Dm. Shu et al., SMART X-RAY-BEAM POSITION MONITOR SYSTEM USING ARTIFICIAL-INTELLIGENCE METHODS FOR THE ADVANCED PHOTON SOURCE INSERTION-DEVICE BEAMLINES, Journal of synchrotron radiation, 5, 1998, pp. 632-635
At the Advanced Photon Source (APS), each insertion-device (ID) beamli
ne front end has two X-ray beam position monitors (XBPMs) to monitor t
he X-ray beam position for both vertical and horizontal directions. Pe
rformance challenges for a conventional photoemission-type XBPM during
operations are contamination of the signal from the neighbouring bend
ing-magnet sources and the sensitivity of the XBPM to the insertion-de
vice gap variations Problems are exacerbated because users change the
ID gap during their operations, and hence the percentage level of the
contamination in the front-end XBPM signals varies. A smart XBPM syste
m with a high-speed digital signal processor has been built at the Adv
anced Photon Source for the LD beamline front ends. The new version of
the software, which uses an artificial-intelligence method, provides
a self-learning and self-calibration capability to the smart XBPM syst
em. The structure of and recent test results with the system are prese
nted in this paper.