Frequency chirp and pulse shape effects in self-modulated laser wakefield accelerators

Journal Article · Thu Nov 07 04:00:00 EST 2002 · Physics of Plasmas

OSTI ID:816357

Schroeder, C B ^[1]; Esarey, E; Geddes, C G.R.; Toth, Cs; Shadwick, B A; van Tilborg, J; Faure, J; Leemans, W P

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1. LBNL Library

The effect of asymmetric laser pulses on plasma wave excitation in a self-modulated laser wakefield accelerator is examined. Laser pulse shape and frequency chirp asymmetries, controlled experimentally in the laser system through a grating pair compressor, are shown to strongly enhance measured electron yields for certain asymmetries. It is shown analytically that a positive (negative) frequency chirp enhances (suppresses) the growth rate of the Raman forward scattering and near-forward Raman sidescatter instabilities, but is of minimal importance for the experimental parameters. Temporal laser pulse shapes with fast rise times (< plasma period) are shown to generate larger wakes (compared to slow rise time pulses) which seed the growth of the plasma wave, resulting in enhanced electron yield.

• Research Organization: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: USDOE Director, Office of Science. Office of High Energy and Nuclear Physics. Division of High Energy Physics (US)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 816357
• Report Number(s): LBNL--52176
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 5 Vol. 10; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
ELECTRONS
EXCITATION
LASER PLASMA ACCELERATION RAMAN SCATTERING
LASERS
PLASMA
PLASMA WAVES
PULSE RISE TIME
SCATTERING
SEEDS
SHAPE
WAKEFIELD ACCELERATORS