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Title: Effects of laser polarization in the expansion of plasma waveguides

We experimentally demonstrate that a column of hydrogen plasma generated by an ultra-short (sub-picosecond), moderate intensity (∼10{sup 15–16} W.cm{sup –2}) laser, radially expands at a higher velocity when using a circularly polarized laser beam instead of a linearly polarized beam. Interferometry shows that after 1 ns there is a clear shock structure formed, that can be approximated to a cylindrical blast wave. The shock velocity was measured for plasmas created with linearly and circularly polarized laser beams, indicating an approximately 20% higher velocity for plasmas generated with a circularly polarized laser beam, thus implying a higher plasma electron temperature. The heating mechanism was determined to be the Above Threshold Ionization effect. The calculated electrum energy spectrum for a circularly polarized laser beam was broader when compared to the one generated by a linearly polarized laser beam, leading to a higher plasma temperature.
Authors:
; ; ; ; ;  [1]
  1. GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico (IST), Universidade Técnica de Lisboa (UTL), 1049-001 Lisbon (Portugal)
Publication Date:
OSTI Identifier:
22218554
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 20; Journal Issue: 10; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; APPROXIMATIONS; COMPARATIVE EVALUATIONS; DETONATION WAVES; ELECTRON TEMPERATURE; ENERGY SPECTRA; HYDROGEN; INTERFEROMETRY; ION TEMPERATURE; IONIZATION; LASERS; PLASMA DIAGNOSTICS; PLASMA EXPANSION; PLASMA HEATING; PLASMA PRODUCTION; POLARIZATION; POLARIZED BEAMS; VELOCITY