BIW2012 - List of Authors (Ramanathan, M.)

Paper	Title	Page
WECP01	High-Power Beam Test of the APS Grazing-Incidence Insertion Device X-ray Beam Position Monitor	235
	B.X. Yang, J.T. Collins, G. Decker, P.K. Den Hartog, T.L. Kruy, N.G. Kujala, S.-H. Lee, M. Ramanathan ANL, Argonne, USA
	Funding: Work supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. A grazing-incidence insertion device x-ray beam position monitor (GRID-XBPM) has been under design and construction at the APS for the past two years. At an 0.85 degree grazing incidence angle, the XBPM assembly was designed to withstand two inline Undulator A devices operating at 150 mA beam current, a total power of 16 kW. We report the first x-ray beam test of the XBPM in 29ID-A, the first optical enclosure, at up to 50% of its design capacity. Thermal imaging measurements were performed for the absorber and found a maximum of ~ 15°C temperature rise on the outside surfaces of the copper chamber walls. In the direction perpendicular to the beamline aperture, the center-of-mass detectors appear to provide good beam position signals for the total undulator beam power from 17 W to 10.6 kW, covering nearly three decades. The gap-dependent offset for the XBPM is also dramatically reduced. In the direction parallel to the beamline aperture, the center-of-mass measurement is impossible and the XBPMs gain (calibration) is gap dependent. However, the reduced gap-dependent offsets will allow the XBPM to work reliably near the origin.

Paper

Title

Page

High-Power Beam Test of the APS Grazing-Incidence Insertion Device X-ray Beam Position Monitor

235

B.X. Yang, J.T. Collins, G. Decker, P.K. Den Hartog, T.L. Kruy, N.G. Kujala, S.-H. Lee, M. Ramanathan
ANL, Argonne, USA

Funding: Work supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
A grazing-incidence insertion device x-ray beam position monitor (GRID-XBPM) has been under design and construction at the APS for the past two years. At an 0.85 degree grazing incidence angle, the XBPM assembly was designed to withstand two inline Undulator A devices operating at 150 mA beam current, a total power of 16 kW. We report the first x-ray beam test of the XBPM in 29ID-A, the first optical enclosure, at up to 50% of its design capacity. Thermal imaging measurements were performed for the absorber and found a maximum of ~ 15°C temperature rise on the outside surfaces of the copper chamber walls. In the direction perpendicular to the beamline aperture, the center-of-mass detectors appear to provide good beam position signals for the total undulator beam power from 17 W to 10.6 kW, covering nearly three decades. The gap-dependent offset for the XBPM is also dramatically reduced. In the direction parallel to the beamline aperture, the center-of-mass measurement is impossible and the XBPMs gain (calibration) is gap dependent. However, the reduced gap-dependent offsets will allow the XBPM to work reliably near the origin.