Intense pulsed ion beams for fusion applications

Abstract

The subject of this review is the field of intense pulsed ion beam generation and its potential application to fusion research. Considerable progress has been made in the past six years. Power levels of the order of 1000 MW/cm2 have been obtained for pulse-lengths from 10−8 to 10−6 s. Light-ion beams with currents approaching 1 MA and energies exceeding 1 MeV have been produced. The first half of the paper treats the physics and technology of beam generation. Following a unified discussion of the theory of ion injectors, experimental work since 1973 is reviewed. Diagnostic techniques appropriate to high-flux ion beams are summarized. The general problem of high-current ion beam transport in vacuum and through plasmas is also considered. The second part of the paper is devoted to applications to fusion research. Applications in both magnetic confinement and inertial confinement fusion are considered. Intense ion beams have a number of features which make them ideally suited as inertial fusion drivers. Discussions are given of the physics of inertial fusion targets, options for ion beam production, experiments on light-ion beam focusing, and high-current multi-stage accelerators.

Measurement of Charged-Particle Stopping in Warm Dense Plasma

“…Understanding the transport of these α's in plasmas at extreme conditions is required to accurately model ignition experiments at the National Ignition Facility (NIF) [11], where significant α self-heating has recently been achieved [12]. Charged-particle transport in and heating of dense plasmas is also highly relevant to alternative particle-beam-driven inertial fusion designs such as heavyion fusion [13] and proton fast ignition [14,15].…”

Scaling Laws for Collisionless Laser–Plasma Interactions of Relevance to Laboratory Astrophysics

“…In order for this to be correct, the foil has to be thin enough so as to make energy losses of "oscillating" relativistic electrons negligible. One can also note in passing that a very similar setting has been studied in great detail in the problem of ion acceleration by electrons generated in a high-current diode and injected into vacuum (e.g., [14][15][16]; see also survey [17] of these early studies).…”

“…A variety of mechanisms for generation of a quasi-static magnetic field have been discussed in the past, including the thermo-electric dynamo [17] and a ponderomotive force [18]. These mechanisms easily explain the appearance of the toroidal magnetic field, as shown in Fig.…”

Atomic emission spectroscopy in high electric fields

“…The charge-exchange or@ of the Li neutrals impacts the electric field measurements because the Li neutral atoms acquire a high velocity transverse to the beam acceleration direction, due to the ion beam source divergence. This high transverse velocity results in large Doppler broadening (typically [10][11][12][13][14][15] %I > that prevents resolution of the individual Starweeman line components. In addition, measurements on the cathode side of the gap are not possible until neutrals arrive there, typically -10-15 nsec into the pulse.…”