Ultra Fast X-Ray Detector

The Department of Energy seeks to advance its user facilities for ultrafast x-ray science, which deals with physical phenomena that occur in the range of one-trillionth of a second (one picosecond) to less than one-quadrillionth of a second (one femtosecond). Ultrashort lasers are used to produce these ultrashort x-ray pulses. However, there is a great need for characterization and control technologies that are capable of measuring and controlling the intensity, as well as the temporal and spectral characteristics, of these ultra-short x-ray pulses. In particular, available x-ray detectors do not have the required time response. This project will develop a GaAs x-ray detector with sub ps rise time and timing precision. Neutron pre-treatment will be used to reduce carrier lifetime, and a co-planar microstrip line will be used to achieve an ultrahigh frequency response. Commercial Applications and other Benefits as described by the awardee: The GaAs photoconductive detectors (PCDs) should find applicability to the characterization of a broad range of pulsed radiation sources. The ability to characterize and control ultrashort x-ray pulses should such impact diverse scientific disciplines as atomic and molecular physics, chemistry and chemical biology, and materials science. The detectors also should be expected to make a direct contribution to the characterization of inertial confinement fusion sources.