Author: CLAUDIO EMMA
Publisher:
ISBN:
Category :
Languages : en
Pages : 193
Book Description
The advent of the X-ray Free Electron Laser (XFEL) as the world's brightest light source has opened the door to the study of natural phenomena occurring on Angstrom level spatial scales and femtosecond time intervals. After more than five years of successful operation, there is a demand from the scientific community to further increase the brightness and peak power one hundred times more than the state-of-the art to reach TW power X-ray pulses in the next generation of XFELs. The central subject of this dissertation is the study of strategies to achieve high efficiency, high power XFEL pulses via optimized undulator tapering and the novel technique of fresh bunch self-seeding which we demonstrate experimentally in this work. Our work begins with theoretical and numerical investigations of high efficiency XFELs in which we determine the primary factors which prevent the efficiency from reaching values on the order of 10 %, which correspond to TW-power pulses. The initial studies focus on the dependence of the peak power of a TW-level self-seeded tapered XFEL on the transverse electron distribution. We show via numerical simulations that more uniform transverse distributions (parabolic or flat) can increase the efficiency compared to transversely Gaussian beams from 2.8 % to 4.8 %, corresponding to an increase in peak power from 1.6 TW to 2.6 TW in a 200 m undulator. These numerical studies emphasize the contribution of two physical phenomena, diffraction and the synchrotron sideband instability, as the primary obstacles to reaching TW peak power in a compact undulator system. To circumvent these issues we propose two improvements for high extraction efficiency tapered XFELs: a new development in FEL hardware through the proposal of an Advanced Gradient Undulator (AGU), and a new technique for the efficient generation of high power XFEL radiation which we name fresh bunch self-seeding. We analyze in detail the performance of a high efficiency AGU by carrying out the first dedicated comparative numerical optimization study of a tapered FEL including and intentionally disabling time dependent effects. Combining the AGU design with an optimized undulator taper and a fresh bunch self-seeded system yields a peak efficiency in simulation of 12 % with 6.3 TW of peak power in a 100 m undulator. Following the numerical and theoretical studies of tapered XFELs, the remainder of the work describes the first experimental demonstration of fresh bunch self seeding in an XFEL. With this scheme we are able to generate high power (50 GW) narrow bandwidth ($\delta \omega/\omega_0=8\times 10^{-5}$) short X-ray pulses ($\delta t
High Efficiency, High Brightness X-ray Free Electron Laser Pulses Via Fresh Bunch Self-seeding and Undulator Tapering
Author: CLAUDIO EMMA
Publisher:
ISBN:
Category :
Languages : en
Pages : 193
Book Description
The advent of the X-ray Free Electron Laser (XFEL) as the world's brightest light source has opened the door to the study of natural phenomena occurring on Angstrom level spatial scales and femtosecond time intervals. After more than five years of successful operation, there is a demand from the scientific community to further increase the brightness and peak power one hundred times more than the state-of-the art to reach TW power X-ray pulses in the next generation of XFELs. The central subject of this dissertation is the study of strategies to achieve high efficiency, high power XFEL pulses via optimized undulator tapering and the novel technique of fresh bunch self-seeding which we demonstrate experimentally in this work. Our work begins with theoretical and numerical investigations of high efficiency XFELs in which we determine the primary factors which prevent the efficiency from reaching values on the order of 10 %, which correspond to TW-power pulses. The initial studies focus on the dependence of the peak power of a TW-level self-seeded tapered XFEL on the transverse electron distribution. We show via numerical simulations that more uniform transverse distributions (parabolic or flat) can increase the efficiency compared to transversely Gaussian beams from 2.8 % to 4.8 %, corresponding to an increase in peak power from 1.6 TW to 2.6 TW in a 200 m undulator. These numerical studies emphasize the contribution of two physical phenomena, diffraction and the synchrotron sideband instability, as the primary obstacles to reaching TW peak power in a compact undulator system. To circumvent these issues we propose two improvements for high extraction efficiency tapered XFELs: a new development in FEL hardware through the proposal of an Advanced Gradient Undulator (AGU), and a new technique for the efficient generation of high power XFEL radiation which we name