非磁化プラズマ中での強い電子ビームの伝搬およびビーム変調と放射マイクロ波との相関

取得学位：博士(理学)，学位授与番号：博甲第514号，学位授与年月日：平成14年3月22日,学位授与年：200

Study of the spatial distribution of the Langmuir wave amplitude in the turbulent plasma using electron beam shadowgraph technique

New diagnostic, "electron-beam-shadowgraph", is examined for taking the spatial distribution of transient fields in a plasma. It is applied to the unmagnetized plasma, which is perturbed by an intense relativistic electron beam (IREB). Strong deflection is observed with duration of about 1 μs just after the IREB injection. The shadowgraph image is characterized by presence of aggregate holes. The size of the hole is changed with the plasma density, and corresponds to the 15 - 60 Debye lengths. Important agreements are observed between the experiment and the strong Langmuir turbulence theory. © 2002 AIP