Dissociative excitation of the HgI (B–X) band system and atomic mercury lines was observed during collisions of CO+ ions with CH3HgI molecules in the laboratory kinetic energy range 100–1000 eV. By the use of the integrated intensity of the most intense band of the (B–X) transition of the HgI radical at 445 nm, emission cross sections were measured at different kinetic energies of these ions.

A method of absolutely unfolding the atomic spectrum by a pinhole transmission grating spectrometer (TGS) is discussed in detail. The numerical process considers both the factors of higher-dispersive-order overlapping of TGS and source-size widening effects. Real soft-X-ray spectra of aluminum, copper, and gold plasmas are presented of experiments performed on the Six-Beam Laser Facility at the Shanghai Institute of Optics and Fine Mechanics.

The possibility of compressing the cryogenic hollow pellet of inertial confinement nuclear fusion with multiple adiabatic shock waves is discussed, on the basis of the estimation of the properties of a high-density deuterium plasma (1024−1027 cm−3, 10−1−104 eV), such as the velocity and the attenuation constant of the adiabatic sound wave, the width of the shock wave, and the surface tension.

It is found that in the course of compression the wavelength of the adiabatic sound wave and the width of the weak shock wave sometimes become comparable to or exceed the fuel shell width of the pellet, and that the surface tension is negative. These results show that it is rather difficult to compress stably the hollow pellet with successive weak shock waves.

To investigate the influence of radiation reabsorption on the level populations of ions in an expanding laser-produced plasma of intermediate density, we start with the system of rate equations for the population densities coupled with the line-radiation transport equation, the dynamical Doppler effect due to the differential macroscopic velocity field included. In a physically motivated approximation, for spatially varying absorption and emission, and general three-dimensional plasma geometry, an integral equation describing the effect of Lyman-a radiation reabsorption on the spatial behavior of the population density of the upper resonance level is derived. Assuming a sufficiently large velocity gradient so that the Doppler-induced frequency shift dominates the linewidth, after asymptotically evaluating the frequency integral involved in the kernel we are led to a simplified integral equation exhibiting the reduction of radiation reabsorption by Doppler decoupling. In particular, in the case of a cylindrical, radially expanding laser plasma we discuss this Fredholm equation for the reabsorption-influenced population density.

A computer model has been developed and benchmarked for the nuclear-pumped atomic carbon laser. Experiments have been performed with the atomic carbon laser and with the radiolysis of CO2 as a benchmark for the model. The results of the CO2 radiolysis are described.

Large (megagauss) “spontaneous” magnetic fields are produced by laser–plasma interactions when a short, powerful laser pulse is focused to a small diameter onto a solid target. The relevance of these magnetic fields to inertial confinement fusion applications depends on the numerous ways in which they can affect laser–plasma interactions and the resulting plasma. Theoretical studies have dealt with a variety (thermal, radiative, and dynamo) of generation mechanisms and with the associated transport and instability phenomena. The fields, originally observed with small induction probes placed near the target, have been studied in the focal region by optical methods. These optical diagnostics have used Faraday rotation of a probing laser beam and Zeeman profiles of emitted spectral lines.

For first investigations of hot dense matter produced by intense heavy-ion beams we built an electrostatic quadrupole doublet that focused Ar+and Kr+ ions of 45 keV/amu after acceleration through the radio frequency quadrupole (RFQ) accelerator at the GSI onto a small spot of approximate area 1 mm2. This beam then deposited a specific beam power of about 1.5 GW/g to targets.

The temperatures and the densities of plasmas produced by high-power lasers vary widely but in certain cases are similar to those found in astrophysical plasmas. In recent years our understanding of intense laser–matter interaction and the evolution of the resulting

plasma has increased to the point where experiments can be designed to produce plasmas that allow astrophysical models to be tested. In this paper I review experimental work on laser-produced plasmas that is relevant to astrophysics. In the fields of highlyionized ion line identification and radiative opacity, relevant measurements have already been performed. Other experiments that could be performed with current laser facilities, including studies of X-ray nebula plasmas and complex radiation line transport, are described. In addition, experiments to investigate plasmas under more extreme conditions, which may be achievable with more powerful lasers, are mentioned.