First-turn losses in the LAMPF Proton Storage Ring (PSR)
Beam-loss measurements protons injected into the PSR are lost during the first turn. We describe a plausible mechanism, involving field stripping of excited hydrogen atoms, for these losses. Protons are injected into the PSR by transporting a neutral hydrogen beam through a hole in the yoke of one ring bender and then through a carbon foil on the ring axis. The foil strips roughly 93% of the beam atoms to protons. Although the original PSR design assumed that all unstripped atoms would pass through a hole in the yoke of the next downstream bender and on to a beam stop, recent calculations indicate that about 6% of these unstripped atoms will emerge from the foil in an excited state with principle quantum number n{ge}23. These calculations also indicate that atoms in excited states with n{ge}3 will be stripped quickly to protons in the 1.2-Tesla field of the downstream bender. The trajectories of these protons will be outside the phase-space acceptance of the ring and will be quickly lost by collision with the beam pipe, thereby giving rise to first-turn losses. The estimated numbers of protons that would be lost by this mechanism are consistent with the observed first-turn loss rates. This mechanism has important consequences for the design of future storage rings that use neutral atom or negative ion stripping for injection.
- Research Organization:
- Los Alamos National Lab., NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 10159306
- Report Number(s):
- LA-UR--93-1868; CONF-930511--111; ON: DE93014477
- Country of Publication:
- United States
- Language:
- English
Similar Records
First-turn losses in the LAMPF Proton Storage Ring (PSR)
Stripper-foil scan studies of the first-turn beam loss mechanism in the LAMPF proton storage ring (PSR)
Stripper-foil scan studies of the first-turn beam loss mechanism in the LAMPF proton storage ring (PSR)
Conference
·
Thu Dec 31 23:00:00 EST 1992
·
OSTI ID:6385150
Stripper-foil scan studies of the first-turn beam loss mechanism in the LAMPF proton storage ring (PSR)
Conference
·
Tue Jun 01 00:00:00 EDT 1993
·
OSTI ID:10157979
Stripper-foil scan studies of the first-turn beam loss mechanism in the LAMPF proton storage ring (PSR)
Conference
·
Thu Dec 31 23:00:00 EST 1992
·
OSTI ID:6536254