How a medical cyclotron works by emmanuel w. fiagbedzi
•Download as PPT, PDF•
8 likes•1,626 views
A cyclotron is a type of particle accelerator that uses electric and magnetic fields to accelerate charged particles in a spiral path. It consists of two "D"-shaped electrodes called "dees" located between the poles of a magnet. As the polarity of the electric field alternates between the dees, particles gain kinetic energy on each orbit until they are ejected at high speeds. Cyclotrons are commonly used to produce radioactive isotopes for medical imaging and diagnosis.
Report
Share
Report
Share
Recommended
The Cyclotron
The cyclotron was invented by Leo Szilard in the 1920s and was a particle accelerator that influenced scientific research. It works by accelerating charged particles in a spiral path within magnetic fields, gaining more speed and energy with each turn. Cyclotrons were important for producing radioactive isotopes used in medical imaging technologies like PET and for experiments in nuclear and particle physics. They had advantages over previous accelerators but also limitations in the size of particles they could accelerate. Cyclotrons played a key role in scientific discoveries and the development of nuclear medicine.
Cyclotron
The document summarizes the cyclotron, which accelerates charged particles. It was invented in 1934 by Lawrence and Livingston. A cyclotron uses a magnetic field to bend charged particles into a circular path between two "dees" where an alternating electric field accelerates the particles on each half-circle. As the particles' velocity and radius increase with each pass between the dees, their kinetic energy also increases until they exit the cyclotron. The cyclotron is still used today as the first stage of some large particle accelerators to produce very high energy particles for nuclear physics experiments requiring high-energy collisions.
PET Cyclotron
Cyclotrons are particle accelerators that use magnetic and electric fields to accelerate charged particles in a circular path. They are commonly used to produce short-lived radionuclides for positron emission tomography by bombarding target materials with protons or deuterons. Key components of a cyclotron include ion sources, dees, magnetic fields, radiofrequency systems, and targets.
Cyclotron
- Cyclotrons use magnetic and electric fields to accelerate charged particles in a circular path, increasing their energy each time they pass through the accelerating field. Ernest Lawrence invented the cyclotron in the 1930s.
- Cyclotrons consist of two semicircular electrodes called dees placed between the poles of a magnet. Charged particles are accelerated as they spiral between the dees due to alternating electric fields.
- Cyclotrons are used to accelerate protons and ions for applications such as nuclear physics experiments and particle therapy for cancer treatment. They can also produce short-lived radioactive isotopes used in PET imaging. However, maintaining uniform magnetic fields over large areas is challenging for cyclotrons.
Cyclotron
This document describes the working of a cyclotron particle accelerator. It explains that a cyclotron uses a magnetic field to curve the path of charged particles into a circular orbit, while an alternating electric field accelerates the particles at each half orbit. As the particles accelerate, they travel along spiraling paths of increasing radius. The document provides details on the construction of a cyclotron, including its dees and vacuum chamber between magnets. It also gives the mathematical expression for the cyclotron frequency that determines the electric field frequency needed for resonance acceleration. Limitations of the cyclotron are that particle mass may change at high speeds and it is difficult to accelerate low-mass particles like electrons.
Cyclotron
The document summarizes key aspects of a cyclotron, which is a device that accelerates charged particles outwards in a spiral path using crossed electric and magnetic fields. It was invented in 1929 and the first operational cyclotron was built in 1932 by Ernest Lawrence. Cyclotrons work by subjecting particles to an oscillating electric field while they travel in a circle due to a static magnetic field. Modifications allow relativistic speeds. Cyclotrons are used in nuclear physics experiments and for producing isotopes for PET imaging and particle cancer therapy. Limitations include inability to accelerate neutral particles or electrons.
Linac presentation
This document discusses the key components and operating principles of a linear accelerator (linac) system. It describes how linacs use resonant cavities and radio frequency waves to gradually accelerate electrons to high energies. The document outlines the main subsystems of a linac including the electron gun, accelerating structure, beam transport system, flattening filters, collimators, and dose monitoring ionization chambers. It also explains how different components like the magnetron, klystron, and pulse modulator are used to generate and synchronize the radio frequency waves needed for particle acceleration.
Linear accelerator
Medical linear accelerator with telecobalt source head
Include:basic principle,history,working,constructions
Recommended
The Cyclotron
The cyclotron was invented by Leo Szilard in the 1920s and was a particle accelerator that influenced scientific research. It works by accelerating charged particles in a spiral path within magnetic fields, gaining more speed and energy with each turn. Cyclotrons were important for producing radioactive isotopes used in medical imaging technologies like PET and for experiments in nuclear and particle physics. They had advantages over previous accelerators but also limitations in the size of particles they could accelerate. Cyclotrons played a key role in scientific discoveries and the development of nuclear medicine.
Cyclotron
The document summarizes the cyclotron, which accelerates charged particles. It was invented in 1934 by Lawrence and Livingston. A cyclotron uses a magnetic field to bend charged particles into a circular path between two "dees" where an alternating electric field accelerates the particles on each half-circle. As the particles' velocity and radius increase with each pass between the dees, their kinetic energy also increases until they exit the cyclotron. The cyclotron is still used today as the first stage of some large particle accelerators to produce very high energy particles for nuclear physics experiments requiring high-energy collisions.
PET Cyclotron
Cyclotrons are particle accelerators that use magnetic and electric fields to accelerate charged particles in a circular path. They are commonly used to produce short-lived radionuclides for positron emission tomography by bombarding target materials with protons or deuterons. Key components of a cyclotron include ion sources, dees, magnetic fields, radiofrequency systems, and targets.
Cyclotron
- Cyclotrons use magnetic and electric fields to accelerate charged particles in a circular path, increasing their energy each time they pass through the accelerating field. Ernest Lawrence invented the cyclotron in the 1930s.
- Cyclotrons consist of two semicircular electrodes called dees placed between the poles of a magnet. Charged particles are accelerated as they spiral between the dees due to alternating electric fields.
- Cyclotrons are used to accelerate protons and ions for applications such as nuclear physics experiments and particle therapy for cancer treatment. They can also produce short-lived radioactive isotopes used in PET imaging. However, maintaining uniform magnetic fields over large areas is challenging for cyclotrons.
Cyclotron
This document describes the working of a cyclotron particle accelerator. It explains that a cyclotron uses a magnetic field to curve the path of charged particles into a circular orbit, while an alternating electric field accelerates the particles at each half orbit. As the particles accelerate, they travel along spiraling paths of increasing radius. The document provides details on the construction of a cyclotron, including its dees and vacuum chamber between magnets. It also gives the mathematical expression for the cyclotron frequency that determines the electric field frequency needed for resonance acceleration. Limitations of the cyclotron are that particle mass may change at high speeds and it is difficult to accelerate low-mass particles like electrons.
Cyclotron
The document summarizes key aspects of a cyclotron, which is a device that accelerates charged particles outwards in a spiral path using crossed electric and magnetic fields. It was invented in 1929 and the first operational cyclotron was built in 1932 by Ernest Lawrence. Cyclotrons work by subjecting particles to an oscillating electric field while they travel in a circle due to a static magnetic field. Modifications allow relativistic speeds. Cyclotrons are used in nuclear physics experiments and for producing isotopes for PET imaging and particle cancer therapy. Limitations include inability to accelerate neutral particles or electrons.
