Angular distribution and conversion of multi-keV L-shell X-ray sources produced from nanosecond laser irradiated thick-foil targets
Data(s) |
2008
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Resumo |
An experimental study on the angular distribution and conversion of multi-keV X-ray sources produced from 2 ns-duration 527nm laser irradiated thick-foil targets on Shenguang II laser facility (SG-II) is reported. The angular distributions measured in front of the targets can be fitted with the function of f(theta) = alpha+ (1- alpha)cos(beta) theta (theta is the viewing angle relative to the target normal), where alpha = 0.41 +/- 0.014, beta = 0.77 +/- 0.04 for Ti K-shell X-ray Sources (similar to 4.75 keV for Ti K-shell), and alpha = 0.085 +/- 0.06, beta = 0.59 +/- 0.07 for Ag/Pd/Mo L-shell X-ray Sources (2-2.8 keV for Mo L-shell, 2.8-3.5 keV for Pd L-shell, and 3-3.8 keV for Ag L-shell). The isotropy of the angular-distribution of L-shell emission is worse than that of the K-shell emission at larger viewing angle (>70 degrees), due to its larger optical depth (stronger self-absorption) in the cold plasma side lobe Surrounding the central emission region, and in the central hot plasma region (emission region). There is no observable difference in the angular distributions of the L-shell X-ray emission among Ag, Pd, and Mo. The conversion efficiency of Ag/Pd/Mo L-shell X-ray sources is higher than that of the Ti K-shell X-ray sources, but the gain relative to the K-shell emission is not as high as that by using short pulse lasers. The conversion efficiency of the L-shell X-ray sources decrease, with increasing atomic numbers (or X-ray photon energy), similar to the behavior of the K-shell X-ray Source. National High Technology Programs on Inertial Confinement Fusion ; Science and Technology Development Fund of CAEP [2007B08003]; National Natural Science Foundation of China [10375064, 10625523, 10775165]; National Basic Research Program of China [2006CB8 |
Identificador | |
Idioma(s) |
英语 |
Fonte |
Hu G. -Y.;Zhang J. -Y.;Zheng J.;沈百飞;Liu S. -Y.;Yang J. -M.;Ding Y. -K.;Hu X.;Huang Y. -X.;Du H. -B.;Yi R. -Q.;Lei A. -L.;Xu Z. -Z..,Laser Part. Beams,2008,26(4):661-670 |
Palavras-Chave | #Angular distribution #Laser plasma #X-ray source |
Tipo |
期刊论文 |