Development of a grazing-incidence insertion device X-ray beam position monitor at the Advanced Photon Source

Abstract

Beam stability is always a concern in synchrotron light source facilities, and accurate and stable X-ray beam position monitors (XBPM) are key elements in obtaining desired user beam stability. Currently, Advanced Photon Source is preparing to upgrade its facility to increase productivity and to provide better beam stability. For better beam stability, a grazing-incidence insertion device X-ray beam position monitor (GRID-XBPM) is proposed for the insertion device beamline front ends instead of the current photoemission-based XBPM. The design and development of the GRID-XBPM are summarized in this paper including the thermal simulation results of the GRID-XBPM. Thermal and stress analyses show that it withstands the 21 kW total beam power and the peak heat flux of 1684 W mm−2 at a grazing incidence angle of 0.80° using a heat transfer coefficient of 0.010 Wmm−2 °C−1.