Signal processing, data acquisition, and initial commissioning results of the APS storage ring vertical beam missteering wire monitor

Two wire monitors have been developed and installed in the Advanced Photon Source (APS) storage ring insertion device (ID) front ends to directly detect synchrotron radiation exiting the storage ring vacuum chamber that is missteered by ±5 mm. Each wire monitor employs four in-vacuum tungsten wires positioned above and below the normal x-ray orbit. The temperature change of the wire under x-ray irradiation causes a resistance change that is detected by a local high-sensitivity low-noise signal processing electronics unit with four independent channels. The four outputs of the local unit are linked to a central VME wire resistance measurement and interlock module via 4 endash 20 mA current loops. The central VME module can accept inputs from up to eight wire monitors and has a heartbeat that feeds a MPS summation module. In this paper, an overview of the wire monitor signal processing and data acquisition system design is presented together with recent commissioning results. copyright 1996 American Institute of Physics