fresh bunch self-seeding. We analyze in detail the performance of a high efficiency AGU by carrying out the first dedicated comparative numerical optimization study of a tapered FEL including and intentionally disabling time dependent effects. Combining the AGU design with an optimized undulator taper and a fresh bunch self-seeded system yields a peak efficiency in simulation of 12 % with 6.3 TW of peak power in a 100 m undulator. Following the numerical and theoretical studies of tapered XFELs, the remainder of the work describes the first experimental demonstration of fresh bunch self seeding in an XFEL. With this scheme we are able to generate high power (50 GW) narrow bandwidth ($\delta \omega/\omega_0=8\times 10^{-5}$) short X-ray pulses ($\delta t
Publisher:
ISBN:
Category :
Languages : en
Pages : 193
Book Description
The advent of the X-ray Free Electron Laser (XFEL) as the world's brightest light source has opened the door to the study of natural phenomena occurring on Angstrom level spatial scales and femtosecond time intervals. After more than five years of successful operation, there is a demand from the scientific community to further increase the brightness and peak power one hundred times more than the state-of-the art to reach TW power X-ray pulses in the next generation of XFELs. The central subject of this dissertation is the study of strategies to achieve high efficiency, high power XFEL pulses via optimized undulator tapering and the novel technique of fresh bunch self-seeding which we demonstrate experimentally in this work. Our work begins with theoretical and numerical investigations of high efficiency XFELs in which we determine the primary factors which prevent the efficiency from reaching values on the order of 10 %, which correspond to TW-power pulses. The initial studies focus on the dependence of the peak power of a TW-level self-seeded tapered XFEL on the transverse electron distribution. We show via numerical simulations that more uniform transverse distributions (parabolic or flat) can increase the efficiency compared to transversely Gaussian beams from 2.8 % to 4.8 %, corresponding to an increase in peak power from 1.6 TW to 2.6 TW in a 200 m undulator. These numerical studies emphasize the contribution of two physical phenomena, diffraction and the synchrotron sideband instability, as the primary obstacles to reaching TW peak power in a compact undulator system. To circumvent these issues we propose two improvements for high extraction efficiency tapered XFELs: a new development in FEL hardware through the proposal of an Advanced Gradient Undulator (AGU), and a new technique for the efficient generation of high power XFEL radiation which we name fresh bunch self-seeding. We analyze in detail the performance of a high efficiency AGU by carrying out the first dedicated comparative numerical optimization study of a tapered FEL including and intentionally disabling time dependent effects. Combining the AGU design with an optimized undulator taper and a fresh bunch self-seeded system yields a peak efficiency in simulation of 12 % with 6.3 TW of peak power in a 100 m undulator. Following the numerical and theoretical studies of tapered XFELs, the remainder of the work describes the first experimental demonstration of fresh bunch self seeding in an XFEL. With this scheme we are able to generate high power (50 GW) narrow bandwidth ($\delta \omega/\omega_0=8\times 10^{-5}$) short X-ray pulses ($\delta t
Global developments towards continuous-wave free-electron lasers
Author: Ye Chen
Publisher: Frontiers Media SA
ISBN: 2832538657
Category : Science
Languages : en
Pages : 133
Book Description
Publisher: Frontiers Media SA
ISBN: 2832538657
Category : Science
Languages : en
Pages : 133
Book Description
Pulse Propagation in Free-electron Lasers with a Tapered Undulator
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The one-dimensional theory of short pulse propagation in free electron lasers is extended to tapered undulator devices and is used to study the behavior of an oscillator with parameter values close to those expected in forthcoming experiments. It is found that stable laser output is possible only over a small range of optical cavity lengths. Optical pulse characteristics are presented and are found to change considerably over this range.
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The one-dimensional theory of short pulse propagation in free electron lasers is extended to tapered undulator devices and is used to study the behavior of an oscillator with parameter values close to those expected in forthcoming experiments. It is found that stable laser output is possible only over a small range of optical cavity lengths. Optical pulse characteristics are presented and are found to change considerably over this range.
