FEL2017 - List of Authors (Gover, A.)

Paper	Title	Page
TUC04	Enhancement of Radiative Energy Extraction in an FEL Oscillator by Post-Saturation Beam Energy Ramping	244
	H. S. Marks, A. Gover University of Tel-Aviv, Faculty of Engineering, Tel-Aviv, Israel E. Dyunin, Yu. Lurie Ariel University, Ariel, Israel
	We present experimental results showing a greater than 50% increase in post-saturation radiation power extraction from a Free Electron Laser oscillator based on an electrostatic accelerator. Electrostatic accelerator free electron laser oscillators have the potential for CW operation. Present day operating oscillators rely on long pulses of electrons, tens of microseconds in duration; they generate correspondingly long radiation pulses, at a single longitudinal mode after a mode competition process. The presented post-saturation power extraction enhancement process is based on temporal tapering (up-ramping) of the beam energy, enabling a large synchrotron oscillation swing of the trapped electron bunches in passage along the interaction length. We further discuss the theoretical limits of the temporal tapering efficiency enhancement process.
	Slides TUC04 [2.647 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-TUC04
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FRB03	Dynamics of Superradiant Emission by a Prebunched E-Beam and its Spontaneous Emission Self-Interaction	572
	R. Ianconescu, A. Gover University of Tel-Aviv, Faculty of Engineering, Tel-Aviv, Israel C. Emma, P. Musumeci UCLA, Los Angeles, USA A. Friedman Ariel University, Ariel, Israel
	Funding: Partial support by US-Israel Binational Science Foundation (BSF) and by Deutsche-Israelische Projektkooperation (DIP). In the context of radiation emission from an electron beam, Dicke's superradiance (SR) is the enhanced coherent spontaneous radiation emission from a prebunched beam, and Stimulated-Superradiance (ST-SR) is the further enhanced emission of the bunched beam in the presence of a phase-matched radiation wave.* These processes are analyzed for undulator radiation in the framework of radiation field mode-excitation theory. In the nonlinear saturation regime the synchronicity of the bunched beam and an injected radiation wave may be sustained by wiggler tapering: Tapering-Enhanced Superradiance (TES) and Tapering-Enhanced Stimulated Superradiance Amplification (TESSA). Identifying these processes is useful for understanding the enhancement of radiative emission in the tapered wiggler section of seeded FELs.,*** The nonlinear formulation of the energy transfer dynamics between the radiation wave and the bunched beam fully conserves energy. This includes conservation of energy without radiation reaction terms in the interesting case of spontaneous self-interaction (no input radiation). * A. Gover, Phys. Rev. ST-AB 8, 030701 (2005). J. Duris et al., New J.Phys. 17 063036 (2015). * E. A. Schneidmiller et al., PRST-AB 18, 03070 (2015). **** C. Emma et al., this conference.
	Slides FRB03 [1.437 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-FRB03
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Enhancement of Radiative Energy Extraction in an FEL Oscillator by Post-Saturation Beam Energy Ramping

244

H. S. Marks, A. Gover
University of Tel-Aviv, Faculty of Engineering, Tel-Aviv, Israel
E. Dyunin, Yu. Lurie
Ariel University, Ariel, Israel

We present experimental results showing a greater than 50% increase in post-saturation radiation power extraction from a Free Electron Laser oscillator based on an electrostatic accelerator. Electrostatic accelerator free electron laser oscillators have the potential for CW operation. Present day operating oscillators rely on long pulses of electrons, tens of microseconds in duration; they generate correspondingly long radiation pulses, at a single longitudinal mode after a mode competition process. The presented post-saturation power extraction enhancement process is based on temporal tapering (up-ramping) of the beam energy, enabling a large synchrotron oscillation swing of the trapped electron bunches in passage along the interaction length. We further discuss the theoretical limits of the temporal tapering efficiency enhancement process.

Slides TUC04 [2.647 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-TUC04

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FRB03

Dynamics of Superradiant Emission by a Prebunched E-Beam and its Spontaneous Emission Self-Interaction

572

R. Ianconescu, A. Gover
University of Tel-Aviv, Faculty of Engineering, Tel-Aviv, Israel
C. Emma, P. Musumeci
UCLA, Los Angeles, USA
A. Friedman
Ariel University, Ariel, Israel

Funding: Partial support by US-Israel Binational Science Foundation (BSF) and by Deutsche-Israelische Projektkooperation (DIP).
In the context of radiation emission from an electron beam, Dicke's superradiance (SR) is the enhanced coherent spontaneous radiation emission from a prebunched beam, and Stimulated-Superradiance (ST-SR) is the further enhanced emission of the bunched beam in the presence of a phase-matched radiation wave.* These processes are analyzed for undulator radiation in the framework of radiation field mode-excitation theory. In the nonlinear saturation regime the synchronicity of the bunched beam and an injected radiation wave may be sustained by wiggler tapering: Tapering-Enhanced Superradiance (TES) and Tapering-Enhanced Stimulated Superradiance Amplification (TESSA).** Identifying these processes is useful for understanding the enhancement of radiative emission in the tapered wiggler section of seeded FELs.***,**** The nonlinear formulation of the energy transfer dynamics between the radiation wave and the bunched beam fully conserves energy. This includes conservation of energy without radiation reaction terms in the interesting case of spontaneous self-interaction (no input radiation).
* A. Gover, Phys. Rev. ST-AB 8, 030701 (2005).
** J. Duris et al., New J.Phys. 17 063036 (2015).
*** E. A. Schneidmiller et al., PRST-AB 18, 03070 (2015).
**** C. Emma et al., this conference.

Slides FRB03 [1.437 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-FRB03

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)