Splash plasma channels produced by picosecond laser pulses in argon gas for laser wakefield acceleration

レーザー航跡場加速のための、ピコ秒レーザーパルスによる飛び散ったアルゴンプラズマチャネルの形成

水田 好雄*; 細貝 知直*; 益田 伸一*; Zhidkov, A.*; 牧戸 啓悟*; 中新 信彦*; 梶野 祥平*; 西田 明憲*; 神門 正城; 森 道昭; 小瀧 秀行; 林 由紀雄; Bulanov, S. V.; 兒玉 了祐*

Mizuta, Yoshio*; Hosokai, Tomonao*; Masuda, Shinichi*; Zhidkov, A.*; Makito, Keigo*; Nakanii, Nobuhiko*; Kajino, Shohei*; Nishida, Akinori*; Kando, Masaki; Mori, Michiaki; Kotaki, Hideyuki; Hayashi, Yukio; Bulanov, S. V.; Kodama, Ryosuke*

Laser wakefield acceleration is capable of generating electron bunches with high quality: quasi-monoenergetic, low in emittance, and a very short duration of the order of ten femto-seconds. Such femtosecond bunches can be used to measure ultrafast phenomena. We conducted experiments for controllable electron bunch generation. Short-lived, 10 ps, deep plasma channels, with their lengths of 1 mm and diameters of 20 m, are observed and characterized in Ar gas jets irradiated by moderate intensity, 10 W/cm, laser pulses with a duration from subpicosecond to several picoseconds. The channels, upon 2D particle-in-cell simulations including ionization, fit well in the guiding of high intensity femtosecond laser pulses and, therefore, in laser wakefield acceleration with a controllable electron self-injection.