ANL, Argonne
YerPhI, Yerevan
A 5-wire vibrating wire monitor (VWM005) was developed and tested at the Advanced Photon Source (APS). The sensor was mounted on the outboard side of a bending-magnet synchrotron radiation terminating flange in sector 37 of the APS storage ring. The parallel wires were separated vertically by 0.5 mm; however, due to the possibility of rotation about a horizontal axis, the effective distance between the wires was reduced by 30%. To increase the response speed, the sensor was installed in air, resulting in a step response time of less than one second. Due to the extreme sensitivity of the detector, the very hard x-ray component of synchrotron radiation was successfully measured after its passage through the terminating flange.
ANL, Argonne
The Advanced Photon Source (APS) monopulse beam position monitor (BPM) system, designed to measure single- and multi-turn beam positions, is one of three BPM systems currently in use to measure and control both AC and DC orbit motions. Recently, one sector of the monopulse BPM system was upgraded by replacing its ca 1992 12-bit signal conditioning and digitizing unit (SCDU) with a field-programmable gate array (FPGA)-based system for signal processing. The system is comprised of a repackaging of the broadband rf receiver modules together with a VME Extensions for Instrumentation (VXI) module housing eight 14-bit digitizers and one FGPA. The system will be described in detail, including an overview of its new functionality, and performance will be discussed. Of particular interest is the noise floor, which will be contrasted with the previous system and with other systems in use at the APS.
ANL, Argonne
There are two parallel feedback systems to correct the transverse orbit at the Advanced Photon Source (APS) storage ring: a real-time feedback system that runs at 1.5 kHz using 38 fast correctors and up to 160 beam position monitors (BPMs), and a DC feedback system that runs at 10 Hz using up to 317 correctors and over 500 BPMs. An algorithm that uses the open- and closed-loop beam motion data to spatially locate strong noise sources in the storage ring is described. A simulation code has been developed to predict the ideal closed-loop beam motion data from measured open-loop beam motion data assuming no steering corrector noise. With the difference between predicted and measured closed-loop beam motion data and the full inverse response matrix, we compute the source candidate locations and infer their relative strengths for narrowband sources. The simulation process and experimental results with beam will be presented.