Oxford Centre for High Energy Density Science (OxCHEDS)

Abstract:

We describe experiments that demonstrate the detrimental effect of a prepulse on the femtosecond-pulse-driven Xe IX laser. The mechanism of this effect is discussed in terms of the results of a hydrodynamic model of the preplasma formed by the prepulse. The benefit of inserting a simple electro-optic switch that allows full transmission of the main driving pulse, but reduces the prepulse to a level at which no preplasma is formed, is demonstrated experimentally. © 1997 Optical Society of America.

Abstract:

Hooker explores current work in the XUV and soft x-ray spectral region aimed at achieving "table-top" short-wavelength lasers.

Abstract:

Titania is the latest series of ultraviolet laser systems developed with the highest laser beam brightness. It can be configured in two alternative modes which can deliver a brightness of <1020 W cm-2 sterad-1. The first mode, used a chirped pulse amplification (CPA) to produce the shortest possible pulses. Values of 300 fs on the target are measured. The energy limitations of the CPA scheme are removed in the alternative architecture based on Raman beam combining. The Titania Raman system is designed to operate optimally with pulses of 30-500 ps duration.

Abstract:

A switch based on ultrashort pulse laser heating of diffraction crystals provide insights about x-ray diffraction that forms a synchrotron with sub-picosecond time resolution. A change is diffracted intensity results from thermal expansion of the crystal over an x-ray absorption depth. The reduction in diffracted intensity is limited by the laser fluence to about 15%. It also asserts that experiments using an ultrashort pulse Ti:Sapphire laser synchronized to the ring and a laser pump/x-ray probe are possible. With regards to temporal resolution, a higher level of it can be obtained by using an ultrafast streak camera synchronized to the laser.