Oxford Centre for High Energy Density Science (OxCHEDS)

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.

Abstract:

We present measurements of the net-induced gain on the 5d-4f transition at 186 nm in LiYF4:Nd3+ optically pumped by radiation from a molecular fluorine laser. It is found that for LiYF4: Nd3+ one of a series of potential continuously tunable VUV lasers, relatively strong excited-state absorption results in net-induced loss. The prospects for VUV laser operation being realised in other rare-earth-doped fluorides is discussed.

Abstract:

The system of a synchrotron radiation utilizing X-ray streak camera for ultrafast experiments is discussed. The X-ray streak camera includes a short-pulse laser and an ultrafast subpicosecond X-ray detector that are accurately synchronized to the synchrotron. The camera's detector is considered to be the fastest, having a 0.54 ps single shot temporal resolution. The camera also has a pair of meander-type deflection plates found before a magnetic focusing lens which obtains very high sweep speeds on the exit phosphor. The duration of the X-ray beam from the synchrotron source was also measured to be at 5 kev.