Polarized He{sub a}lpha Radiation by Anisotropic Fast Electron Transport in Ultra-Intense Laser Produced Plasmas
- Department of Energy Sciences, Tokyo Institute of Technology (Japan)
- Institute of Laser Engineering, Osaka University (Japan)
- School of Medicine, Kitasato University (Japan)
- Department of Applied Physics, University of Miyazaki (Japan)
- University of Milano, Bicocca (Italy)
- CELIA Universite de Bordeaux 1/CNRS/CEA, Talence (France)
- CENBG Universite de Bordeaux 1/CNRS-IN2P3, Gradignan (France)
- CEA/CESTA Le BARP (France)
- CEA-DAM Ile de France, Bruyres-le-Chtel (France)
In fast ignition research, the transport dynamics of fast electrons is one of the critical issues. Fast electrons generated by an intense laser pulse show a highly anisotropic velocity distribution. To gain insight into the anisotropy of the velocity distribution of fast electrons, polarized x-ray spectroscopy has been proposed. The polarization spectroscopy of Cl He{sub a}lpha radiation was experimentally demonstrated at 10{sup 17} W/cm{sup 2}(approx100 mJ in 130 fs), and a new time-dependent atomic population kinetics code was also developed. It predicts that the high polarization arises only in a low-density region of the target plasma. Additional x-ray polarization measurements were done at 10{sup 1717-18} W/cm{sup 2}(approx10 J in approx1 ps). Polarization was measured as a function of the overcoat thickness of a target. The polarization is negative in the shallow region near the target surface, and becomes near zero at the laser intensity of approx10{sup 18} W/cm{sup 2}. At approx10{sup 17} W/cm{sup 2}, the polarization varies from negative to positive, and finally zero along with an increase in the overcoat thickness.
- OSTI ID:
- 21344621
- Journal Information:
- AIP Conference Proceedings, Vol. 1161, Issue 1; Conference: 16. international conference on atomic processes in plasmas, Monterey, CA (United States), 22-26 Mar 2009; Other Information: DOI: 10.1063/1.3241198; (c) 2009 American Institute of Physics; ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Study of plasma heating induced by fast electrons
Temperature scaling of hot electrons produced by a tightly focused relativistic-intensity laser at 0.5 kHz repetition rate
Related Subjects
ANISOTROPY
CHARGED-PARTICLE TRANSPORT
COMPUTERIZED SIMULATION
ELECTRONS
GAIN
LASER TARGETS
LASER-PRODUCED PLASMA
PLASMA DENSITY
PLASMA DIAGNOSTICS
PLASMA SIMULATION
POLARIZATION
PULSED IRRADIATION
THERMONUCLEAR IGNITION
X-RAY SPECTROSCOPY
AMPLIFICATION
ELEMENTARY PARTICLES
FERMIONS
IRRADIATION
LEPTONS
PLASMA
RADIATION TRANSPORT
SIMULATION
SPECTROSCOPY
TARGETS