Xe K-shell X-ray generation using conical nozzle and 25 TW laser

Hayashi, Yukio; Pirozhkov, A. S.; Kando, Masaki; Ogura, Koichi; Kotaki, Hideyuki; Kiriyama, Hiromitsu; Okada, Hajime; Goto, Hideki*; Nishikawa, Tadashi*

To increase X-ray photon number generated by laser-cluster interaction, it is important to understand the dependence of X-ray generation on cluster size. We carried out Xe K-shell X-ray generation using a conical nozzle with Xe clusters, the radius of which was controllable by adjusting the backing pressure. The experiment clarifies the result that the Xe K-shell X-ray photon number increases with increasing cluster radius from 8 to 12 nm, and saturates at the radius between 12 and 17 nm. We also investigated the Xe K-shell X-ray photon number dependence on laser intensity, and found that the threshold laser intensity of the Xe K-shell X-ray generation exists between 210 and 510 W/cm.