Oxford Centre for High Energy Density Science (OxCHEDS)

Abstract:

We report an investigation of a high-pressure molecular fluorine laser operating at 158 nm. Several cavity configurations were studied, including one employing a roof prism as the high reflector. A maximum VUV pulse energy of 237 mJ, corresponding to a specific output of 3.3 J/1 was obtained when the laser was operated as a double-ended device. With single-ended operation the largest output energy was 176 mJ at a specific output of 2.5 J/1. © 1992 Springer-Verlag.

Abstract:

The time dependence of the angular distribution of soft X-ray lasing at 23.6 nm in Ne-like germanium has been measured using a streak camera. Slabs of germanium have been irradiated over ≈ 22 mm length × 100 μm width with three line focussed beams of the SERC Rutherford Appleton Laboratory VULCAN laser at 1.06 μm wavelength. The laser beam sweeps in time towards the target surface plane and the divergence broadens with time. The change of the peak intensity pointing and the broadening of the profile with time are consistent with expectations of the time dependence of refraction and divergence due to density gradients in the plasma. © 1992.

Abstract:

A high brightness KrF Raman laser generating 60 GW, 40 ps pre-pulse free pulses has been focused to an 8 μm focal spot at 9x1016W cm-2. Axial and lateral transport of energy has been studied by analysis of X-ray images of the focal spot and from X-ray spectra emitted by a thin layer of aluminium beneath a variable thickness of CH polymer on planar targets. The results show strong lateral transport of energy and reduced axial penetration of heating. © 1992.