Linac presentation
This document discusses the key components and operating principles of a linear accelerator (linac) system. It describes how linacs use resonant cavities and radio frequency waves to gradually accelerate electrons to high energies. The document outlines the main subsystems of a linac including the electron gun, accelerating structure, beam transport system, flattening filters, collimators, and dose monitoring ionization chambers. It also explains how different components like the magnetron, klystron, and pulse modulator are used to generate and synchronize the radio frequency waves needed for particle acceleration.
Linear accelerator
Medical linear accelerator with telecobalt source head
Include:basic principle,history,working,constructions
Cyclotron presentation
This document discusses the cyclotron, a type of particle accelerator. It begins with an introduction and overview of key topics like principles, construction, diagrams, workings, calculations, applications, and limitations. Some key points made are:
- A cyclotron accelerates charged particles like protons and deuterons using electric and magnetic fields, generating energies from 1 MeV to over 100 MeV.
- It works on the principle that a charged particle moving perpendicular to a magnetic field experiences a force causing it to travel in a circular path, with increasing radius and velocity over time due to an oscillating electric field.
- Important applications of cyclotrons include production of beams for nuclear physics experiments and cancer particle therapy.
Basic of medical linac
The document summarizes a medical linear accelerator (LINAC). It describes how a LINAC works by using high-frequency electromagnetic waves to accelerate electrons and produce x-rays. It then discusses the history and development of LINACs from the first installation in 1952 to modern machines. Key components of a LINAC are also outlined, including the electron gun, magnetron/klystron, waveguide, and treatment head.
Computed Tomography Dose Index
Computed Tomography Dose Index, Includes various CTDI parameters and the way of calculating effective dose from various Computed Tomography procedures along with their conversion factor.
Radionuclide Production - Nuclear Medicine
This document discusses different methods of radionuclide production, including reactors, cyclotrons, and generators. Reactors produce radionuclides like 90Sr, 99Mo, 131I, and 133Xe through fission of uranium or plutonium fuel rods. Cyclotrons bombard stable nuclei with particles like protons or alpha particles to produce radionuclides. Common generators include the 99mTc generator, which extracts 99mTc from its 99Mo parent with half lives of 67 hours and 6 hours respectively, and the 81Rb/81Kr generator, which uses a membrane to extract the short-lived 81Kr daughter from its 81Rb parent with half lives of 4.
Medical Physics Group 4.pdf
The cyclotron is a device that accelerates charged particles using crossed electric and magnetic fields. It was invented in 1929 by Ernest Lawrence and consists of two hollow metal electrodes called dees placed between the poles of a magnet. Charged particles injected into the dees spiral outward due to the magnetic field while being accelerated by a rapidly alternating electric field. Cyclotrons are used for nuclear experiments and particle therapy for cancer treatment by accelerating beams to high energies.
Cyclotron
The document summarizes the cyclotron, which accelerates charged particles. It describes how the cyclotron works using magnetic and electric fields to accelerate particles in a spiral path between two "dees". As the particles' velocity and radius increase with each turn, their kinetic energy also increases. However, the cyclotron cannot accelerate electrons or neutrons due to their small mass and lack of charge, respectively. The maximum energy particles attain depends on the radius of the dees. Cyclotrons are still used to produce high-energy particles for nuclear physics experiments requiring high-energy collisions.
Cyclotron (1)
Cyclotrons accelerate charged particles using oscillating electric fields generated between hollow metal chambers called dees. A positive ion is placed between the dees and accelerated toward the first dee when it is negatively charged. It follows a semicircular path due to a strong magnetic field until the dee polarities are reversed, accelerating it toward the second dee and to higher energies with each pass through the oscillating field. Cyclotrons can be used to accelerate ion beams for nuclear physics experiments and cancer treatment through proton therapy.
X rays generators and transformers
X-ray generators are used to power x-ray tubes in radiology. They contain transformers, diodes, and circuits to select energy, quantity, and exposure time. Generators can be single-phase, three-phase, constant potential, or high-frequency. Three-phase generators provide a continuous output to reduce exposure time and improve image quality. Constant potential generators produce a near-DC waveform for more efficient acceleration of electrons.
Physics in Nuclear Medicine
This document provides an overview of physics concepts related to nuclear medicine, including radioactive decay and various modes of decay. It discusses:
- Radioactive decay results from nuclear instability and transforms an unstable nucleus into a more stable daughter nucleus through emission of particles/photons.
- Common modes of decay include beta emission, in which a neutron transforms to a proton and electron/neutrino, and alpha/beta-gamma emission, where decay to an excited daughter state is followed by gamma emission.
- Properties like decay mode, transition energy, and lifetime are characteristic of each radionuclide. Radioactive and chemical properties are generally independent.
spect and pet
This document discusses SPECT and PET imaging. It explains that radionuclides are produced artificially and decay via processes like beta decay, producing gamma rays. SPECT uses gamma camera systems to produce 3D functional images, and is affected by factors like photon attenuation. PET involves injecting a radiolabeled tracer like FDG and detecting coincident gamma rays to locate the tracer distribution. Common clinical applications of SPECT and PET imaging include evaluating glucose metabolism in neurology, cardiology and oncology.
Interaction of radiation with matter
The document discusses the interaction of radiation with matter. It describes different types of interactions including the photoelectric effect, Compton scattering, and pair production. These interactions vary based on the photon energy and atomic number of the absorbing material. The photoelectric effect is more likely for low energy photons and high atomic number materials. Compton scattering does not depend on atomic number. Pair production requires the highest minimum photon energy and is more likely for high atomic number materials. The document also discusses attenuation coefficients and how they relate to the probability of each interaction type.
radIATION UNITS
This document discusses various radiation quantities and units used to characterize ionizing radiation. It describes key concepts such as activity, kerma, exposure, absorbed dose, equivalent dose, effective dose, annual limit intake (ALI), and derived air concentration (DAC). The International Commission on Radiation Protection (ICRP) and International Commission on Radiation Units (ICRU) help define these quantities and their relationships. Primary quantities like equivalent dose relate radiation risk, while operational quantities like exposure are used for measurements. Tissue weighting factors account for different tissue sensitivities in calculating effective dose from equivalent dose.
Cyclotron accelerator
cyclotron that accelerate the charge particles prior their bombardment to the target nuclei.
it is developed by E.O.Lawrence & he was awarded by nobel prize in this work. it accelerate the particle from 1MeV to the more than 100 MeV.
it contains the electric & magnetic system to accelerate the charge particles.
electric field acts horizontally & magnetic field act vertically.
particle moves in spiral path and its energy , radius & velocity increases.
after that it moves out of window ( diflactor plate) n hit the target.
n then the nuclear reaction starts.
it is used to treat cancer.
produce positrons emission isotopes for PET imaging.
it do not accelerate the neutrons, electrons & positive charge with higher mass.
The Physics of MRI
A brief presentation on The Physics of MRI by Nilotpal Das, proudly presented by Biomedicz (www.biomedicz.com)
Linear accelerator vinay
The document summarizes a medical linear accelerator (LINAC). Key points:
- LINAC uses high-frequency waves to accelerate electrons which are used to treat tumors through electron beams or x-ray beams produced by electron impacts on a target.
- Early LINACs from the 1950s-1980s were large, bulky, and had limited motion. Modern LINACs have improved acceleration, more treatment options, and greater reliability.
- LINAC consists of an electron gun, microwave generator, waveguide, treatment head with collimation/target, monitoring devices, and safety systems. It accelerates electrons to treat cancer through precise x-ray beams.
