Relativistic Electron-cyclotron Resonances in Laser Wakefield Acceleration

Relativistic Electron-cyclotron Resonances in Laser Wakefield Acceleration PDF Author: Matthew Schwab
Publisher:
ISBN:
Category :
Languages : de
Pages : 0

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Book Description
In this thesis, the magnetized, relativistic plasma that overlaps the pump laser in Laser Wakefield Acceleration (LWFA) was investigated. The Jeti 40 laser was used to drive the plasma wave and a transverse, few-cycle probe pulse in the visible to near-infrared spectrum was implemented to image the laser-plasma interaction. The recorded shadowgrams were sorted depending on the properties of the accelerated electron bunches, and subsequently stitched together based on the timing delay between the pump and probe beams. The resulting data showed two signatures unique to the relativistic, magnetized plasma near the pump pulse. Firstly, a significant change in the brightness modulation of the shadowgrams, coinciding with the location of the pump pulse, shows a strong dependence on the pump's propagation length and the probe's spectrum and polarization. Secondly, after ~1.5 mm of propagation in the plasma, polarization-dependent diffraction rings appear in front of the plasma wave. A mathematical model using relativistic corrections to the Appleton-Hartree equation was developed to explain these signals. By combining the model with data from 2D Particle-in-Cell (PIC) simulations using the VSim code, the plasma's birefringent refractive index distribution was investigated. Simulated shadowgrams of a 3D PIC simulation using the EPOCH code were also analyzed with respect to the aforementioned signals. The results of the study present a compelling description of the pump-plasma interaction. The previously unknown signals arise from relativistic, electron-cyclotron motion originating in the 10s of kilotesla strong magnetic fields of the pump pulse. Advantageously, a VIS-NIR probe is resonant with the cyclotron frequencies at the peak of the pump. With further refinement, the measurement of this phenomenon could allow for the non-invasive experimental visualization of the pump laser's spatio-temporal energy distribution and evolution during propagation through the plasma.

Relativistic Electron-cyclotron Resonances in Laser Wakefield Acceleration

Relativistic Electron-cyclotron Resonances in Laser Wakefield Acceleration PDF Author: Matthew Schwab
Publisher:
ISBN:
Category :
Languages : de
Pages : 0

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Book Description
In this thesis, the magnetized, relativistic plasma that overlaps the pump laser in Laser Wakefield Acceleration (LWFA) was investigated. The Jeti 40 laser was used to drive the plasma wave and a transverse, few-cycle probe pulse in the visible to near-infrared spectrum was implemented to image the laser-plasma interaction. The recorded shadowgrams were sorted depending on the properties of the accelerated electron bunches, and subsequently stitched together based on the timing delay between the pump and probe beams. The resulting data showed two signatures unique to the relativistic, magnetized plasma near the pump pulse. Firstly, a significant change in the brightness modulation of the shadowgrams, coinciding with the location of the pump pulse, shows a strong dependence on the pump's propagation length and the probe's spectrum and polarization. Secondly, after ~1.5 mm of propagation in the plasma, polarization-dependent diffraction rings appear in front of the plasma wave. A mathematical model using relativistic corrections to the Appleton-Hartree equation was developed to explain these signals. By combining the model with data from 2D Particle-in-Cell (PIC) simulations using the VSim code, the plasma's birefringent refractive index distribution was investigated. Simulated shadowgrams of a 3D PIC simulation using the EPOCH code were also analyzed with respect to the aforementioned signals. The results of the study present a compelling description of the pump-plasma interaction. The previously unknown signals arise from relativistic, electron-cyclotron motion originating in the 10s of kilotesla strong magnetic fields of the pump pulse. Advantageously, a VIS-NIR probe is resonant with the cyclotron frequencies at the peak of the pump. With further refinement, the measurement of this phenomenon could allow for the non-invasive experimental visualization of the pump laser's spatio-temporal energy distribution and evolution during propagation through the plasma.

Relativistic Electron Cyclotron Resonance Heating

Relativistic Electron Cyclotron Resonance Heating PDF Author: Stephen Michael Hohs
Publisher:
ISBN:
Category :
Languages : en
Pages : 34

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Relativistic Theory of Electron Cyclotron Resonance Heating

Relativistic Theory of Electron Cyclotron Resonance Heating PDF Author:
Publisher:
ISBN:
Category : Cyclotron resonance
Languages : en
Pages :

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Cyclotron Resonances in Electron Cloud Dynamics

