Experimental evidence of nonthermal acceleration of relativistic electrons by an intensive laser pulse

Kuramitsu, Yasuhiro*; Nakanii, Nobuhiko*; Kondo, Kiminori; Sakawa, Yoichi*; Mori, Yoshitaka*; Miura, Eisuke*; Tsuji, Kazuki*; Kimura, Kazuya*; Fukumochi, Shuji*; Kashihara, Mamoru*; Tanimoto, Tsuyoshi; Nakamura, Hirotaka*; Ishikura, Takahiko*; Takeda, Kazuo*; Tampo, Motonobu; Kodama, Ryosuke*; Kitagawa, Yoneyoshi*; Mima, Kunioki*; Tanaka, Kazuo*; Hoshino, Masahiro*; Takabe, Hideaki*

An energy distribution function of energetic particles in the universe or cosmic rays is well represented by a power-law spectrum, therefore, nonthermal acceleration is essential to understand the origin of cosmic rays. A possible candidate for the origin of cosmic rays is wakefield acceleration at relativistic astrophysical perpendicular shocks. Substituting an intensive laser pulse for the large amplitude light waves, we performed a model experiment of the shock environments in a laboratory plasma.