Betatron ppt
A betatron is a device that accelerates electrons using an expanding magnetic field within a doughnut-shaped vacuum chamber. Electrons are injected into the chamber and accelerated as the magnetic field strength increases over time. This increasing magnetic flux induces an electric field that increases the electrons' energy, allowing them to gain extremely high speeds. The betatron condition requires that the rate of change of magnetic flux through the circular orbit equals 2π times the radius squared times the rate of change of the magnetic field, in order to maintain the electrons' constant orbital radius as they accelerate.
Mri hardware
MRI machines use magnetic fields, radio waves, and computers to detect properties of living tissue. The first MRI image of the human body was obtained in 1977 and detected cancer tissue. MRI requires a magnet to align nuclear spins, radio waves to excite the spins, magnetic field gradients for spatial encoding, and a computer system to form images. Stronger magnetic fields allow for higher resolution images. Electromagnets, resistive magnets, superconducting magnets, and permanent magnets can be used to generate magnetic fields, with superconducting magnets allowing the highest field strengths. Radiofrequency coils transmit the excitation signal and receive the emitted signal used to form images.
Linear Accelerators
Linear accelerators (linacs) are used to generate high energy x-ray and electron beams for radiation therapy. A linac consists of an electron gun, radiofrequency power source, accelerating waveguide, beam transport system, and treatment head. Electrons are generated and accelerated to megavoltage energies using microwave fields in the waveguide. The accelerated electron beam is transported and bent using magnets to strike a target and produce x-rays, or exit directly as an electron beam. The treatment head houses the target, flattening filter, collimators, and monitors to shape the beam for patient treatment. Modern linacs provide flexible photon and electron beams with variable energies for radiation therapy.
Physics and Operation of Linear Accelerator
The document provides information on the physics and operation of medical linear accelerators. It discusses the history and development of linear accelerators from 1st to 5th generation machines. The key components of a modern linac are described, including the electron injection system, RF power generation using klystrons or magnetrons, the accelerating waveguide, electron beam transport using bending magnets, and beam collimation and monitoring systems using components like flattening filters, ionization chambers, and multileaf collimators. Modern linacs can accelerate electrons to energies over 20 MeV and are able to treat deep-seated tumors with high precision using computer-controlled systems.
CHAPTER-7 - QUALITY OF X-RAY BEAM
1. The quality of an x-ray beam is often described by its penetrating ability and can be specified by measuring parameters like the half-value layer (HVL) and peak kilovoltage (kVp).
2. Filters are used to selectively attenuate low energy rays and alter the beam's spectral distribution. Common filters include aluminum, copper, and flattening filters.
3. The HVL, kVp, and added filtration together characterize low energy x-ray beams, while megavoltage beams are typically specified by their peak energy.
CHARGE PARTICLE ACCELERATORCharge particle accelerator
A particle accelerator is a device that increases the kinetic energy of electrically charged particles through the use of electric and magnetic fields. The cyclotron, invented in 1931, is an early type of particle accelerator that uses a high frequency oscillator to accelerate positively charged particles in a spiral path between two "D-shaped" electrodes placed in a strong magnetic field. As the particles accelerate, they travel in larger circular paths until they exit and can be used for nuclear reaction experiments or medical treatments like cancer therapy.
Cyclotron (1)
Cyclotrons accelerate charged particles using oscillating electric fields generated between hollow metal chambers called dees. A positive ion is placed between the dees and accelerated toward the first dee when it is negatively charged. The magnetic field causes the ion to travel in a semicircular path, and it is accelerated again when the dee polarities reverse just as the ion reaches the gap. This process continues to accelerate the ion with each pass. Cyclotrons can be used to accelerate proton beams for nuclear physics experiments and cancer treatment through proton therapy.
More Related Content
What's hot
Cyclotron presentation
This document discusses the cyclotron, a type of particle accelerator. It begins with an introduction and overview of key topics like principles, construction, diagrams, workings, calculations, applications, and limitations. Some key points made are:
- A cyclotron accelerates charged particles like protons and deuterons using electric and magnetic fields, generating energies from 1 MeV to over 100 MeV.
- It works on the principle that a charged particle moving perpendicular to a magnetic field experiences a force causing it to travel in a circular path, with increasing radius and velocity over time due to an oscillating electric field.
- Important applications of cyclotrons include production of beams for nuclear physics experiments and cancer particle therapy.
Basic of medical linac
The document summarizes a medical linear accelerator (LINAC). It describes how a LINAC works by using high-frequency electromagnetic waves to accelerate electrons and produce x-rays. It then discusses the history and development of LINACs from the first installation in 1952 to modern machines. Key components of a LINAC are also outlined, including the electron gun, magnetron/klystron, waveguide, and treatment head.
Computed Tomography Dose Index
Computed Tomography Dose Index, Includes various CTDI parameters and the way of calculating effective dose from various Computed Tomography procedures along with their conversion factor.
Radionuclide Production - Nuclear Medicine
This document discusses different methods of radionuclide production, including reactors, cyclotrons, and generators. Reactors produce radionuclides like 90Sr, 99Mo, 131I, and 133Xe through fission of uranium or plutonium fuel rods. Cyclotrons bombard stable nuclei with particles like protons or alpha particles to produce radionuclides. Common generators include the 99mTc generator, which extracts 99mTc from its 99Mo parent with half lives of 67 hours and 6 hours respectively, and the 81Rb/81Kr generator, which uses a membrane to extract the short-lived 81Kr daughter from its 81Rb parent with half lives of 4.
Medical Physics Group 4.pdf
The cyclotron is a device that accelerates charged particles using crossed electric and magnetic fields. It was invented in 1929 by Ernest Lawrence and consists of two hollow metal electrodes called dees placed between the poles of a magnet. Charged particles injected into the dees spiral outward due to the magnetic field while being accelerated by a rapidly alternating electric field. Cyclotrons are used for nuclear experiments and particle therapy for cancer treatment by accelerating beams to high energies.
Cyclotron
The document summarizes the cyclotron, which accelerates charged particles. It describes how the cyclotron works using magnetic and electric fields to accelerate particles in a spiral path between two "dees". As the particles' velocity and radius increase with each turn, their kinetic energy also increases. However, the cyclotron cannot accelerate electrons or neutrons due to their small mass and lack of charge, respectively. The maximum energy particles attain depends on the radius of the dees. Cyclotrons are still used to produce high-energy particles for nuclear physics experiments requiring high-energy collisions.
Cyclotron (1)
Cyclotrons accelerate charged particles using oscillating electric fields generated between hollow metal chambers called dees. A positive ion is placed between the dees and accelerated toward the first dee when it is negatively charged. It follows a semicircular path due to a strong magnetic field until the dee polarities are reversed, accelerating it toward the second dee and to higher energies with each pass through the oscillating field. Cyclotrons can be used to accelerate ion beams for nuclear physics experiments and cancer treatment through proton therapy.
X rays generators and transformers
X-ray generators are used to power x-ray tubes in radiology. They contain transformers, diodes, and circuits to select energy, quantity, and exposure time. Generators can be single-phase, three-phase, constant potential, or high-frequency. Three-phase generators provide a continuous output to reduce exposure time and improve image quality. Constant potential generators produce a near-DC waveform for more efficient acceleration of electrons.
Physics in Nuclear Medicine
This document provides an overview of physics concepts related to nuclear medicine, including radioactive decay and various modes of decay. It discusses:
- Radioactive decay results from nuclear instability and transforms an unstable nucleus into a more stable daughter nucleus through emission of particles/photons.
- Common modes of decay include beta emission, in which a neutron transforms to a proton and electron/neutrino, and alpha/beta-gamma emission, where decay to an excited daughter state is followed by gamma emission.