Cyclotron Resonances in Electron Cloud Dynamics PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
A new set of resonances for electron cloud dynamics in the presence of a magnetic field has been found. For short beam bunch lengths and low magnetic fields where lb“2pi c/omega c (with lb = bunch length, omega c = non-relativistic cyclotron frequency) resonances between the bunch frequency and harmonics of the electron cyclotron frequency cause an increase in the electron cloud density in narrow ranges of magnetic field near the resonances. For ILC parameters the increase in the density is up to a factor ~;;3, and the spatial distribution of the electrons is broader near resonances, lacking the well-defined vertical density"stripes" found for non-resonant cases. Simulations with the 2D computer code POSINST, as well as a single-particle tracking code, were used to elucidate the physics of the dynamics. The existence of the resonances has been confirmed in experiments at PEP-II. The resonances are expected to affect the electron cloud dynamics in the fringe fields of conventional lattice magnets and in wigglers, where the magnetic fields are low. Results of the simulations and experimental observations, the reason for the bunch-length dependence, and details of the dynamics are discussed here.

Electron Cloud Cyclotron Resonances in the Presence of a Short-bunch-length Relativistic Beam

Electron Cloud Cyclotron Resonances in the Presence of a Short-bunch-length Relativistic Beam PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 43

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Book Description
Computer simulations using the 2D code"POSINST" were used to study the formation of the electron cloud in the wiggler section of the positron damping ring of the International Linear Collider. In order to simulate an x-y slice of the wiggler (i.e., a slice perpendicular to the beam velocity), each simulation assumed a constant vertical magnetic field. At values of the magnetic field where the cyclotron frequency was an integral multiple of the bunch frequency, and where the field strength was less than approximately 0.6 T, equilibrium average electron densities were up to three times the density found at other neighboring field values. Effects of this resonance between the bunch and cyclotron frequency are expected to be non-negligible when the beam bunch length is much less than the product of the electron cyclotron period and the beam velocity, for a beam moving at v~;;c. Details of the dynamics of the resonance are described.

Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 384

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Coherent Radiation Generation and Particle Acceleration

Coherent Radiation Generation and Particle Acceleration PDF Author: A.M. Prokhorov
Publisher: American Institute of Physics
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 544

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Book Description
Market: For those involved in plasma physics, relativistic beam physics, radiation physics, energy physics, as well as particle accelerators and synchrotron radiation. "An excellent volume which documents the latest thinking and future trends in physics research....The interdisciplinary nature of the material will make this book valuable to both veteran researchers and those new to the field." Physics in Canada Edited by Nobel Prize winner A.M. Prokhorov, these incisive essays review free-electron lasers and microwave generators in plasma physics, relativistic beam physics, radiation physics, and energy physics, as well as particle accelerators and synchrotron radiation.

First Observations of Laser-Driven Acceleration of Relativistic Electrons in a Semi-Infinite Vacuum Space

First Observations of Laser-Driven Acceleration of Relativistic Electrons in a Semi-Infinite Vacuum Space PDF Author: J. E. Spencer
Publisher:
ISBN:
Category :
Languages : en
Pages : 3

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Book Description
We have observed acceleration of relativistic electrons in vacuum driven by a linearly polarized visible laser beam incident on a thin gold-coated reflective boundary. The observed energy modulation effect follows all the characteristics expected for linear acceleration caused by a longitudinal electric field. As predicted by the Lawson-Woodward theorem the laser driven modulation only appears in the presence of the boundary. It shows a linear dependence with the strength of the electric field of the laser beam and also it is critically dependent on the laser polarization. Finally, it appears to follow the expected angular dependence of the inverse transition radiation process. experiment as the Laser Electron Accelerator Project (LEAP).

Laser-Plasma Interactions

Laser-Plasma Interactions PDF Author: Dino A. Jaroszynski
Publisher: CRC Press
ISBN: 1584887796
Category : Science
Languages : en
Pages : 454

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Book Description
A Solid Compendium of Advanced Diagnostic and Simulation ToolsExploring the most exciting and topical areas in this field, Laser-Plasma Interactions focuses on the interaction of intense laser radiation with plasma. After discussing the basic theory of the interaction of intense electromagnetic radiation fields with matter, the book covers three ap

Frontiers in High Energy Density Physics

Frontiers in High Energy Density Physics PDF Author: National Research Council
Publisher: National Academies Press
ISBN: 030908637X
Category : Science
Languages : en
Pages : 177

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Book Description
Recent scientific and technical advances have made it possible to create matter in the laboratory under conditions relevant to astrophysical systems such as supernovae and black holes. These advances will also benefit inertial confinement fusion research and the nation's nuclear weapon's program. The report describes the major research facilities on which such high energy density conditions can be achieved and lists a number of key scientific questions about high energy density physics that can be addressed by this research. Several recommendations are presented that would facilitate the development of a comprehensive strategy for realizing these research opportunities.