@misc{oai:repo.qst.go.jp:00075852,
 author = {岸本, 泰明 and 松井, 隆太郎 and 今寺, 賢志 and 坂口, 浩司 and 深見, 一弘 and 福田, 祐仁 and Fukuda, Yuuji},
 month = {Jun},
 note = {Interaction between high power laser and various types of target has been investigated aiming at innovative application. The characteristics of plasma produced by such interaction, e.g. the structure and dynamics, the state and life time, are of specific importance. So far, the generation of high energy density plasma in a confined manner, such as magnetically confined plasma, has not been achieved ascribed to the strong pressure inhomogeneity, which easily leads to a destruction of the state. However, once such a plasma can be sustained in longer time scale in a confined manner, such as magnetically confined fusion (MCF) plasmas, one can extend the class of application to wider area significantly. Here, we propose a new concept, which we refer to as structured medium, consisting of plural different materials and/or mediums contacting with each other across boundary layer.

Clustered medium is one of examples. Recently, the conversing shock-induced blow-off acceleration (CSBA) in hydrogen cluster irradiated high intensity laser is successfully shown, which leads to the pure proton acceleration over 200 MeV/u. Here, we extended the scheme to more sophisticated structured target, which is a lattice-like rod assembly with sub-m size using technologies of beam lithography and chemical etching.

We have studied the interaction dynamics using such rod assembly using PIC simulations in two cases, (1) the case immersed in a high pressure ambient gas and (2) that in strong magnetic field around KT order. In case (1), we found that strong magnetic fields in KT order is generated by current filaments induced among rods, which confines high energy density plasma over inertia time, achieving beta (kinetic pressure/magnetic pressure) ~ 1. In case (2), we have successfully confined high energy density plasma as a miller plasma, one of the magnetic confinement scheme. The quasi-static radial electric field is found to play an important role in confining plasma, such as H-mode in MCF system.

The scheme sustaining high energy density plasma using structured medium with beta ~1 opens new paradigm for plasma physics, which can contribute understandings of complex dynamics and structure of MCF plasmas., The 6th Workshop on Magnetic Fields in Laboratory High Energy Density Plasmas（LaB2019）},
 title = {“Confinement” of high energy density plasma based on structured medium  -A new platform studying MCF plasmas using laser-},
 year = {2019}
}