jaap corstens - Academia.edu (original) (raw)

Papers by jaap corstens

AIP Conference Proceedings, 2009

One of the most compelling reasons to use external injection of electrons into a laser wakefield ... more One of the most compelling reasons to use external injection of electrons into a laser wakefield accelerator is to improve the stability and reproducibility of the accelerated electrons. We have built a simulation tool based on particle tracking to investigate the expected output parameters. Specifically, we are simulating the variations in energy and bunch charge under the influence of variations in laser power and timing jitter. In these simulations a a0 = 0.32 to a0 = 1.02 laser pulse with 10% shot-to-shot energy fluctuation is focused into a plasma waveguide with a density of 1.0×1024 m-3 and a calculated matched spot size of 50.2 mum. The timing of the injected electron bunch with respect to the laser pulse is varied from up to 1 ps from the standard timing (1 ps ahead or behind the laser pulse, depending on the regime). The simulation method and first results will be presented. Shortcomings and possible extensions to the model will be discussed.

Physical Review Special Topics - Accelerators and Beams, 2009

The effects of experimental variations in the synchronization, laser power, and plasma density on... more The effects of experimental variations in the synchronization, laser power, and plasma density on the final beam parameters of externally injected electrons accelerated in a plasma wave are studied using a hybrid model. This model combines a relativistic fluid description of the plasma wave generated by the laser pulse with particle tracking of the accelerated electrons. For cases in which the effects of beam loading and laser depletion can be neglected, the two parts can be separated, allowing a significant reduction in computational power needed compared to particle in cell codes. Two different approaches to externally injecting electrons into plasma waves are studied: In the first case, the electrons are injected behind a laser pulse with a 0 ¼ 0:32. In the second case, electrons are injected in front of the laser pulse in three different laser regimes a 0 ¼ 0:32, a 0 ¼ 0:56, and a 0 ¼ 1:02, ranging from linear to nonlinear. For these four cases, the effects of expected experimental variations in synchronization (AE 500 fs), laser power (AE 10%), and plasma density (AE 30%) are studied. From these simulations, it becomes clear that in some cases, even a small variation in one of these parameters can create a large change in the final energy, energy spread, and trapped charge. For lower laser intensities, the method of injecting behind the laser pulse is the least sensitive to fluctuations while injection in front of the laser pulse becomes less sensitive at higher intensities.

A Hamiltonian theory, in which electromagnetic space waves and longitudinal electric fields are i... more A Hamiltonian theory, in which electromagnetic space waves and longitudinal electric fields are incorporated by means of their vector potentials, is used to calculate particle motion in linear electron accelerators. In particular these calculations have been applied to the Eindhoven 10 MeV travelling-wave linac as well as to the Eindhoven racetrack microtron accelerating cavity. The calculations are in good agreement with simulations performed by particle-tracking codes.

A Hamiltonian theory, in which electromagnetic space waves and longitudinal electric fields are i... more A Hamiltonian theory, in which electromagnetic space waves and longitudinal electric fields are incorporated by means of their vector potentials, is used to calculate particle motion in linear electron accelerators. In particular these calculations have been applied to the Eindhoven 10 MeV travelling-wave linac as well as to the Eindhoven racetrack microtron accelerating cavity. The calculations are in good agreement with simulations performed by particle-tracking codes.

Nuclear Instruments and …, 2004

... distribution function is split into two parts: a part containing a Dirac delta function, desc... more ... distribution function is split into two parts: a part containing a Dirac delta function, describing the unscattered part, and a part describing the distribution after at least one scattering event. Bielajew [7] gave an approximate numerical treatment of Eq. (5), for both the plural and the ...

Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment - NUCL INSTRUM METH PHYS RES A, 1999

A Hamiltonian theory has been formulated, which is used to calculate accelerated particle motion ... more A Hamiltonian theory has been formulated, which is used to calculate accelerated particle motion in standing-wave RF structures. In particular, these calculations have been applied to the Eindhoven racetrack microtron accelerating cavity. The calculations are in excellent agreement with simulations performed by particle-tracking codes.

