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Title: Report on Operation of Antiproton Decelerator

Abstract

The Antiproton Decelerator (AD) at CERN operates for physics since 1999. The 3.5 GeV/c antiprotons produced in the target by a 26 GeV/c proton beam coming from CERN PS. Since the experiments need a low energy antiprotons, beam is decelerated in the AD down to an extraction momentum of 100 MeV/c. Due to significant emittance blow up during deceleration, as well as tight requirements from experiments on extracted beam sizes, efficient compression of beam phase space is indispensable. Two cooling systems, stochastic and electron are used in AD. The progress in machine performance is reviewed, along with plans for the future. Special emphasis is given to the proposed new extra low energy antiproton ring (ELENA) for deceleration of antiproton beam further down to an energy of 100 keV (momentum 13.7 MeV/c), which would allow much higher antiproton capture rate with significantly higher beam density.

Authors:
 [1]
  1. AB Department CERN CH-1211 Geneva 23 (Switzerland)
Publication Date:
OSTI Identifier:
20798445
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 821; Journal Issue: 1; Conference: COOL05: International workshop on beam cooling and related topics, Galena, IL (United States), 18-23 Sep 2005; Other Information: DOI: 10.1063/1.2190092; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; ACCELERATION; ANTIPROTON BEAMS; ANTIPROTON SOURCES; ANTIPROTONS; BEAM COOLING; BEAM DYNAMICS; BEAM EXTRACTION; BEAM OPTICS; CERN; COOLING SYSTEMS; ELECTRONS; GEV RANGE; KEV RANGE; MEV RANGE; PERFORMANCE; PHASE SPACE; PROTON BEAMS; SYNCHROTRONS

Citation Formats

Belochitskii, Pavel. Report on Operation of Antiproton Decelerator. United States: N. p., 2006. Web. doi:10.1063/1.2190092.
Belochitskii, Pavel. Report on Operation of Antiproton Decelerator. United States. doi:10.1063/1.2190092.
Belochitskii, Pavel. Mon . "Report on Operation of Antiproton Decelerator". United States. doi:10.1063/1.2190092.
@article{osti_20798445,
title = {Report on Operation of Antiproton Decelerator},
author = {Belochitskii, Pavel},
abstractNote = {The Antiproton Decelerator (AD) at CERN operates for physics since 1999. The 3.5 GeV/c antiprotons produced in the target by a 26 GeV/c proton beam coming from CERN PS. Since the experiments need a low energy antiprotons, beam is decelerated in the AD down to an extraction momentum of 100 MeV/c. Due to significant emittance blow up during deceleration, as well as tight requirements from experiments on extracted beam sizes, efficient compression of beam phase space is indispensable. Two cooling systems, stochastic and electron are used in AD. The progress in machine performance is reviewed, along with plans for the future. Special emphasis is given to the proposed new extra low energy antiproton ring (ELENA) for deceleration of antiproton beam further down to an energy of 100 keV (momentum 13.7 MeV/c), which would allow much higher antiproton capture rate with significantly higher beam density.},
doi = {10.1063/1.2190092},
journal = {AIP Conference Proceedings},
number = 1,
volume = 821,
place = {United States},
year = {Mon Mar 20 00:00:00 EST 2006},
month = {Mon Mar 20 00:00:00 EST 2006}
}
  • During the first 5 years of running for physics, the CERN Antiproton Decelerator (AD) has delivered antiprotons at 100 MeV/c to the ATRAP, ATHENA and ASACUSA collaborations and at 300 MeV/c to the ACE experiment. A rundown of the improvements in cycle duration, beam intensity and density over this period will be given. Limiting factors for improved performance will be discussed as well as planned and possible future improvements. Details and layout of a proposed new ring for further deceleration, ELENA, with the purpose of increasing beam density and trapping efficiency at the experiments are presented.
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  • The motion of polar molecules can be controlled by time-varying inhomogeneous electric fields. In a Stark decelerator, this is exploited to select a fraction of a molecular beam that is accelerated, transported, or decelerated. Phase stability ensures that the selected bunch of molecules is kept together throughout the deceleration process. In this paper an extended description of phase stability in a Stark decelerator is given, including higher-order effects. This analysis predicts a wide variety of resonances that originate from the spatial and temporal periodicity of the electric fields. These resonances are experimentally observed using a beam of OH ({sup 2}{pi}{submore » 3/2},v=0,J=3/2) radicals passing through a Stark decelerator.« less
  • A low-energy ion decelerator for the acceleration-deceleration system has been designed and installed in the beam-injection line of the NIRS-930 cyclotron in an attempt to increase the beam intensity from the cyclotron. With this acceleration-deceleration system, the beam intensity of {sup 12}C{sup 4+} ions at the cyclotron exit has been increased by about five times. The system has an advantage in that it allows us to extract a high-current ion beam from an electron cyclotron resonance ion source because, independently of the injection-energy matching to the cyclotron, a large potential difference can be applied between the source and the extractor.more » The voltage applied to the extractor is about -12 kV, which is reduced to the ground potential by the decelerator. The electric field distributions in the deceleration system were carefully designed using a three-dimensional field simulator. Design studies of the decelerator as well as the result of a beam test are presented.« less