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Full-Text Articles in Plasma and Beam Physics

Femtosecond Pulse Trains Of Polychromatic Inverse Compton Γ-Rays From Designer Electron Beams Produced By Laser-Plasma Acceleration In Plasma Channels, Serge Y. Kalmykov, Isaac Ghebregziabher, X. Davoine, Remi Lehe, Agustin F. Lifschitz, Victor Malka, Bradley A. Shadwick Oct 2016

Femtosecond Pulse Trains Of Polychromatic Inverse Compton Γ-Rays From Designer Electron Beams Produced By Laser-Plasma Acceleration In Plasma Channels, Serge Y. Kalmykov, Isaac Ghebregziabher, X. Davoine, Remi Lehe, Agustin F. Lifschitz, Victor Malka, Bradley A. Shadwick

Serge Youri Kalmykov

Propagating a short, relativistically intense laser pulse in a plasma channel makes it possible to generate clean comb-like electron beams – sequences of synchronized, low phase-space volume bunches with controllable energy spacing [S. Y. Kalmykov et al., “Accordion Effect Revisited: Generation of Comb-Like Electron Beams in Plasma Channels,” in Advanced Accelerator Concepts: 16th Workshop, AIP Conference Proceedings; this volume]. All-optical control of the electron beam phase space structure via manipulation of the drive pulse phase (negative chirp) and parameters of the channel enables the design of a tunable, all-optical source of polychromatic pulsed gamma-rays using the mechanism of inverse Compton …


Accordion Effect Revisited: Generation Of Comb-Like Electron Beams In Plasma Channels, Serge Y. Kalmykov, X. Davoine, Remi Lehe, Agustin F. Lifschitz, Bradley A. Shadwick Oct 2016

Accordion Effect Revisited: Generation Of Comb-Like Electron Beams In Plasma Channels, Serge Y. Kalmykov, X. Davoine, Remi Lehe, Agustin F. Lifschitz, Bradley A. Shadwick

Serge Youri Kalmykov

Propagating a short, relativistically intense laser pulse in a plasma channel makes it possible to generate comb-like electron beams – sequences of synchronized, low phase-space volume bunches with controllable energy difference. The tail of the pulse, confined in the accelerator cavity (electron density “bubble”), transversely flaps, as the pulse head steadily self-guides. The resulting oscillations of the cavity size cause periodic injection of electrons from ambient plasma, creating an energy comb with the number of components, their energy, and energy separation dependent on the channel radius and pulse length. Accumulation of noise (continuously injected charge) can be prevented using a …


Customizable Electron Beams From Optically Controlled Laser Plasma Acceleration For Γ-Ray Sources Based On Inverse Thomson Scattering, Serge Y. Kalmykov, X. Davoine, Isaac Ghebregziabher, Bradley A. Shadwick Jan 2016

Customizable Electron Beams From Optically Controlled Laser Plasma Acceleration For Γ-Ray Sources Based On Inverse Thomson Scattering, Serge Y. Kalmykov, X. Davoine, Isaac Ghebregziabher, Bradley A. Shadwick

Serge Youri Kalmykov

Laser wakefield acceleration of electrons in the blowout regime can be controlled by tailoring the laser pulse phase and the plasma target. The100nm-scale bandwidth and negative frequency chirp of the optical driver compensate for the nonlinear frequency red-shift imparted by wakefield excitation.This mitigates pulse self-steepening and suppresses continuous injection. The plasma channel suppresses diffraction of the pulse leading edge, further reducing self-steepening, making injection even quieter. Besides, the channel destabilizes the pulse tail confined within the accelerator cavity (the electron density “bubble”), causing oscillations in the bubble size. The resulting periodic injection generates background-free comb-like beams – sequences of synchronized, …


Control And Optimization Of A Staged Laser-Wakefield Accelerator, Grigory V. Golovin, Sudeep Banerjee, Shouyuan Chen, Nathan D. Powers, Cheng Liu, Wenchao Yan, Jia Zhang, Ping Zhang, Baozhen Zhao, Donald Umstadter Jan 2016

Control And Optimization Of A Staged Laser-Wakefield Accelerator, Grigory V. Golovin, Sudeep Banerjee, Shouyuan Chen, Nathan D. Powers, Cheng Liu, Wenchao Yan, Jia Zhang, Ping Zhang, Baozhen Zhao, Donald Umstadter

Donald Umstadter Publications

We report results of an experimental study of laser-wakefield acceleration of electrons, using a staged device based on a double-jet gas target that enables independent injection and acceleration stages. This novel scheme is shown to produce stable, quasi-monoenergetic, and tunable electron beams. We show that optimal accelerator performance is achieved by systematic variation of five critical parameters. For the injection stage, we show that the amount of trapped charge is controlled by the gas density, composition, and laser power. For the acceleration stage, the gas density and the length of the jet are found to determine the final electron energy. …