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Title: Combined role of frequency variation and magnetic field on laser electron acceleration

Abstract

Laser-induced acceleration of an electron injected initially at an angle to the direction of a short laser pulse with frequency variation in the presence of an axial static magnetic field has been investigated. Due to the combined effect of frequency variation of the laser and a magnetic field, the electron escapes from the laser pulse near the pulse peak. The electron gains considerable energy and retains it even after passing of the laser pulse in the presence of magnetic field in vacuum. The frequency variation plays an important role to enhance the electron energy in the presence of a static magnetic field in vacuum.

Authors:
;  [1]
  1. Center for Advanced Accelerators, Korea Electrotechnology Research Institute, Changwon 641-120 (Korea, Republic of)
Publication Date:
OSTI Identifier:
20782468
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 13; Journal Issue: 1; Other Information: DOI: 10.1063/1.2164809; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ACCELERATION; ELECTRONS; GAIN; LASERS; LIGHT TRANSMISSION; MAGNETIC FIELDS; PLASMA; PLASMA GUNS; PULSES; VARIATIONS

Citation Formats

Gupta, D.N., and Suk, H. Combined role of frequency variation and magnetic field on laser electron acceleration. United States: N. p., 2006. Web. doi:10.1063/1.2164809.
Gupta, D.N., & Suk, H. Combined role of frequency variation and magnetic field on laser electron acceleration. United States. doi:10.1063/1.2164809.
Gupta, D.N., and Suk, H. Sun . "Combined role of frequency variation and magnetic field on laser electron acceleration". United States. doi:10.1063/1.2164809.
@article{osti_20782468,
title = {Combined role of frequency variation and magnetic field on laser electron acceleration},
author = {Gupta, D.N. and Suk, H.},
abstractNote = {Laser-induced acceleration of an electron injected initially at an angle to the direction of a short laser pulse with frequency variation in the presence of an axial static magnetic field has been investigated. Due to the combined effect of frequency variation of the laser and a magnetic field, the electron escapes from the laser pulse near the pulse peak. The electron gains considerable energy and retains it even after passing of the laser pulse in the presence of magnetic field in vacuum. The frequency variation plays an important role to enhance the electron energy in the presence of a static magnetic field in vacuum.},
doi = {10.1063/1.2164809},
journal = {Physics of Plasmas},
number = 1,
volume = 13,
place = {United States},
year = {Sun Jan 15 00:00:00 EST 2006},
month = {Sun Jan 15 00:00:00 EST 2006}
}
  • The investigation [Gupta et al., Appl. Phys. Lett. 91, 211101 (2007)] for electron acceleration by a tightly focused laser beam is revisited by including the effect of laser frequency chirping. The frequency chirping plays an important role to enhance the electron energy if the laser is tightly focused. Due to the combined effect of frequency chirping and tight focusing of a laser beam, an electron can be accelerated for a longer time in vacuum. As a result, from the proposed investigation, the electron energy gain during the laser acceleration is found to be considerably higher.
  • Interaction of electrons with a focused laser field combined with a static magnetic field is considered. Gain of the energy acquired by the electron after crossing the laser focus is found. Optimal conditions for efficient acceleration of electrons are determined. Efficiency of acceleration is shown to be maximal in the case of almost, but not exactly, coinciding directions of a static magnetic field and of propagation of the laser radiation (almost collinear geometry). A small optimal angle between these two directions is shown to be of the order of inverse relativistic factor 1/y. An optimal ratio of the transverse tomore » longitudinal electron energy in a static magnetic field and optimal conditions of light focusing are found. The optimized electron energy gain {Delta}{epsilon}{sub opt} is shown to be a linear function of y. In this paper it is shown that {Delta}{epsilon}{sub 0pt} can be rather large at moderately high intensity of the laser radiation in the focus.« less
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  • Electron bunch acceleration by a laser pulse having Gaussian radial and temporal profiles of intensity has been studied numerically in a static helical magnetic wiggler in vacuum. The main electron bunch parameters for simulations are 10 MeV initial energy with 0.1% longitudinal energy spread, 1 mm mrad rms transverse emittance, and 3x10{sup 12} cm{sup -3} density. It is shown that the radial Gaussian profile can decrease the acceleration gradient compared with that of the plane-wave approximation due to the reduction of electron-pulse interaction area. In order to collimate electron bunch and overcome the decreasing of the acceleration gradient, an externalmore » axial magnetic field is used. The importance of the electron initial phase with respect to laser pulse is considered, and some appropriate values are found. Finally, acceleration of a femtosecond (fs) microbunch with an optimum appropriate initial phase is considered, which leads to a nearly monoenergetic microbunch and an acceleration gradient of about {approx_equal}0.2 GeV/m.« less
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