- Properties like decay mode, transition energy, and lifetime are characteristic of each radionuclide. Radioactive and chemical properties are generally independent.
spect and pet
This document discusses SPECT and PET imaging. It explains that radionuclides are produced artificially and decay via processes like beta decay, producing gamma rays. SPECT uses gamma camera systems to produce 3D functional images, and is affected by factors like photon attenuation. PET involves injecting a radiolabeled tracer like FDG and detecting coincident gamma rays to locate the tracer distribution. Common clinical applications of SPECT and PET imaging include evaluating glucose metabolism in neurology, cardiology and oncology.
Interaction of radiation with matter
The document discusses the interaction of radiation with matter. It describes different types of interactions including the photoelectric effect, Compton scattering, and pair production. These interactions vary based on the photon energy and atomic number of the absorbing material. The photoelectric effect is more likely for low energy photons and high atomic number materials. Compton scattering does not depend on atomic number. Pair production requires the highest minimum photon energy and is more likely for high atomic number materials. The document also discusses attenuation coefficients and how they relate to the probability of each interaction type.
radIATION UNITS
This document discusses various radiation quantities and units used to characterize ionizing radiation. It describes key concepts such as activity, kerma, exposure, absorbed dose, equivalent dose, effective dose, annual limit intake (ALI), and derived air concentration (DAC). The International Commission on Radiation Protection (ICRP) and International Commission on Radiation Units (ICRU) help define these quantities and their relationships. Primary quantities like equivalent dose relate radiation risk, while operational quantities like exposure are used for measurements. Tissue weighting factors account for different tissue sensitivities in calculating effective dose from equivalent dose.
Cyclotron accelerator
cyclotron that accelerate the charge particles prior their bombardment to the target nuclei.
it is developed by E.O.Lawrence & he was awarded by nobel prize in this work. it accelerate the particle from 1MeV to the more than 100 MeV.
it contains the electric & magnetic system to accelerate the charge particles.
electric field acts horizontally & magnetic field act vertically.
particle moves in spiral path and its energy , radius & velocity increases.
after that it moves out of window ( diflactor plate) n hit the target.
n then the nuclear reaction starts.
it is used to treat cancer.
produce positrons emission isotopes for PET imaging.
it do not accelerate the neutrons, electrons & positive charge with higher mass.
The Physics of MRI
A brief presentation on The Physics of MRI by Nilotpal Das, proudly presented by Biomedicz (www.biomedicz.com)
Linear accelerator vinay
The document summarizes a medical linear accelerator (LINAC). Key points:
- LINAC uses high-frequency waves to accelerate electrons which are used to treat tumors through electron beams or x-ray beams produced by electron impacts on a target.
- Early LINACs from the 1950s-1980s were large, bulky, and had limited motion. Modern LINACs have improved acceleration, more treatment options, and greater reliability.
- LINAC consists of an electron gun, microwave generator, waveguide, treatment head with collimation/target, monitoring devices, and safety systems. It accelerates electrons to treat cancer through precise x-ray beams.
Betatron ppt
A betatron is a device that accelerates electrons using an expanding magnetic field within a doughnut-shaped vacuum chamber. Electrons are injected into the chamber and accelerated as the magnetic field strength increases over time. This increasing magnetic flux induces an electric field that increases the electrons' energy, allowing them to gain extremely high speeds. The betatron condition requires that the rate of change of magnetic flux through the circular orbit equals 2π times the radius squared times the rate of change of the magnetic field, in order to maintain the electrons' constant orbital radius as they accelerate.
Mri hardware
MRI machines use magnetic fields, radio waves, and computers to detect properties of living tissue. The first MRI image of the human body was obtained in 1977 and detected cancer tissue. MRI requires a magnet to align nuclear spins, radio waves to excite the spins, magnetic field gradients for spatial encoding, and a computer system to form images. Stronger magnetic fields allow for higher resolution images. Electromagnets, resistive magnets, superconducting magnets, and permanent magnets can be used to generate magnetic fields, with superconducting magnets allowing the highest field strengths. Radiofrequency coils transmit the excitation signal and receive the emitted signal used to form images.
Linear Accelerators
Linear accelerators (linacs) are used to generate high energy x-ray and electron beams for radiation therapy. A linac consists of an electron gun, radiofrequency power source, accelerating waveguide, beam transport system, and treatment head. Electrons are generated and accelerated to megavoltage energies using microwave fields in the waveguide. The accelerated electron beam is transported and bent using magnets to strike a target and produce x-rays, or exit directly as an electron beam. The treatment head houses the target, flattening filter, collimators, and monitors to shape the beam for patient treatment. Modern linacs provide flexible photon and electron beams with variable energies for radiation therapy.
Physics and Operation of Linear Accelerator
The document provides information on the physics and operation of medical linear accelerators. It discusses the history and development of linear accelerators from 1st to 5th generation machines. The key components of a modern linac are described, including the electron injection system, RF power generation using klystrons or magnetrons, the accelerating waveguide, electron beam transport using bending magnets, and beam collimation and monitoring systems using components like flattening filters, ionization chambers, and multileaf collimators. Modern linacs can accelerate electrons to energies over 20 MeV and are able to treat deep-seated tumors with high precision using computer-controlled systems.
CHAPTER-7 - QUALITY OF X-RAY BEAM
1. The quality of an x-ray beam is often described by its penetrating ability and can be specified by measuring parameters like the half-value layer (HVL) and peak kilovoltage (kVp).
2. Filters are used to selectively attenuate low energy rays and alter the beam's spectral distribution. Common filters include aluminum, copper, and flattening filters.
3. The HVL, kVp, and added filtration together characterize low energy x-ray beams, while megavoltage beams are typically specified by their peak energy.
What's hot (20)
Similar to How a medical cyclotron works by emmanuel w. fiagbedzi
CHARGE PARTICLE ACCELERATORCharge particle accelerator
A particle accelerator is a device that increases the kinetic energy of electrically charged particles through the use of electric and magnetic fields. The cyclotron, invented in 1931, is an early type of particle accelerator that uses a high frequency oscillator to accelerate positively charged particles in a spiral path between two "D-shaped" electrodes placed in a strong magnetic field. As the particles accelerate, they travel in larger circular paths until they exit and can be used for nuclear reaction experiments or medical treatments like cancer therapy.
Cyclotron (1)
Cyclotrons accelerate charged particles using oscillating electric fields generated between hollow metal chambers called dees. A positive ion is placed between the dees and accelerated toward the first dee when it is negatively charged. The magnetic field causes the ion to travel in a semicircular path, and it is accelerated again when the dee polarities reverse just as the ion reaches the gap. This process continues to accelerate the ion with each pass. Cyclotrons can be used to accelerate proton beams for nuclear physics experiments and cancer treatment through proton therapy.
Lasers & semiconductors 2008 prelim solutions
Electrons and holes are urged towards the junction region when the diode is in forward bias. This results in the reduction of the depletion region, thus allowing a current to flow. When a p-d is applied across a p-n junction diode in the forward bias mode, the width of the depletion layer decreases, allowing charge carriers to flow more easily across the junction. In reverse bias mode, the depletion layer width increases, preventing charge flow and making the diode act as an open switch.
