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A grazing incidence x-ray streak camera for ultrafast, single-shot measurements

Description: An ultrafast x-ray streak camera has been realized using a grazing incidence reflection photocathode. X-rays are incident on a gold photocathode at a grazing angle of 20 degree and photoemitted electrons are focused by a large aperture magnetic solenoid lens. The streak camera has high quantum efficiency, 600fs temporal resolution, and 6mm imaging length in the spectral direction. Its single shot capability eliminates temporal smearing due to sweep jitter, and allows recording of the ultrafast dynamics of samples that undergo non-reversible changes.
Date: February 18, 2010
Creator: Feng, Jun; Engelhorn, K.; Cho, B.I.; Lee, H.J.; Greaves, M.; Weber, C.P. et al.
Partner: UNT Libraries Government Documents Department

Correlation between nuclear response and defects in CZT

Description: Vertical high pressure Bridgman (VHPB) was considered until now to be the most successful crystal growth method to produce Cd{sub 1{minus}x}Zn{sub x}Te (CZT), (0.04 < x < 0.24), for X- and gamma-ray detector crystals. Recently Horizontal Bridgman (HB) Cd{sub 1{minus}x}Zn{sub x}Te crystals produced by IMARAD Co. have also been successfully fabricated into nuclear spectroscopic radiation detectors. In view of the database of many years' study of the electrical properties of VHPB CZT grown and obtained from various sources, the authors also studied the HB CZT crystals in order to compare the defects present in both different kinds of crystals grown by different methods. The VHB-grown samples were examined using thermoelectric emission spectroscopy (TEES), X- and gamma ray spectroscopy and laser induced transient charge technique (TCT). The surface and the bulk crystalline homogeneity were mapped using triaxial double crystal x-ray diffraction (TADXRD) and infrared transmission spectroscopy (IR). They have found a correlation between crystallinity, IR transmission microstructure and trapping times. Spectrometer grade VHPB CZT crystals exhibit trapping times of 20 {micro}s for electrons and 7 {micro}s for holes, however, regions, which were opaque to IR transmission, had trapping times shorter by one order of magnitude. The trapping times of HB CZT for electrons, were 10--15 {micro}s. A similar trend has been observed on VHPB CZT crystals with poor crystallinity. The HB CZT crystals that they measured in this study had a crystallinity that was inferior to that of the best spectroscopic grade VHPB crystals.
Date: July 19, 1999
Creator: Hermon, H.; Schieber, M.; James, R. B.; Lee, E.; Cross, E.; Goorsky, M. et al.
Partner: UNT Libraries Government Documents Department

Design, engineering and evaluation of refractory liners for slagging gasifiers. Final report

Description: The contract for this program was awarded at the end of September 1978. Work was started on 1 October 1978, on Tasks A, B, and E. Task A, Conceptual Liner Designs, and Task B, Test System Design and Construction, were completed. Task C, Liner Tests, and Task D, Liner Design Evaluation, were to begin upon completion of Task B. Task E, Liner Model Development, is inactive after an initial data compilation and theoretical model development effort. It was to be activated as soon as data were available from Task D. Task F, Liner Design Handbook, was active along with Task A since the reports of both tasks were to use the same format. At this time, Tasks C, D, and F are not to be completed since funding of this project was phased out by DOE directive. The refractory text facility, which was constructed, was tested and found to perform satisfactorily. It is described in detail, including a hazard analysis which was performed. (LTN)
Date: August 1, 1982
Creator: deTineo, B J; Booth, G; Firestone, R F; Greaves, M J; Hales, C; Lamoureux, J P et al.
Partner: UNT Libraries Government Documents Department