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2006

Generation of resonant transition radiation (RTR) is potentially a method to obtain useable fluxe... more Generation of resonant transition radiation (RTR) is potentially a method to obtain useable fluxes of tuneable, relatively narrow-band soft X-ray radiation from compact (<10 MeV) electron accelerators. The RTR targets to be used are periodic multilayer structures of two materials with low absorption and high refractive-index contrast in the soft X-ray range. We present a model for optimizing the parameters of such targets. The model is based on an extension of the Ginzburg Franck equation for transition radiation from a single interface. The model also accounts for absorption, elastic scattering, energy spread of the electron beam and inaccuracy in the foil thicknesses. Two examples are treated. First, a multilayer structure consisting of Mo foils and vacuum spacers is optimized for generation of 13.5 nm radiation by an electron beam with energy of 9 MeV. The model predicts a yield of up to 0.045 photons per electron per (eV sr). Second, a multilayer structure consisting of Al foils and vacuum spacers is optimized for generation of 0.83 nm radiation by 150 MeV electrons. For the latter case, the model predicts a yield of up to 3.7 photons per electron per (eV sr).

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2006

Generation of resonant transition radiation (RTR) is potentially a method to obtain useable fluxe... more Generation of resonant transition radiation (RTR) is potentially a method to obtain useable fluxes of tuneable, relatively narrow-band soft X-ray radiation from compact (<10 MeV) electron accelerators. The RTR targets to be used are periodic multilayer structures of two materials with low absorption and high refractive-index contrast in the soft X-ray range. We present a model for optimizing the parameters of such targets. The model is based on an extension of the Ginzburg Franck equation for transition radiation from a single interface. The model also accounts for absorption, elastic scattering, energy spread of the electron beam and inaccuracy in the foil thicknesses. Two examples are treated. First, a multilayer structure consisting of Mo foils and vacuum spacers is optimized for generation of 13.5 nm radiation by an electron beam with energy of 9 MeV. The model predicts a yield of up to 0.045 photons per electron per (eV sr). Second, a multilayer structure consisting of Al foils and vacuum spacers is optimized for generation of 0.83 nm radiation by 150 MeV electrons. For the latter case, the model predicts a yield of up to 3.7 photons per electron per (eV sr).

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2007

ABSTRACT A possible source of radiation in the X-ray range can be obtained by penetration of a di... more ABSTRACT A possible source of radiation in the X-ray range can be obtained by penetration of a dielectric slab by electrons with sufficient kinetic energy. We present a near-exact solution of Maxwell equations to obtain the intensity of Cherenkov (and transition) radiation from slabs thicker than the absorption length, the only approximation being that the observation angle of the radiation with respect to the electron axis is taken to be small. Contrary to earlier models our model accounts for all relativistic electron energies, dielectric constants and grazing incidence angles. Also scattering of the electrons is incorporated very accurately, including the effect of scattering on the electro-magnetic fields within the slab. We report significant differences with earlier calculation for radiation yields from e.g. Si. A new effect has been found for intermediate angles of incidence (around 45°). At these angles, the cone of Cherenkov radiation exhibits pronounced minima near the direction perpendicular to the plane of incidence. We present arguments based on the special characteristics of Cherenkov radiation why in that direction internal reflection of the radiation occurs at the medium–vacuum interface.

Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366), 1999

In this paper, we present the particle dynamics in lowenergy travelling-wave linear accelerators,... more In this paper, we present the particle dynamics in lowenergy travelling-wave linear accelerators, applying analytical theory, based on Hamiltonian mechanics, and numerical simulations, performed by commercially available codes. The paper is an extension on earlier work, presented at EPAC'98. Cylindrical coordinates are used and solenoid magnetic fields are incorporated. The Hamiltonian equations of motion are given and examples of calculations are presented and compared to numerical simulations, yielding excellent agreement between both approaches.

Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366), 1999

In this paper, we present the particle dynamics in lowenergy travelling-wave linear accelerators,... more In this paper, we present the particle dynamics in lowenergy travelling-wave linear accelerators, applying analytical theory, based on Hamiltonian mechanics, and numerical simulations, performed by commercially available codes. The paper is an extension on earlier work, presented at EPAC'98. Cylindrical coordinates are used and solenoid magnetic fields are incorporated. The Hamiltonian equations of motion are given and examples of calculations are presented and compared to numerical simulations, yielding excellent agreement between both approaches.