Free-Electron Lasers in the Ultraviolet and X-Ray Regime
Author: Peter Schmüser
Publisher: Springer
ISBN: 3319040812
Category : Science
Languages : en
Pages : 240
Book Description
The main goal of the book is to provide a systematic and didactic approach to the physics and technology of free-electron lasers. Numerous figures are used for illustrating the underlying ideas and concepts and links to other fields of physics are provided. After an introduction to undulator radiation and the low-gain FEL, the one-dimensional theory of the high-gain FEL is developed in a systematic way. Particular emphasis is put on explaining and justifying the various assumptions and approximations that are needed to obtain the differential and integral equations governing the FEL dynamics. Analytical and numerical solutions are presented and important FEL parameters are defined, such as gain length, FEL bandwidth and saturation power. One of the most important features of a high-gain FEL, the formation of microbunches, is studied at length. The increase of gain length due to beam energy spread, space charge forces, and three-dimensional effects such as betatron oscillations and optical diffraction is analyzed. The mechanism of Self-Amplified Spontaneous Emission is described theoretically and illustrated with numerous experimental results. Various methods of FEL seeding by coherent external radiation are introduced, together with experimental results. The world’s first soft X-ray FEL, the user facility FLASH at DESY, is described in some detail to give an impression of the complexity of such an accelerator-based light source. The last chapter is devoted to the new hard X-ray FELs which generate extremely intense radiation in the Angstrøm regime. The appendices contain supplementary material and more involved calculations.
Publisher: Springer
ISBN: 3319040812
Category : Science
Languages : en
Pages : 240
Book Description
The main goal of the book is to provide a systematic and didactic approach to the physics and technology of free-electron lasers. Numerous figures are used for illustrating the underlying ideas and concepts and links to other fields of physics are provided. After an introduction to undulator radiation and the low-gain FEL, the one-dimensional theory of the high-gain FEL is developed in a systematic way. Particular emphasis is put on explaining and justifying the various assumptions and approximations that are needed to obtain the differential and integral equations governing the FEL dynamics. Analytical and numerical solutions are presented and important FEL parameters are defined, such as gain length, FEL bandwidth and saturation power. One of the most important features of a high-gain FEL, the formation of microbunches, is studied at length. The increase of gain length due to beam energy spread, space charge forces, and three-dimensional effects such as betatron oscillations and optical diffraction is analyzed. The mechanism of Self-Amplified Spontaneous Emission is described theoretically and illustrated with numerous experimental results. Various methods of FEL seeding by coherent external radiation are introduced, together with experimental results. The world’s first soft X-ray FEL, the user facility FLASH at DESY, is described in some detail to give an impression of the complexity of such an accelerator-based light source. The last chapter is devoted to the new hard X-ray FELs which generate extremely intense radiation in the Angstrøm regime. The appendices contain supplementary material and more involved calculations.
The Principle and Design of a High-efficiency Free-electron Laser
Author: Adrian Hsiu-Tze Ho
Publisher:
ISBN:
Category :
Languages : en
Pages : 226
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 226
Book Description
The Theory and Design of a Chirped-pulse Inverse Free-electron Laser
Author: Anthony Lawrence Troha
Publisher:
ISBN:
Category :
Languages : en
Pages : 762
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 762
Book Description
Efficiency Enhancement and Sideband Spectra of a Raman Free Electron Laser Oscillator with a "tapered" Undulator
Author: Fu Goul Yee
Publisher:
ISBN:
Category :
Languages : en
Pages : 168
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 168
Book Description
Physics Briefs
Author:
Publisher:
ISBN:
Category : Physics
Languages : en
Pages : 1288
Book Description
Publisher:
ISBN:
Category : Physics
Languages : en
Pages : 1288
Book Description
Transverse Pulse Shaping and Optimization of a Tapered Hard X-ray Free Electron Laser
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Towards a Free-electron-laser Driven by High-brightness and Low-emittance Electron Bunches
Author: Gregor Hurtig
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description