Study of collective effects for the APIARY collider

Conference · Fri Sep 01 04:00:00 EDT 1989

OSTI ID:7248038

Zisman, M S

The design of a high-luminosity electron-positron collider to study B-physics is a challenging task from many points of view. In this paper we consider the influence of collective effects on the machine performance; most of our findings are generic,'' in the sense that they depend rather weakly on the details of the machine design. Based upon an example machine design (APIARY-II), we investigate single-bunch thresholds for the longitudinal microwave and transverse mode-coupling instabilities, examine the possibility of emittance growth from intrabeam scattering, calculate the beam lifetime from Touschek scattering and gas scattering, and estimate the growth rates for both longitudinal and transverse coupled-bunch instabilities. We find that the single-bunch instabilities should not lead to difficulty, and that the emittance growth is essentially negligible. At a background gas pressure of 10 nTorr, beam lifetimes of only a few hours are expected, which will place a burden on the injection system if a high average luminosity is to be maintained. Even this lifetime is likely to require an innovative design for the vacuum system to maintain a pressure of 10 nTorr in the presence of a circulating electron or positron beam of approximately 1 A. With a standard PEP-like multicell rf system, multibunch growth rates are very severe, especially in the longitudinal plane. There appear to be significant benefits to a radically different rf system design, either utilizing superconducting single-cell rf cavities, or cavities with equivalent geometrical shapes but operated at room temperature. Even then, a powerful feedback system will likely be required. Nonetheless, it does not appear that there are any fundamental problems that stand in the way of successfully designing and building such a high-luminosity B-Factory. 13 refs., 9 figs., 5 tabs.

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 7248038
• Report Number(s): LBL-27676; CONF-8906210--5; ON: DE90008493
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
430200* -- Particle Accelerators-- Beam Dynamics
Field Calculations
& Ion Optics
B MESONS
BEAM BUNCHING
BEAM DYNAMICS
BEAM EMITTANCE
BEAM-BEAM INTERACTIONS
BEAMS
BOSONS
COLLIDING BEAMS
ELECTRON-POSITRON INTERACTIONS
ELEMENTARY PARTICLES
HADRONS
INSTABILITY
INTERACTIONS
LEPTON-LEPTON INTERACTIONS
MESONS
PARTICLE INTERACTIONS
PSEUDOSCALAR MESONS
RF SYSTEMS
SCATTERING
STORAGE RINGS
VACUUM SYSTEMS