Progress of the APS high heat load x-ray beam position monitor development

Several novel design developments have been established for the Advanced Photon Source (APS) insertion device (ID) X-ray beam position monitor (XBPM) to improve its performance: (1) optimized geometric configuration of the monitor`s sensory blades; (2) smart XBPM system with an intelligent digital signal processor, which provides a self-learning and calibration function; and (3) transmitting XBPM with prefiltering in the commissioning windows for the front end. In this write-up, the authors summarize the recent progress on the XBPM development for the APS ID front ends

Cryogenic cooling of x-ray crystals using porous matrix

It is well established that Si and SiC have very desirable thermophysical properties at cryogenic temperatures. This feature makes cryo-cooled optics potentially a good candidate for the first optical crystal of the presently built third generation synchrotron machines with very high heat flux levels. Currently, there is a great deal of interest in such cryo-cooled crystals pursued both experimentally and analytically. The analytical studies involve cut micro or capillary channel crystals. As opposed to the machined channels, porous matrices provide significant advantages. They operate very quietly. Such matrices are known to affect superior heat transfer enhancement. Data available in open literature suggest that surface heat flux levels up to {approximately}8 kW/cm{sup 2} are possible. For cryogens for which the boiling heat transfer heat flux is rather a low value in conventional geometries, the enhancement available with such matrices is a very significant characteristic. Cryogens are poor thermal conductors themselves. The fact that at the cryogenic temperatures the Si and/or SiC matrix itself becomes highly conductive, the matrix distributes the surface heat flux into the full volume effectively offsetting the poor conductivity of the coolant. In addition the tortuous path of the coolant through the matrix increases the dwell time for better heat transfer, however, at the expense of increased pressure drop. In this study, thermal conductivity of such composite matrices and the effective heat transfer coefficient obtainable using them are investigated. A first optics crystal model of Si with Si and/or Sic porous matrix as its heat exchanger and subject to prototype synchrotron level heat flux is analyzed and limits of the cooling possible with liquid nitrogen in single phase and subcooled boiling heat transfer modes are delineated

Overview of thermal-buoyancy-induced phenomena in reactor-plant components. [LMFBR]

Studies related to delineating the influence of thermal-buoyancy forces on the thermal-hydraulics of Liquid Metal Fast Breeder Reactor plant components under low-flow thermal transient and steady state conditions have generated unique information which will aid design of these components. Various buoyancy force induced phenomena such as thermal stratification, flow recirculation, stagnation, and channeling are described and the importance to component performance are discussed. The water based studies have been conducted in the Mixing Components Test Facility, a large multi program facility capable of performing generic studies of fluid flow and heat transfer in reactor components under programmed transient and steady state conditions

Synthetic diamond-based position-sensitive photoconductive detector development for the Advanced Photon Source

A novel x-ray beam position detection device that we call a position sensitive photoconductive detector (PSPCD) is designed to have synthetic diamond as its substrate material. We proved that it is feasible to use synthetic diamond to make a hard x-ray position sensitive detector based on the photoconductivity principle and that acts as a solid state ion chamber. Experiments on different PSPCD samples using synthetic diamond with high heat flux white undulatory beam, as well as with monochromatic hard x-ray beams, have been done at the Advanced Photon Source. Recent test results with the PSPCD in quadrant configuration as an x-ray beam position monitor and in a multipixel array as an x-ray beam profile are presented in this paper