Self-organized and chaotic motions emerging in nonlinear development of instabilities in plasmas are reviewed. With a special focus on ion beam-plasma instability, an underdense plasma instability associated with stimulated Raman scatterring, collisional drift wave instability and Diocotron instability, notions of nonlinear entities such as solitons, vortices, and chaos are shown to be crucial to an understanding of the underlying physics at a saturated stage of instabilities.

抄録全体を表示

An electron collision cross section data base for low temperature plasmas is strongly, needed in various fields of plasma technologies such as gas insulation, discharge lamp, plasma processing for etching and deposition, pollution control using plasma and others. This article reports the current state of electron and ion collision physics, and describes a self-consistent set of gases needed for modeling plasma devices based on the technical report “Electron Collision Cross Section Data Base for Low Temperature Plasma” published by The Institute of Electrical Engineering of Japan.

抄録全体を表示

The progress in development of high-power glass laser systems during the past 30 years is remarkable NIF (National Ignition Facility), which will deliver 1.8 MJ at 0.35 μm is now construction in the United States. Recently, technology that smoothes out the focal pattern has been developed to a great extent. RPP (Random Phase Plate) and PCL (Partially Coherent Laser) both gave an excellent focal pattern with standard deviation of 3% in the Gekko XII laser system. In the US, Japan and Europe, several ultra-short pulse lasers were developed for research on “fast ignition”. “Fast ignition” is a method which will reduce the total required laser energy for ignition. Because a diode-pumped, solid state laser can operate at a repetition rate of over 10 Hz with an efficiency of about 10% research area of high-power systems at the 1 kW level started to focus on the development of a driver for a commercial laser fusion reactor.

抄録全体を表示

A brief review is given of the requirements of inertial fusion energy drivers and their status and prospects in the U.S. Drivers based on lasers (diode-pumped solid-state and KrF) and heavy ions are discussed.

抄録全体を表示

Inertial fusion with heavy ion beams is promising for future energy production. We report the present status of technology based on two concepts of heavy ion beam drivers. One consists of RF linacs and storage rings and another is based on induction linacs. Both concepts encounter technical problems regarding the acceleration and manipulation of intense beams.

抄録全体を表示

Inertial confinement nuclear fusion driven by X-ray from Z-pinch plasmas has been developed. Recently, extremely high X-ray power (290 TW) and energy (1.8 MJ) were produced in fast Z-pinch implosions on the Z accelerator (Sandia National Laboratories). Wire arrays are used to produce the initial plasma. The X-ray from Z-pinch plasmas produced by pulsed power has great potential as a driver of inertial confinement nuclear fusion.

抄録全体を表示

A new gyrokinetic particle simulation method using the orbit averaged electron drift-kinetic equation has been developed in a three dimensional slab geometry. Using the large discrepancy between the time scale of the low frequency fluctuations and the Courant-Friedlichs-Lewy condition determined by the electron ballistic mode, the transit time ordering, ω/ω_trθ(ε), is introduced. The motion of the high energy transit electron is averaged over the periodic unperturbed orbit by means of the action-variational Lie perturbation method. In a new gyrokinetic Vlasov-Maxwell system, the drift-kinetic equation for the high energy part of the electron distribution function reduces to a two dimensional problem, which involves only the E×B nonlinearity, and the adiabatic response to the low frequency fluctuation is renormalized in the field equation. The ballistic mode arising from the high energy transit electron is removed and a longer simulation time step is enabled.

抄録全体を表示

The locality and spatial controllability of ECCD are numerically analyzed by changing the direction and location of EC beam injection. The optimum angles of beam injection are obtained for the most localized current drive and the maximum drive efficiency. The profile of the driven current with the maximum efficiency is very broad, i.e., not suitable for localized current drive. When the location of driven current is controlled by the beam injection from the equatorial plane, the locality is extremely destroyed due to the refraction of the ray according to the location of cyclotron resonance layer. The locality is well kept by the injection from an upper or lower side of the equatorial plane.

抄録全体を表示