Ion acceleration based on the interaction between high power laser and cluster medium

高強度レーザーとクラスター媒質との相互作用によるイオン加速

福田 祐仁; 松井 隆太郎; 岩田 夏弥*; 岸本 泰明

Fukuda, Yuji; Matsui, Ryutaro; Iwata, Natsuyo*; Kishimoto, Yasuaki

高強度レーザーとクラスター媒質との相互作用機構を明らかにするために、原子過程と緩和過程が考慮された相対論的3次元粒子コードを用い、二酸化炭素クラスターとヘリウムガスの系に対するシミュレーション研究を行った。その結果、(1)クラスターのクーロン爆発によるイオンの加速、(2)クーロン爆発により引き起こされた背景ヘリウムガスの圧縮と加速、(3)磁気渦の発生に伴う加速電場形成、(4)シース電場の形成、が相乗的に影響しイオン加速を実現していることが明らかとなった。

In order to investigate the underlying physical mechanism of high power laser interaction with cluster medium, we have performed simulations using EPIC3D (Extended Particle based Integrated Code), which includes key atomic processes and relaxation processes self-consistently in fully relativistic three dimensional configuration, and systematically investigated the interaction processes of medium of carbon clusters embedded in helium gas. We found that the synergetic interplay of different mechanisms such as (1) acceleration of ions due to Coulomb explosion of individual carbon clusters, (2) compression and acceleration of background helium gas due to the Coulomb explosion of clusters, (3) magnetic vortex generation and associated pinching near the rare surface, and (4) sheath acceleration at the interface between the medium and vacuum, could play an important role in realizing the particle acceleration observed in the experiments.