摘要:

Microwave‐driven experiments and particle simulation calculations are presented that models‐polarized laser light incident on a pellet. In the microwave experiments, the incident microwaves are observed to decay into ion and electron waves near the critical density if the microwave power is above a well‐defined threshold. Significant absorption, thermal electron heating, and hot electron generation are observed for microwave powers above a few times threshold. Strong absorption, strong profile modification, strongly heated hot electrons with a Maxwellian distribution, a hot‐electron temperature that increases slowly with power, and a hot‐electron density that is almost constant, are all observed in both the microwave experiments and simulation calculations for high powers. In addition, the thermal electrons are strongly heated for high powers in the microwave experiments.

ISSN:0031-9171    

DOI:10.1063/1.865447

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

An analytic model is developed to describe the final state reached by a gas‐filled spherical shell compressed by a constant ablation pressure. The model takes into account the solid compressibility and the mass loss by ablation, and gives the magnitudes that characterize the state of the gas and solid when the implosion stagnates. The model provides an adequate physics interpretation and an extension of a recently reported model [B. Ahlborn, M. H. Key, and A. R. Bell, Phys. Fluids25, 541 (1982)]. The restrictions of the model imposed by the approximations adopted are discussed. The results are compared with available numerical simulation data and with the previous model already mentioned, and the main differences between them are discussed.

ISSN:0031-9171    

DOI:10.1063/1.865448

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Stimulated Raman scattering (SRS) was studied in experiments with laser‐irradiated Au disk targets. Typically the laser energy was 150 J in a 1.0 nsec pulse at a wavelength of 526 nm. Laser intensity at the target was ∼7×1014W/cm2. The spectrum, angular distribution, onset time, duration, and intensity of the Raman light were measured. In addition the electron density distribution was determined by holographic interferometry and images of the Raman emission were obtained. These data show that the Raman light is primarily backscattered and that scattering occurs at electron plasma densities 0.01nc≤n≤0.15nc. SRS occurred at laser intensities which are below theoretical thresholds, given the plasma conditions. Otherwise, most of the data support the present understanding of Raman scattering.

ISSN:0031-9171    

DOI:10.1063/1.865449

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

A simple saturation condition for a magnetic turbulence is derived based on the nonlinearity of electron orbit diffusion, which is applied for derivation of transport coefficients in the reversed field pinch plasmas. The scalings as well as magnitudes of the plasma temperature and energy confinement time in the collisionless limit agree fairly well with those of reversed field pinch experiments.

ISSN:0031-9171    

DOI:10.1063/1.865450

出版商:AIP    

年代:1986

数据来源: AIP

ISSN:0031-9171    

DOI:10.1063/1.866027

出版商:AIP    

年代:1986

数据来源: AIP