Cyclotron
The cyclotron is a device that accelerates charged particles using electric and magnetic fields without the need for high voltages. It works by subjecting charged particles like protons to alternating electric fields while maintaining their circular path using a constant perpendicular magnetic field. This causes the particles to gain kinetic energy and travel in an increasingly larger circular trajectory with each pass through the electric field until they exit the cyclotron with energies in the MeV range, useful for applications like medical isotope production and cancer treatment.
instrumentation of mass spectrometry
This document provides an overview of the key components and operating principles of mass spectrometry. It discusses the inlet system, ion sources, mass analyzers, detectors, and vacuum system. Common types of ion sources like electron impact and chemical ionization are described. Popular mass analyzers such as quadrupole, time-of-flight, ion trap, and double focusing are explained. The document also covers the theory behind how mass spectrometry separates ions based on their mass-to-charge ratio and discusses the need for high vacuum levels in mass spectrometers.
Chapter2-Structure of Atom 2023.pptx
1. The document discusses the discovery of the electron through cathode ray experiments and the determination of the charge to mass ratio of electrons.
2. Rutherford's alpha particle scattering experiments showed that the atom has a small, dense nucleus containing positive charge and mass, surrounded by electrons. This led to the development of the Rutherford model of the atom.
3. The document also discusses the discovery of protons and neutrons, atomic number and mass number, isotopes, drawbacks of the Rutherford model, wave-particle duality of light, and Planck's quantum theory.
Current electricity
This document discusses how electric current flows in metallic conductors. It explains that metals contain free electrons that are not bound to any particular nucleus and can move throughout the material. When an electric field is applied, the free electrons drift in the opposite direction of the field, constituting an electric current. Their drift velocity depends on factors like the electric field strength, temperature, and material properties. The document also introduces concepts like relaxation time and how increasing certain variables affects resistance.
ATOMIC PHYSICS
This document provides an overview of atomic physics, including:
1. Models of the atom including Rutherford and Bohr models, and explanations of atomic energy levels and quantum numbers.
2. Quantum physics concepts including Planck's quantum theory, Einstein's theories of light and the photoelectric effect, and de Broglie's hypothesis of matter waves.
3. Lasers including production of laser light, properties, types, and applications.
4. Nuclear physics including structure of the nucleus, radioactive decay, nuclear stability, fission and fusion processes, and applications of nuclear technology.
Atoms Physics class 12th Nonmed
1) The document discusses Thomson's plum pudding model of the atom and its limitations. It then describes Rutherford's alpha scattering experiment, the conclusions he drew, and his nuclear model of the atom.
2) Bohr's model improved upon Rutherford's by proposing quantized electron orbits and energy levels based on Planck's quantum theory. This allowed Bohr to explain the hydrogen spectral series.
3) The document provides details of Thomson, Rutherford, and Bohr's atomic models, including their postulates and limitations. It discusses key experiments and conclusions that improved understanding of atomic structure over time.
Bandtheory of solids
The document discusses band theory of solids, which explains the electrical, thermal, and magnetic properties of solids. It begins by covering classical and quantum free electron theories, before introducing band theory. Band theory states that the motion of free electrons in solids is characterized by allowed energy bands separated by forbidden bands. The width of bands and size of gaps depends on factors like the periodic potential of the lattice and strength of scattering. Semiconductors have a small forbidden band gap, allowing electrical conductivity to be controlled by doping with impurities.
Magnetic force
Here are the key steps to solve this problem:
1) The electron is accelerated through 1 kV, so its kinetic energy is 1 keV = 1/2 * m_e * v^2. Solve for v.
2) In the region between the plates, the electric force F_E = qE and magnetic force F_B = qvB. For straight line motion, these forces must balance so F_E = F_B.
3) Set the two force expressions equal and solve for B.
4) Plug in the given values of q = -e, E = 100 V/20mm, and v calculated in step 1.
5) The required uniform magnetic
Module 1 Semiconductors (1).pptx
1) Semiconductors have energy band gaps between 1-4 eV allowing electrons to move between bands with small energy inputs, unlike insulators. Metals have overlapping or no bands.
2) Intrinsic semiconductors have small numbers of electrons and holes as charge carriers from thermal excitation breaking covalent bonds. Extrinsic semiconductors are doped with donor or acceptor impurities to add more free electrons or holes.
3) Donor impurities introduce extra electrons in the conduction band of n-type semiconductors. Acceptor impurities introduce holes in the valence band of p-type semiconductors.
Study on the Energy Level Splitting of the Francium Atom Fr in an External Ma...
In This paper the normal Francium atom is considered with the use of non relativistic quantum mechanical approach and the Bohrs atomic model. We study the energy shift values of a Francium atom by the external magnetic fields effect we considered the two cases that effect without external magnetic fields and those of with the external magnetic fields. Win Moe Thant "Study on the Energy Level Splitting of the Francium Atom (Fr) in an External Magnetic Field" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd26730.pdf Paper URL: https://www.ijtsrd.com/physics/atomic-physics/26730/study-on-the-energy-level-splitting-of-the-francium-atom-fr-in-an-external-magnetic-field/win-moe-thant
Final Crystal Field Theory.pptx
Crystal field theory describes how the degeneracy of electron orbitals, such as d or f orbitals, is broken due to the static electric field created by surrounding ligand charges. In an octahedral complex, the d orbitals of the central metal ion split into two sets of differing energies due to crystal field splitting. Low spin complexes favor pairing of electrons in the lower energy orbitals, while high spin complexes contain unpaired electrons. The orientation of d-orbitals and degree of splitting differs between octahedral, tetrahedral, square planar, and trigonal bipyramidal ligand geometries.
Electron Affinity And Ionization Energy
The document discusses energy gaps between electron shells in atoms. Electrons occupy discrete energy levels organized into shells. The energy required to excite an electron to a higher shell is equal to the energy released as light when the electron returns to a lower shell. Different elements emit different colors of light corresponding to their unique electron shell energy gaps. Fireworks emit various colors from metal salts as the metals' electrons move between shells and release energy as light.
sBetatron
The document summarizes the working principles of a betatron, which is a device that uses changing magnetic fields to accelerate electrons in a circular path. It describes how Donald Kerst constructed the first betatron in 1941 at the University of Illinois and successfully accelerated electrons, producing x-rays. The betatron operates by injecting electrons into a doughnut-shaped vacuum chamber located between the poles of an electromagnet. As the alternating magnetic field increases over time, it induces an electric field that accelerates the electrons in their circular orbit to high energies without changing their radius, following the betatron condition of ΦB = 2πr2B.
Modren physics
The document discusses the structure and composition of atomic nuclei. It notes that nuclei are made up of protons and neutrons, which themselves are composed of quarks. The size of nuclei scales approximately with the one-third power of the total number of nucleons. Nuclear forces that bind nuclei include the long-range electromagnetic force and a short-range strong nuclear force that is attractive between nucleons at distances greater than 1-2 femtometers but repulsive at shorter distances. This dual nature of the nuclear force is necessary to maintain nuclear stability.
Chapter 2 structure of atom class 11
1) Experiments with cathode ray tubes led to the discovery of the electron as a negatively charged fundamental particle.
2) Further experiments showed that atoms are mostly empty space and contain a small, dense nucleus made up of protons and neutrons, around which electrons orbit.
3) The photoelectric effect showed that light behaves as a particle (photon) rather than just a wave, transferring its energy in discrete quantized amounts to electrons and ejecting them from metal surfaces.
Atoms Class 12 NCERT chapter 12
Ernest Rutherford's alpha ray scattering experiment led him to propose the nuclear model of the atom. The key findings were:
1) Most alpha particles passed through the thin gold foil with little deflection, but a small percentage were deflected by large angles, including backwards.
2) This could only be explained if the positive charge of the atom was concentrated into a very small, dense nucleus.
3) Rutherford concluded atoms have a small, dense nucleus containing its positive charge and mass, with electrons orbiting the nucleus.
