Effects of self-focusing on tunnel-ionization-induced injection in a laser wakefield accelerator

Journal Article · Tue Nov 15 04:00:00 EST 2011 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3656958· OSTI ID:22047083

Changquan, Xia; Jiansheng, Liu; Wentao, Wang; Haiyang, Lu; Wang, Cheng; Aihua, Deng; Wentao, Li; Hui, Zhang; Xiaoyan, Liang; Yuxin, Leng; Xiaoming, Lu; Cheng, Wang; Jianzhou, Wang; Ruxin, Li; Zhizhan, Xu ^[1]; Nakajima, Kazuhisa ^[1]

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1. State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P.O. Box 800-211, Shanghai 201800 (China)

We report on the study of the self-focusing effects on the tunnel-ionization-induced injection in a laser wakefield accelerator. Targets composed of a gas mixture of 94% helium and 6% oxygen were used. The energy, energy spread, and charge of the generated electron beams can be adjusted by changing the input laser intensity and the plasma density, but the different aspects of the properties of the electron beams were not independent. It was inferred that the K-shell electrons of oxygen were ionized and injected into the plasma wake for acceleration when the laser intensity was increased beyond the threshold for generating O{sup 7+} by tunnel-ionization, due to the relativistic self-focusing in the propagation. Controlling the self-focusing of the laser beam by adjusting the input laser energy to shorten the distance over which the electrons were injected into the wake, quasi-monoenergetic electron beams were observed.

• OSTI ID: 22047083
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 11 Vol. 18; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ACCELERATION
BEAM PRODUCTION
BEAM TRANSPORT
BEAM-PLASMA SYSTEMS
ELECTRON BEAMS
HELIUM
K SHELL
LASER TARGETS
LASER-PRODUCED PLASMA
LASERS
LIGHT TRANSMISSION
OXYGEN
PLASMA DENSITY
PLASMA GUNS
RELATIVISTIC RANGE
WAKEFIELD ACCELERATORS