AIP Conference Proceedings, 2009

One of the most compelling reasons to use external injection of electrons into a laser wakefield ... more One of the most compelling reasons to use external injection of electrons into a laser wakefield accelerator is to improve the stability and reproducibility of the accelerated electrons. We have built a simulation tool based on particle tracking to investigate the expected output parameters. Specifically, we are simulating the variations in energy and bunch charge under the influence of variations in laser power and timing jitter. In these simulations a a0 = 0.32 to a0 = 1.02 laser pulse with 10% shot-to-shot energy fluctuation is focused into a plasma waveguide with a density of 1.0×1024 m-3 and a calculated matched spot size of 50.2 mum. The timing of the injected electron bunch with respect to the laser pulse is varied from up to 1 ps from the standard timing (1 ps ahead or behind the laser pulse, depending on the regime). The simulation method and first results will be presented. Shortcomings and possible extensions to the model will be discussed.

Physical Review Special Topics - Accelerators and Beams, 2009

The effects of experimental variations in the synchronization, laser power, and plasma density on... more The effects of experimental variations in the synchronization, laser power, and plasma density on the final beam parameters of externally injected electrons accelerated in a plasma wave are studied using a hybrid model. This model combines a relativistic fluid description of the plasma wave generated by the laser pulse with particle tracking of the accelerated electrons. For cases in which the effects of beam loading and laser depletion can be neglected, the two parts can be separated, allowing a significant reduction in computational power needed compared to particle in cell codes. Two different approaches to externally injecting electrons into plasma waves are studied: In the first case, the electrons are injected behind a laser pulse with a 0 ¼ 0:32. In the second case, electrons are injected in front of the laser pulse in three different laser regimes a 0 ¼ 0:32, a 0 ¼ 0:56, and a 0 ¼ 1:02, ranging from linear to nonlinear. For these four cases, the effects of expected experimental variations in synchronization (AE 500 fs), laser power (AE 10%), and plasma density (AE 30%) are studied. From these simulations, it becomes clear that in some cases, even a small variation in one of these parameters can create a large change in the final energy, energy spread, and trapped charge. For lower laser intensities, the method of injecting behind the laser pulse is the least sensitive to fluctuations while injection in front of the laser pulse becomes less sensitive at higher intensities.

A Hamiltonian theory, in which electromagnetic space waves and longitudinal electric fields are i... more A Hamiltonian theory, in which electromagnetic space waves and longitudinal electric fields are incorporated by means of their vector potentials, is used to calculate particle motion in linear electron accelerators. In particular these calculations have been applied to the Eindhoven 10 MeV travelling-wave linac as well as to the Eindhoven racetrack microtron accelerating cavity. The calculations are in good agreement with simulations performed by particle-tracking codes.

A Hamiltonian theory, in which electromagnetic space waves and longitudinal electric fields are i... more A Hamiltonian theory, in which electromagnetic space waves and longitudinal electric fields are incorporated by means of their vector potentials, is used to calculate particle motion in linear electron accelerators. In particular these calculations have been applied to the Eindhoven 10 MeV travelling-wave linac as well as to the Eindhoven racetrack microtron accelerating cavity. The calculations are in good agreement with simulations performed by particle-tracking codes.

Nuclear Instruments and …, 2004

... distribution function is split into two parts: a part containing a Dirac delta function, desc... more ... distribution function is split into two parts: a part containing a Dirac delta function, describing the unscattered part, and a part describing the distribution after at least one scattering event. Bielajew [7] gave an approximate numerical treatment of Eq. (5), for both the plural and the ...

Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment - NUCL INSTRUM METH PHYS RES A, 1999

A Hamiltonian theory has been formulated, which is used to calculate accelerated particle motion ... more A Hamiltonian theory has been formulated, which is used to calculate accelerated particle motion in standing-wave RF structures. In particular, these calculations have been applied to the Eindhoven racetrack microtron accelerating cavity. The calculations are in excellent agreement with simulations performed by particle-tracking codes.