This nuclear model replaced the plum pudding model, but had its own limitations that were later addressed by Niels Bohr's model of electron orbits and quantization
chapter2-structureofatom-.pdf
In your previous class you have already studies about the structure of an atom but some of the exception you can learn here in this chapter how the structure of an atom is fully defined
Similar to How a medical cyclotron works by emmanuel w. fiagbedzi (20)
CHARGE PARTICLE ACCELERATORCharge particle accelerator
CHARGE PARTICLE ACCELERATORCharge particle accelerator
Study on the Energy Level Splitting of the Francium Atom Fr in an External Ma...
Study on the Energy Level Splitting of the Francium Atom Fr in an External Ma...
Recently uploaded
THEMATIC APPERCEPTION TEST(TAT) cognitive abilities, creativity, and critic...
THEMATIC APPERCEPTION TEST(TAT) cognitive abilities, creativity, and critic...Abdul Wali Khan University Mardan,kP,Pakistan
hematic appreciation test is a psychological assessment tool used to measure an individual's appreciation and understanding of specific themes or topics. This test helps to evaluate an individual's ability to connect different ideas and concepts within a given theme, as well as their overall comprehension and interpretation skills. The results of the test can provide valuable insights into an individual's cognitive abilities, creativity, and critical thinking skillsMicronuclei test.M.sc.zoology.fisheries.
Current Ms word generated power point presentation covers major details about the micronuclei test. It's significance and assays to conduct it. It is used to detect the micronuclei formation inside the cells of nearly every multicellular organism. It's formation takes place during chromosomal sepration at metaphase.
Sharlene Leurig - Enabling Onsite Water Use with Net Zero Water
Sharlene Leurig - Enabling Onsite Water Use with Net Zero WaterTexas Alliance of Groundwater Districts
Presented at June 6-7 Texas Alliance of Groundwater Districts Business Meetingbordetella pertussis.................................ppt
Bordettela is a gram negative cocobacilli spread by air born drop let
Remote Sensing and Computational, Evolutionary, Supercomputing, and Intellige...
Remote Sensing and Computational, Evolutionary, Supercomputing, and Intellige...University of Maribor
Slides from talk:
Aleš Zamuda: Remote Sensing and Computational, Evolutionary, Supercomputing, and Intelligent Systems.
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Inter-Society Networking Panel GRSS/MTT-S/CIS Panel Session: Promoting Connection and Cooperation
https://www.etran.rs/2024/en/home-english/Applied Science: Thermodynamics, Laws & Methodology.pdf
When I was asked to give a companion lecture in support of ‘The Philosophy of Science’ (https://shorturl.at/4pUXz) I decided not to walk through the detail of the many methodologies in order of use. Instead, I chose to employ a long standing, and ongoing, scientific development as an exemplar. And so, I chose the ever evolving story of Thermodynamics as a scientific investigation at its best.
Conducted over a period of >200 years, Thermodynamics R&D, and application, benefitted from the highest levels of professionalism, collaboration, and technical thoroughness. New layers of application, methodology, and practice were made possible by the progressive advance of technology. In turn, this has seen measurement and modelling accuracy continually improved at a micro and macro level.
Perhaps most importantly, Thermodynamics rapidly became a primary tool in the advance of applied science/engineering/technology, spanning micro-tech, to aerospace and cosmology. I can think of no better a story to illustrate the breadth of scientific methodologies and applications at their best.
Phenomics assisted breeding in crop improvement
As the population is increasing and will reach about 9 billion upto 2050. Also due to climate change, it is difficult to meet the food requirement of such a large population. Facing the challenges presented by resource shortages, climate
change, and increasing global population, crop yield and quality need to be improved in a sustainable way over the coming decades. Genetic improvement by breeding is the best way to increase crop productivity. With the rapid progression of functional
genomics, an increasing number of crop genomes have been sequenced and dozens of genes influencing key agronomic traits have been identified. However, current genome sequence information has not been adequately exploited for understanding
the complex characteristics of multiple gene, owing to a lack of crop phenotypic data. Efficient, automatic, and accurate technologies and platforms that can capture phenotypic data that can
be linked to genomics information for crop improvement at all growth stages have become as important as genotyping. Thus,
high-throughput phenotyping has become the major bottleneck restricting crop breeding. Plant phenomics has been defined as the high-throughput, accurate acquisition and analysis of multi-dimensional phenotypes
during crop growing stages at the organism level, including the cell, tissue, organ, individual plant, plot, and field levels. With the rapid development of novel sensors, imaging technology,
and analysis methods, numerous infrastructure platforms have been developed for phenotyping.
Describing and Interpreting an Immersive Learning Case with the Immersion Cub...
Current descriptions of immersive learning cases are often difficult or impossible to compare. This is due to a myriad of different options on what details to include, which aspects are relevant, and on the descriptive approaches employed. Also, these aspects often combine very specific details with more general guidelines or indicate intents and rationales without clarifying their implementation. In this paper we provide a method to describe immersive learning cases that is structured to enable comparisons, yet flexible enough to allow researchers and practitioners to decide which aspects to include. This method leverages a taxonomy that classifies educational aspects at three levels (uses, practices, and strategies) and then utilizes two frameworks, the Immersive Learning Brain and the Immersion Cube, to enable a structured description and interpretation of immersive learning cases. The method is then demonstrated on a published immersive learning case on training for wind turbine maintenance using virtual reality. Applying the method results in a structured artifact, the Immersive Learning Case Sheet, that tags the case with its proximal uses, practices, and strategies, and refines the free text case description to ensure that matching details are included. This contribution is thus a case description method in support of future comparative research of immersive learning cases. We then discuss how the resulting description and interpretation can be leveraged to change immersion learning cases, by enriching them (considering low-effort changes or additions) or innovating (exploring more challenging avenues of transformation). The method holds significant promise to support better-grounded research in immersive learning.
Equivariant neural networks and representation theory
Or: Beyond linear.
Abstract: Equivariant neural networks are neural networks that incorporate symmetries. The nonlinear activation functions in these networks result in interesting nonlinear equivariant maps between simple representations, and motivate the key player of this talk: piecewise linear representation theory.
Disclaimer: No one is perfect, so please mind that there might be mistakes and typos.
dtubbenhauer@gmail.com
Corrected slides: dtubbenhauer.com/talks.html
Immersive Learning That Works: Research Grounding and Paths Forward
We will metaverse into the essence of immersive learning, into its three dimensions and conceptual models. This approach encompasses elements from teaching methodologies to social involvement, through organizational concerns and technologies. Challenging the perception of learning as knowledge transfer, we introduce a 'Uses, Practices & Strategies' model operationalized by the 'Immersive Learning Brain' and ‘Immersion Cube’ frameworks. This approach offers a comprehensive guide through the intricacies of immersive educational experiences and spotlighting research frontiers, along the immersion dimensions of system, narrative, and agency. Our discourse extends to stakeholders beyond the academic sphere, addressing the interests of technologists, instructional designers, and policymakers. We span various contexts, from formal education to organizational transformation to the new horizon of an AI-pervasive society. This keynote aims to unite the iLRN community in a collaborative journey towards a future where immersive learning research and practice coalesce, paving the way for innovative educational research and practice landscapes.
3D Hybrid PIC simulation of the plasma expansion (ISSS-14)
3D Particle-In-Cell (PIC) algorithm,
Plasma expansion in the dipole magnetic field.
