Ion related problems for the XLS ring

Technical Report · Tue Jul 11 00:00:00 EDT 1989

DOI:https://doi.org/10.2172/5606165· OSTI ID:5606165

Bozoki, E; Halama, H ^[1]

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1. Brookhaven National Lab., Upton, NY (USA)

The electron beam in the XLS will collide with the residual gas in the vacuum chamber. The positive ions will be trapped in the potential well of the electron beam. They will perform stable or unstable oscillations around the beam under the repetitive Coulomb force of the bunches. If not cleared, the captured ions will lead to partial or total neutralization of the beam, causing both, a decrease of life-time and a change in the vertical tunes as well as an increase in the tune-spread. They can also cause coherent transverse instabilities. The degree of neutralization {theta} that one can tolerate, is primarily determined by the allowable tune shift, which of the XLS is between 1 and 5 10{sup {minus}3}. Electrostatic clearing electrodes will be used to keep the neutralization below the desired limit. In order to determine their location and the necessary clearing-rate and voltage, we examine the ion production rate, longitudinal velocity of ions in field-free regions and in the dipoles to see what distance the ions can travel without clearing before the neutralization of the beam reaches the prescribed limit, beam potential to see the locations of the potential wells, voltage requirements for ion clearing, critical mass for ion capture in the bunched beam, tune shift caused by neutralization of the beam, pressure rise due to the trapped ions and power dissipation due to beam image current. 13 refs., 3 figs., 4 tabs.

• Research Organization: Brookhaven National Lab. (BNL), Upton, NY (United States)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 5606165
• Report Number(s): BNL-43103; ON: DE90000532; TRN: 89-025697
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
BEAM NEUTRALIZATION
BEAM BUNCHING
BOUNDARY CONDITIONS
CRITICAL MASS
CROSS SECTIONS
ELECTRODES
ELECTRON BEAMS
IONIZATION
SPACE CHARGE
STORAGE RINGS
TUNING
BEAM DYNAMICS
BEAMS
LEPTON BEAMS
MASS
PARTICLE BEAMS
430200* - Particle Accelerators- Beam Dynamics
Field Calculations
& Ion Optics