Sensitivity and offset calibration for the beam position monitors at the Advanced Photon Source

Conference · Sat Jul 01 04:00:00 EDT 1995

OSTI ID:97280

Chung, Y; Barr, D; Decker, G; Evans, K Jr; Kahana, E

The beam position monitors (BPMs) play a critically important role in commissioning and operation of accelerators. Accurate determination of the offsets relative to the magnetic axis and sensitivities of individual BPMs is thus needed. We will describe in this paper the schemes for calibrating all of the 360 BPMs for sensitivity and offset in the 7-GeV Advanced Photon Source (APS) storage ring and the results. For the sensitivity calibration, a 2-dimensional map of the BPM response in the aluminum vacuum chamber is obtained theoretically, which is combined with the measured nonlinear response of the BPM electronics. A set of 2-dimensional polynomial coefficients is then obtained to approximate the result analytically. The offset calibration of the BPMs is done relative to the magnetic axis of the quadrupoles using the beam. This avoids the problem arising from various mechanical sources as well as the offset in the processing electronics. The measurement results for the resolution and long-term drift of the BPM electronics shows 0.06-{mu}m/{radical}Hz resolution and 2-{mu}m/hr drift over a period of 1.5 hrs.

• Research Organization: Argonne National Lab., IL (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 97280
• Report Number(s): ANL/ASD/CP--85066; CONF-950512--274; ON: DE95013732
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
ADVANCED PHOTON SOURCE
BEAM MONITORING
BEAM MONITORS
BEAM POSITION
CALIBRATION
SENSITIVITY