40 MeV proton beam generation with ultra-high intensity high-contrast Ti:sapphire laser system

Nishiuchi, Mamiko; Ogura, Koichi; Pirozhkov, A. S.; Tanimoto, Tsuyoshi*; Sagisaka, Akito*; Esirkepov, T. Z.; Kando, Masaki; Kiriyama, Hiromitsu; Shimomura, Takuya; Kondo, Shuji; Kanazawa, Shuhei; Nakai, Yoshiki*; Sasao, Hajime*; Fukuda, Yuji; Sakaki, Hironao; Kanasaki, Masato; Yogo, Akifumi; Kondo, Kiminori

We present the extension of the maximum energy of protons from the interaction between the short-pulse compact laser system and soild thin-foil target. The laser pulses with parameters of 800 nm in wavelength, 40 fs of pulse width, 7 J of energy, 10 contrast are focused onto the target with the peak intensity of more than 10 Wcm, which is also well confirmed by the measured electron temperature of 16 MeV. The Al-0.8m-thick or SUS-2.5m-thick targets are irradiated from 45 degrees incidence angle. The observation of the proton beam is conducted with CR-39 stack detector set at the rear side of the target 55 mm downstream. The direction of the higher energy protons are deflected away from the target normal direction for Al-0.8m-thick target. The most probable explanation of this is due to the deformation of the target shape caused by the ASE pedestal pulse component.