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2006

Generation of resonant transition radiation (RTR) is potentially a method to obtain useable fluxe... more Generation of resonant transition radiation (RTR) is potentially a method to obtain useable fluxes of tuneable, relatively narrow-band soft X-ray radiation from compact (<10 MeV) electron accelerators. The RTR targets to be used are periodic multilayer structures of two materials with low absorption and high refractive-index contrast in the soft X-ray range. We present a model for optimizing the parameters of such targets. The model is based on an extension of the Ginzburg Franck equation for transition radiation from a single interface. The model also accounts for absorption, elastic scattering, energy spread of the electron beam and inaccuracy in the foil thicknesses. Two examples are treated. First, a multilayer structure consisting of Mo foils and vacuum spacers is optimized for generation of 13.5 nm radiation by an electron beam with energy of 9 MeV. The model predicts a yield of up to 0.045 photons per electron per (eV sr). Second, a multilayer structure consisting of Al foils and vacuum spacers is optimized for generation of 0.83 nm radiation by 150 MeV electrons. For the latter case, the model predicts a yield of up to 3.7 photons per electron per (eV sr).

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2006

Generation of resonant transition radiation (RTR) is potentially a method to obtain useable fluxe... more Generation of resonant transition radiation (RTR) is potentially a method to obtain useable fluxes of tuneable, relatively narrow-band soft X-ray radiation from compact (<10 MeV) electron accelerators. The RTR targets to be used are periodic multilayer structures of two materials with low absorption and high refractive-index contrast in the soft X-ray range. We present a model for optimizing the parameters of such targets. The model is based on an extension of the Ginzburg Franck equation for transition radiation from a single interface. The model also accounts for absorption, elastic scattering, energy spread of the electron beam and inaccuracy in the foil thicknesses. Two examples are treated. First, a multilayer structure consisting of Mo foils and vacuum spacers is optimized for generation of 13.5 nm radiation by an electron beam with energy of 9 MeV. The model predicts a yield of up to 0.045 photons per electron per (eV sr). Second, a multilayer structure consisting of Al foils and vacuum spacers is optimized for generation of 0.83 nm radiation by 150 MeV electrons. For the latter case, the model predicts a yield of up to 3.7 photons per electron per (eV sr).

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2007

ABSTRACT A possible source of radiation in the X-ray range can be obtained by penetration of a di... more ABSTRACT A possible source of radiation in the X-ray range can be obtained by penetration of a dielectric slab by electrons with sufficient kinetic energy. We present a near-exact solution of Maxwell equations to obtain the intensity of Cherenkov (and transition) radiation from slabs thicker than the absorption length, the only approximation being that the observation angle of the radiation with respect to the electron axis is taken to be small. Contrary to earlier models our model accounts for all relativistic electron energies, dielectric constants and grazing incidence angles. Also scattering of the electrons is incorporated very accurately, including the effect of scattering on the electro-magnetic fields within the slab. We report significant differences with earlier calculation for radiation yields from e.g. Si. A new effect has been found for intermediate angles of incidence (around 45°). At these angles, the cone of Cherenkov radiation exhibits pronounced minima near the direction perpendicular to the plane of incidence. We present arguments based on the special characteristics of Cherenkov radiation why in that direction internal reflection of the radiation occurs at the medium–vacuum interface.

Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366), 1999

In this paper, we present the particle dynamics in lowenergy travelling-wave linear accelerators,... more In this paper, we present the particle dynamics in lowenergy travelling-wave linear accelerators, applying analytical theory, based on Hamiltonian mechanics, and numerical simulations, performed by commercially available codes. The paper is an extension on earlier work, presented at EPAC'98. Cylindrical coordinates are used and solenoid magnetic fields are incorporated. The Hamiltonian equations of motion are given and examples of calculations are presented and compared to numerical simulations, yielding excellent agreement between both approaches.

Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366), 1999

In this paper, we present the particle dynamics in lowenergy travelling-wave linear accelerators,... more In this paper, we present the particle dynamics in lowenergy travelling-wave linear accelerators, applying analytical theory, based on Hamiltonian mechanics, and numerical simulations, performed by commercially available codes. The paper is an extension on earlier work, presented at EPAC'98. Cylindrical coordinates are used and solenoid magnetic fields are incorporated. The Hamiltonian equations of motion are given and examples of calculations are presented and compared to numerical simulations, yielding excellent agreement between both approaches.