Efficient multi-keV X-ray generation from a high-Z target irradiated with a clean ultra-short laser pulse

Zhang, Z.*; Nishikino, Masaharu; Nishimura, Hiroaki*; Kawachi, Tetsuya; Pirozhkov, A. S.; Sagisaka, Akito; Orimo, Satoshi; Ogura, Koichi; Yogo, Akifumi; Okano, Yasuaki*; Oshima, Shinsuke*; Sunahara, Atsushi*; Fujioka, Shinsuke*; Kiriyama, Hiromitsu; Kondo, Kiminori; Shimomura, Takuya; Kanazawa, Shuhei

line emission from Mo and Ag plate were experimentally studied by using ultra-high intensity, clean femtosecond laser pulses. Absolutely yield of X-rays at 17 keV from Mo and 22 keV from Ag were measured as a function of the laser pulse contrast ratio and irradiation intensity. Significant enhancement of yields were obtained for both Mo and Ag with higher contrast ratios and high irradiance. The conversion efficiencies of 4.28 10/sr for Mo and 4.84 10/sr for Ag, the highest values ever obtained, have been demonstarted with the contrast ratio of 10 to 10.