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High heat load crystal cooling strategies for an APS wiggler beamline

Description: High energy wigglers produce extremely high total powers. For example, the insertion device for one beamline of the Basic Energy Sciences Synchrotron Research Center (BESSRC) is an elliptical multipole wiggler (EMPW) which can generate circularly polarized X-rays on axis and produces a total power of {approximately}8 kW. This insertion device will be used to simultaneously provide x-rays to three branch lines, a branch equipped with a normal double crystal monochromator feeding a scattering and spectroscopy station, and two branches with single-bounce horizontally deflecting monochromators for Compton scattering and High Energy Diffraction. The crystal optics for this type of device require substantially different heat load solutions than those used for undulator beamlines. We will discuss how the beam is split and shared among the beamline branch lines and present the crystal cooling strategies employed for both the double-crystal monochromator and horizontally deflecting single-bounce monochromators.
Date: July 1, 1997
Creator: Beno, M.A.; Knapp, G.S. & Engbretson, M.
Partner: UNT Libraries Government Documents Department

Synchrotron and laboratory studies utilizing a new powder diffraction technique

Description: We have developed a new type of powder diffractometer that is much more efficient than existing methods. The diffractometer has the potential of both high count rates and very high resolution when used at a synchrotron source. The laboratory based instrument has an order of magnitude improvement in count rate over existing methods. The method uses a focusing diffracted beam monochromator in combination with a multichannel detector. The incident x-rays fall on a flat plate or capillary sample and are intercepted by a bent focusing monochromator which has the focus of the bend at the sample surface. The powder diffraction lines emerging from the bent crystal monochromator are detected by a linear or 2-dimensional detector. This allows us to eliminate the background from fluorescence or other scattering and to take data over a range of 3{degrees} to 4{degrees} instead of one angle at a time thereby providing a large improvement over conventional diffractometers. Results are presented for fluorapatite Fe{sub 2}O{sub 3}, and a high-TC superconductor.
Date: October 1, 1992
Creator: Knapp, G. S.; Beno, M. A.; Jennings, G.; Engbretson, M. & Ramanathan, M.
Partner: UNT Libraries Government Documents Department

Synchrotron and laboratory studies utilizing a new powder diffraction technique

Description: We have developed a new type of powder diffractometer that is much more efficient than existing methods. The diffractometer has the potential of both high count rates and very high resolution when used at a synchrotron source. The laboratory based instrument has an order of magnitude improvement in count rate over existing methods. The method uses a focusing diffracted beam monochromator in combination with a multichannel detector. The incident x-rays fall on a flat plate or capillary sample and are intercepted by a bent focusing monochromator which has the focus of the bend at the sample surface. The powder diffraction lines emerging from the bent crystal monochromator are detected by a linear or 2-dimensional detector. This allows us to eliminate the background from fluorescence or other scattering and to take data over a range of 3[degrees] to 4[degrees] instead of one angle at a time thereby providing a large improvement over conventional diffractometers. Results are presented for fluorapatite Fe[sub 2]O[sub 3], and a high-TC superconductor.
Date: October 1, 1992
Creator: Knapp, G.S.; Beno, M.A.; Jennings, G.; Engbretson, M. & Ramanathan, M.
Partner: UNT Libraries Government Documents Department