原版制作(carleton毕业证书)卡尔顿大学毕业证硕士文凭原版一模一样
原版纸张【微信：741003700 】【(carleton毕业证书)卡尔顿大学毕业证】【微信：741003700 】学位证，留信认证（真实可查，永久存档）offer、雅思、外壳等材料/诚信可靠,可直接看成品样本，帮您解决无法毕业带来的各种难题！外壳，原版制作，诚信可靠，可直接看成品样本。行业标杆！精益求精，诚心合作，真诚制作！多年品质 ,按需精细制作，24小时接单,全套进口原装设备。十五年致力于帮助留学生解决难题，包您满意。
本公司拥有海外各大学样板无数，能完美还原海外各大学 Bachelor Diploma degree, Master Degree Diploma
1:1完美还原海外各大学毕业材料上的工艺：水印，阴影底纹，钢印LOGO烫金烫银，LOGO烫金烫银复合重叠。文字图案浮雕、激光镭射、紫外荧光、温感、复印防伪等防伪工艺。材料咨询办理、认证咨询办理请加学历顾问Q/微741003700
留信网认证的作用:
1:该专业认证可证明留学生真实身份
2:同时对留学生所学专业登记给予评定
3:国家专业人才认证中心颁发入库证书
4:这个认证书并且可以归档倒地方
5:凡事获得留信网入网的信息将会逐步更新到个人身份内，将在公安局网内查询个人身份证信息后，同步读取人才网入库信息
6:个人职称评审加20分
7:个人信誉贷款加10分
8:在国家人才网主办的国家网络招聘大会中纳入资料，供国家高端企业选择人才
The use of Nauplii and metanauplii artemia in aquaculture (brine shrimp).pptx
Although Artemia has been known to man for centuries, its use as a food for the culture of larval organisms apparently began only in the 1930s, when several investigators found that it made an excellent food for newly hatched fish larvae (Litvinenko et al., 2023). As aquaculture developed in the 1960s and ‘70s, the use of Artemia also became more widespread, due both to its convenience and to its nutritional value for larval organisms (Arenas-Pardo et al., 2024). The fact that Artemia dormant cysts can be stored for long periods in cans, and then used as an off-the-shelf food requiring only 24 h of incubation makes them the most convenient, least labor-intensive, live food available for aquaculture (Sorgeloos & Roubach, 2021). The nutritional value of Artemia, especially for marine organisms, is not constant, but varies both geographically and temporally. During the last decade, however, both the causes of Artemia nutritional variability and methods to improve poorquality Artemia have been identified (Loufi et al., 2024).
Brine shrimp (Artemia spp.) are used in marine aquaculture worldwide. Annually, more than 2,000 metric tons of dry cysts are used for cultivation of fish, crustacean, and shellfish larva. Brine shrimp are important to aquaculture because newly hatched brine shrimp nauplii (larvae) provide a food source for many fish fry (Mozanzadeh et al., 2021). Culture and harvesting of brine shrimp eggs represents another aspect of the aquaculture industry. Nauplii and metanauplii of Artemia, commonly known as brine shrimp, play a crucial role in aquaculture due to their nutritional value and suitability as live feed for many aquatic species, particularly in larval stages (Sorgeloos & Roubach, 2021).
在线办理(salfor毕业证书)索尔福德大学毕业证毕业完成信一模一样
学校原件一模一样【微信：741003700 】《(salfor毕业证书)索尔福德大学毕业证》【微信：741003700 】学位证，留信认证（真实可查，永久存档）原件一模一样纸张工艺/offer、雅思、外壳等材料/诚信可靠,可直接看成品样本，帮您解决无法毕业带来的各种难题！外壳，原版制作，诚信可靠，可直接看成品样本。行业标杆！精益求精，诚心合作，真诚制作！多年品质 ,按需精细制作，24小时接单,全套进口原装设备。十五年致力于帮助留学生解决难题，包您满意。
本公司拥有海外各大学样板无数，能完美还原。
1:1完美还原海外各大学毕业材料上的工艺：水印，阴影底纹，钢印LOGO烫金烫银，LOGO烫金烫银复合重叠。文字图案浮雕、激光镭射、紫外荧光、温感、复印防伪等防伪工艺。材料咨询办理、认证咨询办理请加学历顾问Q/微741003700
【主营项目】
一.毕业证【q微741003700】成绩单、使馆认证、教育部认证、雅思托福成绩单、学生卡等！
二.真实使馆公证(即留学回国人员证明,不成功不收费)
三.真实教育部学历学位认证（教育部存档！教育部留服网站永久可查）
四.办理各国各大学文凭(一对一专业服务,可全程监控跟踪进度)
如果您处于以下几种情况：
◇在校期间，因各种原因未能顺利毕业……拿不到官方毕业证【q/微741003700】
◇面对父母的压力，希望尽快拿到；
◇不清楚认证流程以及材料该如何准备；
◇回国时间很长，忘记办理；
◇回国马上就要找工作，办给用人单位看；
◇企事业单位必须要求办理的
◇需要报考公务员、购买免税车、落转户口
◇申请留学生创业基金
留信网认证的作用:
1:该专业认证可证明留学生真实身份
2:同时对留学生所学专业登记给予评定
3:国家专业人才认证中心颁发入库证书
4:这个认证书并且可以归档倒地方
5:凡事获得留信网入网的信息将会逐步更新到个人身份内，将在公安局网内查询个人身份证信息后，同步读取人才网入库信息
6:个人职称评审加20分
7:个人信誉贷款加10分
8:在国家人才网主办的国家网络招聘大会中纳入资料，供国家高端企业选择人才
如何办理(uvic毕业证书)维多利亚大学毕业证本科学位证书原版一模一样
原版纸张【微信：741003700 】【(uvic毕业证书)维多利亚大学毕业证】【微信：741003700 】学位证，留信认证（真实可查，永久存档）offer、雅思、外壳等材料/诚信可靠,可直接看成品样本，帮您解决无法毕业带来的各种难题！外壳，原版制作，诚信可靠，可直接看成品样本。行业标杆！精益求精，诚心合作，真诚制作！多年品质 ,按需精细制作，24小时接单,全套进口原装设备。十五年致力于帮助留学生解决难题，包您满意。
本公司拥有海外各大学样板无数，能完美还原海外各大学 Bachelor Diploma degree, Master Degree Diploma
1:1完美还原海外各大学毕业材料上的工艺：水印，阴影底纹，钢印LOGO烫金烫银，LOGO烫金烫银复合重叠。文字图案浮雕、激光镭射、紫外荧光、温感、复印防伪等防伪工艺。材料咨询办理、认证咨询办理请加学历顾问Q/微741003700
留信网认证的作用:
1:该专业认证可证明留学生真实身份
2:同时对留学生所学专业登记给予评定
3:国家专业人才认证中心颁发入库证书
4:这个认证书并且可以归档倒地方
5:凡事获得留信网入网的信息将会逐步更新到个人身份内，将在公安局网内查询个人身份证信息后，同步读取人才网入库信息
6:个人职称评审加20分
7:个人信誉贷款加10分
8:在国家人才网主办的国家网络招聘大会中纳入资料，供国家高端企业选择人才
Randomised Optimisation Algorithms in DAPHNE
Slides from talk:
Aleš Zamuda: Randomised Optimisation Algorithms in DAPHNE .
Austrian-Slovenian HPC Meeting 2024 – ASHPC24, Seeblickhotel Grundlsee in Austria, 10–13 June 2024
https://ashpc.eu/
Unlocking the mysteries of reproduction: Exploring fecundity and gonadosomati...
