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 …
Coherent Beam Combining Of Ultrashort Laser Pulses.Pdf, Ahmad Azim
Apr 2016
Coherent Beam Combining Of Ultrashort Laser Pulses.Pdf, Ahmad Azim
Ahmad Azim
In this thesis, CBC of ultrashort laser pulses is investigated based upon the method known as divided-pulse amplification (DPA). Active, passive and hybrid DPA have been achieved in a flashlamp-pumped Nd:YAG laser seeded from a Ti:sapphire mode-locked laser. Picosecond pulses at a repetition rate of 2.5 Hz were amplified and combined to record energy of 216 mJ with a combination efficiency of 80%. Engineering of the Nd:YAG amplifier chain for high-efficiency energy extraction is presented. In addition, phasing of actively divided pulses with a CW pilot laser co-propagating with the pulsed beam is also demonstrated. Analysis of multiple DPA configurations …
Controlled Generation Of Comb-Like Electron Beams In Plasma Channels For Polychromatic Inverse Thomson Gamma-Ray Sources, Serge Y. Kalmykov, X. Davoine, I Ghebregziabher, R Lehe, A F. Lifschitz, B A. Shadwick
Feb 2016
Controlled Generation Of Comb-Like Electron Beams In Plasma Channels For Polychromatic Inverse Thomson Gamma-Ray Sources, Serge Y. Kalmykov, X. Davoine, I Ghebregziabher, R Lehe, A F. Lifschitz, B A. Shadwick
Serge Youri Kalmykov
Propagating a relativistically intense, negatively chirped laser pulse (the bandwidth > 150 nm) in a plasma channel makes it possible to generate background-free, comb-like electron beams - sequences of synchronized bunches with a low phase-space volume and controlled energy spacing. The tail of the pulse, confined in the accelerator cavity (an electron density ‘bubble’), experiences periodic focusing, while the head, which is the most intense portion of the pulse, steadily self-guides. Oscillations of the cavity size cause periodic injection of electrons from the ambient plasma, creating an electron energy comb with the number of components, their mean energy, and energy …
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, …
