Commissioning the beam diagnostics for the PEP-II B Factory
Abstract
PEP-II is a 2.2-km-circumference collider with a 2.1-A, 3.1-GeV positron ring (the Low-Energy Ring) 1 m above a 1-A, 9-GeV electron ring (the High-Energy Ring); both rings are designed for a maximum current of 3 A. The authors describe the beam diagnostics and present measurements from HER commissioning. The beam profile is measured using near-UV synchrotron light extracted by grazing-incidence mirrors that must withstand up to 200 W/cm. Normally 1,658 of the 3,492 buckets will be filled, and the charge must be equal within 2%. To measure the charge in each bucket, the sum signal from a set of 4 pickup buttons is digitized and averaged over 256 samples per bucket in every 60-Hz interval. The sum is them normalized to the ring current, measured by a DC current transformer. The 300 beam-position monitors per ring are multiplexed to share 171 processor modules, which use DPSs for recording positions over 1,024 turns and for calibration. For both diagnostics and machine protection, 100 photomultipliers with fused-silica Cherenkov radiators measure beam losses and can trigger a beam abort in case of high loss. For the ring tunes, signals from a set of 4 pickup buttons are combined into horizontal, vertical, and summore »
- Authors:
-
- and others
- Publication Date:
- Research Org.:
- Stanford Univ., Stanford Linear Accelerator Center, CA (US)
- Sponsoring Org.:
- USDOE Office of Energy Research, Washington, DC (US)
- OSTI Identifier:
- 666111
- Report Number(s):
- SLAC-PUB-7837; CONF-981040-
ON: DE98059231; TRN: US200305%%1135
- DOE Contract Number:
- AC03-76SF00515
- Resource Type:
- Conference
- Resource Relation:
- Conference: 3. European workshop on beam diagnostics and instrumentation for particle accelerators (DIPAC 97), Frascati (IT), 10/12/1998--10/14/1998; Other Information: Supercedes report DE98059231; PBD: Jun 1998; PBD: 1 Jun 1998
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 43 PARTICLE ACCELERATORS; ACCELERATORS; BEAM POSITION; BEAM PROFILES; CALIBRATION; COMMISSIONING; CONTROL ROOMS; ELECTRON RINGS; MIRRORS; MONITORS; PHOTOMULTIPLIERS; POSITRONS; RADIATORS; RING CURRENTS; SYNCHROTRONS
Citation Formats
Fisher, A S, Alzofon, D, and Collins, B. Commissioning the beam diagnostics for the PEP-II B Factory. United States: N. p., 1998.
Web.
Fisher, A S, Alzofon, D, & Collins, B. Commissioning the beam diagnostics for the PEP-II B Factory. United States.
Fisher, A S, Alzofon, D, and Collins, B. 1998.
"Commissioning the beam diagnostics for the PEP-II B Factory". United States. https://www.osti.gov/servlets/purl/666111.
@article{osti_666111,
title = {Commissioning the beam diagnostics for the PEP-II B Factory},
author = {Fisher, A S and Alzofon, D and Collins, B},
abstractNote = {PEP-II is a 2.2-km-circumference collider with a 2.1-A, 3.1-GeV positron ring (the Low-Energy Ring) 1 m above a 1-A, 9-GeV electron ring (the High-Energy Ring); both rings are designed for a maximum current of 3 A. The authors describe the beam diagnostics and present measurements from HER commissioning. The beam profile is measured using near-UV synchrotron light extracted by grazing-incidence mirrors that must withstand up to 200 W/cm. Normally 1,658 of the 3,492 buckets will be filled, and the charge must be equal within 2%. To measure the charge in each bucket, the sum signal from a set of 4 pickup buttons is digitized and averaged over 256 samples per bucket in every 60-Hz interval. The sum is them normalized to the ring current, measured by a DC current transformer. The 300 beam-position monitors per ring are multiplexed to share 171 processor modules, which use DPSs for recording positions over 1,024 turns and for calibration. For both diagnostics and machine protection, 100 photomultipliers with fused-silica Cherenkov radiators measure beam losses and can trigger a beam abort in case of high loss. For the ring tunes, signals from a set of 4 pickup buttons are combined into horizontal, vertical, and sum signals. Two signals are selected and downconverted into the range of a 10-MHz, 2-channel, programmable, DSP-based spectrum analyzer, connected over ethernet to the control room.},
doi = {},
url = {https://www.osti.gov/biblio/666111},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Jun 01 00:00:00 EDT 1998},
month = {Mon Jun 01 00:00:00 EDT 1998}
}