High heat load performance of an inclined crystal monochromator with liquid gallium cooling on the CHESS-ANL undulator
Abstract
Results for the performance of a novel double crystal monochromator subjected to high heat loads from an APS prototype undulator at the Cornell High Energy Synchrotron Source (CHESS) are presented. The monochromator was designed to achieve symmetric diffraction from asymmetric planes to spread out the beam footprint thereby lowering the incident power density. Both crystals had (111) oriented surfaces and were arranged such that the beam was diffracted from the (11 bar 1) planes at 5 KeV. Rocking curves with minimal distortion were obtained at a ring electron current of 96 mA. This corresponded to 370 Watts total power and an peak power density of 48 Watts/mm(exp 2) normal to the incident beam. These results are compared to data obtained from the same crystals in the standard geometry (diffracting planes parallel to surface). The footprint area in the inclined case was three times that of the standard case. We also obtained rocking curve data for the (333) reflection at 15 KeV for both standard and inclined cases, and these data also showed a minimal distortion for the inclined case. In addition, thermal data were obtained via infrared pyrometry. Not only the diffraction data but also the thermal data revealed a dramatically improved performance for the inclined crystal case.
- Publication:
-
Presented at the 7th National Conference and Exhibition on Synchrotron Radiation Instrumentation
- Pub Date:
- November 1991
- Bibcode:
- 1991sri..confQ..28M
- Keywords:
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- Crystals;
- Gallium;
- Liquid Cooling;
- Loads (Forces);
- Monochromators;
- Thermal Stresses;
- Bragg Angle;
- Diffraction;
- Synchrotron Radiation;
- Solid-State Physics