Novel path towards compact laser ion accelerators for hadron therapy; Tenfold energy increase in laser-driven multi-MeV ion generation using a cluster-gas target

Fukuda, Yuji; Faenov, A. Y.; Tampo, Motonobu; Pikuz, T.*; Nakamura, Tatsufumi; Kando, Masaki; Hayashi, Yukio; Yogo, Akifumi; Sakaki, Hironao; Kawase, Keigo; Pirozhkov, A. S.; Ogura, Koichi; Mori, Michiaki; Esirkepov, T. Z.; Koga, J. K.; Boldarev, A.*; Gasilov, V.*; Magunov, A.*; Kodama, Ryosuke*; Yamauchi, Tomoya*; Bolton, P.; Kato, Yoshiaki ; Tajima, Toshiki; Daido, Hiroyuki; Bulanov, S. V.

We demonstrate generation of 10-20 MeV/u ions with a compact 4 TW laser using a gas target mixed with submicron clusters, corresponding to tenfold increase in the ion energies compared to previous experiments with solid targets. It is inferred that the high energy ions are generated due to formation of a strong dipole vortex structure. The demonstrated method has a potential to construct compact and high repetition rate ion sources for hadron therapy and other applications.