Oxford Centre for High Energy Density Science (OxCHEDS)

Abstract:

This paper presents an improved analytical expression for the x-ray dynamic structure factor from a dense plasma which includes the effects of weakly bound electrons. This result can be applied to describe scattering from low to moderate Z plasmas, and it covers the entire range of plasma conditions that can be found in inertial confinement fusion experiments, from ideal to degenerate up to moderately coupled systems. The theory is used to interpret x-ray scattering experiments from solid density carbon plasmas and to extract accurate measurements of electron temperature, electron density, and charge state. The experimental results are applied to validate various equation-of-state models for carbon plasmas. (C) 2004 American Institute of Physics.

Abstract:

The observations of proton emission from wire targets, performed at the Rutherford Appleton Laboratory were reported. The experiments were carried out by using the Chirped Pulsed Amplification beam line of VULCAN laser facility. It was observed that the presence of objects in the vicinity of the interaction had an effect on the angular emission pattern of protons from the primary targets. The results show that the objects in close proximity of the main target can become sheath formation on the secondary object.

Abstract:

The use of ultrahigh intensity laser pulses (I>5×1019 W cm-2) to irradiate thin wire targets was analyzed. The current was produced by the escape of fast electrons from the target, which resulted in the well-localised optical emission from the additional wire . The MHD instabilities in the pinching plasmas along with field emission of electrons from nearby objects were also observed. The X-ray power levels can be enchanced from laser driven Z pinches using wire array and X-pinch configurations, the coherent optical transition radiation from adjacent objects was also observed.