X-ray Polarization Spectroscopy from Ultra-Intense
Authors: Booth N., Clarke R., Gallegos P., Gizzi LA., Gregori G., Koester P., Labate L., Levato T., Li B., Makita M., Pasley J., Rajeev P.P., Riley D., Wagenaars E., Waugh J.N., Woolsey N.C.
Autors Affiliation: Department of Physics, University of York, Heslington, York, UK, YO10 5DD;
Department of Physics, University of Oxford, UK, OX4 1PJ;
ILIL-IPCF, Consiglio Nazionale delle Ricerche, and INFN, PISA, Italy;
Central Laser Facility, STFC Rutherford Appleton Laboratory, Didcot, UK, OX11 0QN;
Department of Physics and Mathematics, Queens University Belfast, Belfast, UK, BT1 4NN
Abstract: Detailed knowledge of fast electron energy transport following the interaction of ultrashort intense laser pulses is a key subject for fast ignition. This is a problem relevant to many areas of laser-plasma physics with particular importance to fast ignition and X-ray secondary source development, necessary for the development of large-scale facilities such as HiPER and ELI. Operating two orthogonal crystal spectrometers set at Bragg angles close to 45° determines the X-ray s- and p- polarization ratio. From this ratio, it is possible to infer the velocity distribution function of the fast electron beam within the dense plasma. We report on results of polarization measurements at high density for sulphur and nickel buried layer targets in the high intensity range of 1019 – 1021 Wcm-2. We observe at 45° the Ly-± doublet using two sets of orthogonal highly-orientated pyrolytic graphite (HOPG) crystals set in 1st order for sulphur and 3rd order for nickel.
Conference title: 6th International Conference on Inertial Fusion Sciences and Applications
Place: San Francisco, CA SEP 06-11, 2009
More Information: Pubblicato in : Journal of Physics: Conference Series 244 (2010) 022028
KeyWords: plasma; ignition;