The coupling impedance of a toroidal beam pipe with circular cross section

Conference · Mon May 01 04:00:00 EDT 1995

OSTI ID:52856

Hahn, H

In this paper, the topic of coupling impedances and beam-induced forces in a toroidal beam pipe is revisited. In straight, smooth accelerator beam pipe configurations, the space charge forces on a charged test particle due to beam-induced electric and magnetic fields are subject to a near perfect cancellation in the ultra-relativistic limit. It is well known that in toroidal geometries the cancellation is imperfect, resulting in residual, ``energy-independent`` longitudinal and transverse forces which can impact the accelerator performance. Whereas the present-day designs of high-energy hadron accelerators/colliders are based on beam pipes with circular cross section, essentially all theoretical studies assume rectangular geometries, the notable exception being the report by Zotter. The expressions here presented are intended to amend this deficiency. An analytic expression for the non-resonant longitudinal coupling impedance in a toroidal beam pipe with circular cross section is derived using a perturbation treatment carried out in a local orthogonal coordinate system.

• Research Organization: Brookhaven National Lab., Upton, NY (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 52856
• Report Number(s): BNL--61223; CONF-950512--9; ON: DE95010442
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
ACCELERATORS
ANALYTICAL SOLUTION
BEAM CURRENTS
BEAM DYNAMICS
CIRCULAR CONFIGURATION
IMPEDANCE
MAXWELL EQUATIONS
PERTURBATION THEORY
SPACE CHARGE
TEST PARTICLES
VACUUM SYSTEMS