the different parameters are studied. These para-
meters are: applied voltage, electric field between the electrodes
in the laser discharge channel, and the gap separation in the
spark gap. When the input voltage has set to 10 kV, with the
electrodes separation adjusted to 1.4 mm, the calculated E/P
value is 132.518 V/(cm.torr), while at 1.5 mm electrode separa-
tion the E/P value has been calculated 123.684 V/(cm.torr).
The E/P value which is related to electron temperature Te
(Sarikhani and Hariri, 2013) increases when the electrode
separation decreases and also when the input voltage increases.
The output pulse energy of 300 lJ has measured in the UV
range at 337.1 nm. It has been observed that the peak power
of this prototype TEA nitrogen laser increases with the
increase of input voltage.
4. Conclusion
In this work, a TEA nitrogen laser of prototype has been
designed and constructed based on Blumlein line discharge cir-
cuit and air in the laser discharge channel has been excited by a
prototype constructed high voltage power supply. A uniform
glow discharge has been achieved at considerably lower height
above the surface corona discharge compared to the earlier
reports. To optimize the efficiency of the TEA nitrogen laser,
other parameters such as variation of the output power with
respect to the input voltage, change of efficiency with the input
voltage and the variation of E/P with the input voltage have
been studied at different electrodes separations. Our observed
and measured results of the present prototype TEA nitrogen
laser has very much comparable to the published data of
TEA nitrogen lasers.
Acknowledgments
The authors acknowledge this research was carried out at
SBASSE-LUMS, Lahore, Pakistan. The authors would also
like to greatly acknowledge the support of Dr. Muhammad
Sabieh Anwar, Chairman Physics Department at SBASSE-
LUMS, Pakistan.
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