Injection System for the Proton Storage Ring at LASL

Abstract

The Proton Storage Ring at LAMPF will accumulate a high current of 800-MeV protons by multiturn charge-changing injection. An 800-MeV neutral hydrogen atomic beam, formed by field ionization of H⁻ ions in a 1.8 T transverse magnetic field, will be stripped to protons by a carbon foil. To minimize peak proton current on the foil, the beam orbit will be deformed so that the edge of the beam grazes the edge of the foil. As the beam diameter grows, the orbit perturbation is decreased, vanishing at the end of the accumulation cycle. The hardware requirements are simple. Single-turn orbit deformation magnets are pulsed to peak field and switched across power dissipation circuits that control the field decay rate.

Stripping foil requirements and a method of calculating the desired orbit deformation are described.

Work performed under the auspices of the US Department of Energy.