The pygmy halfbeak Dermogenys colletei, is known for its viviparous nature, this presents an intriguing case of relatively low fecundity, raising questions about potential compensatory reproductive strategies employed by this species. Our study delves into the examination of fecundity and the Gonadosomatic Index (GSI) in the Pygmy Halfbeak, D. colletei (Meisner, 2001), an intriguing viviparous fish indigenous to Sarawak, Borneo. We hypothesize that the Pygmy halfbeak, D. colletei, may exhibit unique reproductive adaptations to offset its low fecundity, thus enhancing its survival and fitness. To address this, we conducted a comprehensive study utilizing 28 mature female specimens of D. colletei, carefully measuring fecundity and GSI to shed light on the reproductive adaptations of this species. Our findings reveal that D. colletei indeed exhibits low fecundity, with a mean of 16.76 ± 2.01, and a mean GSI of 12.83 ± 1.27, providing crucial insights into the reproductive mechanisms at play in this species. These results underscore the existence of unique reproductive strategies in D. colletei, enabling its adaptation and persistence in Borneo's diverse aquatic ecosystems, and call for further ecological research to elucidate these mechanisms. This study lends to a better understanding of viviparous fish in Borneo and contributes to the broader field of aquatic ecology, enhancing our knowledge of species adaptations to unique ecological challenges.
20240520 Planning a Circuit Simulator in JavaScript.pptx
Evaporation step counter work. I have done a physical experiment.
(Work in progress.)
Recently uploaded (20)
THEMATIC APPERCEPTION TEST(TAT) cognitive abilities, creativity, and critic...
THEMATIC APPERCEPTION TEST(TAT) cognitive abilities, creativity, and critic...
Sharlene Leurig - Enabling Onsite Water Use with Net Zero Water
Sharlene Leurig - Enabling Onsite Water Use with Net Zero Water
bordetella pertussis.................................ppt
bordetella pertussis.................................ppt
Remote Sensing and Computational, Evolutionary, Supercomputing, and Intellige...
Remote Sensing and Computational, Evolutionary, Supercomputing, and Intellige...
Applied Science: Thermodynamics, Laws & Methodology.pdf
Applied Science: Thermodynamics, Laws & Methodology.pdf
Describing and Interpreting an Immersive Learning Case with the Immersion Cub...
Describing and Interpreting an Immersive Learning Case with the Immersion Cub...
aziz sancar nobel prize winner: from mardin to nobel
aziz sancar nobel prize winner: from mardin to nobel
Equivariant neural networks and representation theory
Equivariant neural networks and representation theory
Immersive Learning That Works: Research Grounding and Paths Forward
Immersive Learning That Works: Research Grounding and Paths Forward
3D Hybrid PIC simulation of the plasma expansion (ISSS-14)
3D Hybrid PIC simulation of the plasma expansion (ISSS-14)
The use of Nauplii and metanauplii artemia in aquaculture (brine shrimp).pptx
The use of Nauplii and metanauplii artemia in aquaculture (brine shrimp).pptx
Unlocking the mysteries of reproduction: Exploring fecundity and gonadosomati...
Unlocking the mysteries of reproduction: Exploring fecundity and gonadosomati...
20240520 Planning a Circuit Simulator in JavaScript.pptx
20240520 Planning a Circuit Simulator in JavaScript.pptx
How a medical cyclotron works by emmanuel w. fiagbedzi
- 1. BY Emmanuel W. Fiagbedzi Master In Medical Physics Student ICTP-UNITS Trieste-Italy 06/04/15 1
- 2. A medical cyclotron is a type of compact particle accelerator used to produce quantities of radioactive isotopes called positron emitters. In general, cyclotron is a particle accelerator that Sends charged particles, which constantly accelerate through a ‘Dee’, through a circular path until they are (most likely) directed towards a designated target for a specific purpose. The cyclotron was invented by Ernest Lawrence and M.S Livingston of the University of California, Berkeley, where it was first operated in 1932. Cyclotron are source of a large number of high-energy (MeV) range charged particle 06/04/15 2
- 3. It consists of two D shaped metal boxes (about 21 in diameter) with their″ straight sides facing each other. There is a very small gap between these Dee’s faces across which a high potential difference (of order of 105 volts) is applied by a high frequency (10-15 mega cycles per second) oscillator. Thus an alternating electric field is established between Dee’s during one half cycle, one dee is positive and the other is negative while during the next half cycle, the other is positive and one is negative. A source of particle (heavy hydrogen for producing deuterons or a proton) is placed between the faces. The whole apparatus is placed between the pole pieces a very strong magnet. 06/04/15 3
- 4. 06/04/15 4
- 5. Cyclotron Component Major Exterior Component Shielding Major Interior Component Vacuum system Ion Source Magnetic system Radiofrequency system Dees Targets 06/04/15 5
- 6. 06/04/15 6
- 7. Cyclotrons accelerate charged particle beams using a high frequency alternating voltage which is applied between two "D"-shaped electrodes (also called "dees"). D1 and D2 are hollow evacuated metal chambers. The dees are connected to a high frequency oscillator. The two dees are enclosed in a evacuated steel box. The box is placed in a strong magnetic field produced by two pole pieces of electromagnet. The positive ion to be accelerated is placed in between the dees. 06/04/15 7
- 8. Now suppose a deuteron is at the centre of the gap and D1 is at negative potential compared to D2 then deuterons will be accelerated by the electric field between the dees towards D1. Since magnetic field B is perpendicular to the direction of motion of deuteron, a force will act on the particle given by F = qv x B (where v and B are vectors) = qvB Due to perpendicular magnetic field it describes a semi circular path inside D1 of radius r=mv/Bq (Centripetal force=Magnetic force) 06/04/15 8
- 9. The time period and frequency is independent of speed of charge and radius of circular path. If this frequency is equal to the frequency of the oscillator then by the time particle complete half revolution the polarity of the field will change. Deuteron will again be accelerated across the gap, its velocity will increase so that now it will move in a circular path of greater radius but its frequency will not be affected and the process of acceleration continues. The particle is thus accelerated to gain high velocity. Its kinetic energy increases and when radius of the path reaches up to the value of the radius of the dee (R), beam is deflected by a negatively charged plate. Therefore with r=R, its kinetic energy is maximum. 06/04/15 9
- 10. So the necessary condition for accelerating the deuterons is f= fo where f0 is oscillator frequency. This is called resonance condition As velocity attained is high, we choose heavier particles e.g., protons, deuterons for acceleration in cyclotron. The reason is that at such high velocities, mass varies with velocity and f will then depend on velocity, upsetting the resonance condition. This variation in mass is more marked in the case of lighter particles. So cyclotron is suitable only for accelerating heavy particle like protons, deuterons a - particles etc. 06/04/15 10
- 11. 06/04/15 11
- 12. Electrons can not be accelerated by cyclotrons because the mass of electron is very small and a small increase in energy of electron makes the electrons move with very high speed. As a result of it the electron go quickly out of step with oscillating electric field, it is for these reasons that other accelerating machines such as synchrotron, betatron (for accelerating electrons) have been developed. Cyclotron can not be used for accelerating uncharged particle like neutrons. 06/04/15 12
- 13. Cyclotrons are a clean nuclear technology that create very little radioactive waste as a result of their operation. Cyclotrons are helpful since its products are used in PET for most advanced medical diagnostic imaging technology like early and accurate detection of cancer and detecting certain diseases of the heart and brain. 06/04/15 13
- 14. En.wikipedia.org/wiki/cyclotron www.icbse.com/topic/cyclotron www.lawsonreach.com Thank you 06/04/15 14