Quantitative Kα line spectroscopy for energy transport in ultra-intense laser plasma interaction

8th International Conference on Inertial Fusion Sciences and Applications

Zhang, Z.^1 ; Nishimura, H.^1 ; Fujioka, S.^1 ; Arikawa, Y.^1 ; Nakai, M.^1 ; Chen, H.^2 ; Park, J.^2 ; Williams, G.J.^2 ; Ozaki, T.^3 ; Shiraga, H.^1 ; Kojima, S.^1 ; Johzaki, T.^4 ; Sunahara, A.^5 ; Miyanaga, N.^1 ; Kawanaka, J.^1 ; Nakata, Y.^1 ; Jitsuno, T.^1 ; Azechi, H.^1

K Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Osaka Suita

565-0871, Japan^1

Lawrence Livermore National Laboratory, Livermore

CA

94550, United States^2

Institute for Laser Technology, 2-6 Yamada-oka, Osaka Suita

565-0871, Japan^3

Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi Hiroshima

739-8527, Japan^4

Institute for Laser Technology, 2-6 Yamadaoka, Osaka Suita

565-0871, Japan^5

关键词: Cone guided fast ignition;    Electron spectrometer;    Electron spectrum;    Energy transfer efficiency;    Experimental campaign;    Institute of laser engineerings;    Laser-plasma interactions;    Ultra-intense lasers;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/688/1/012132/pdf
DOI  :  10.1088/1742-6596/688/1/012132

来源: IOP

【 摘 要 】

Absolute Ka line spectroscopy is proposed for studying laser-plasma interactions taking place in the cone-guided fast ignition targets. X-ray spectra ranging from 20 to 100 keV were quantitatively measured with a Laue spectrometer. The absolute sensitivities of the Laue spectrometer system were calibrated using pre-characterized laser-produced x-ray sources and radioisotopes. The integrated reflectivity for the crystal is in good agreement with predictions by an open code for x-ray diffraction. The energy transfer efficiency from incident laser beams to hot electrons, as the energy transfer agency, is derived as a consequence of this work. The absolute yield of Au and Ta Ka lines were measured in the fast ignition experimental campaign performed at Institute of Laser Engineering, Osaka University. Applying the hot electron spectrum information from the electron spectrometer, an energy transfer efficiency of the incident LFEX [1], a kJ-class PW laser, to hot electrons was derived for a planar and cone-guided geometry.