Vacuum chamber for the 3 GeV SPEAR injector synchrotron

A 3 GeV booster has been constructed at the Stanford Synchrotron Radiation Laboratory to function as a dedicated, full energy injector into the SPEAR storage ring. Electrons are injected at 120 MeV and accelerated at a cycle rate of 10 Hz to the final energy. The vacuum chamber for this synchrotron has been constructed to avoid eddy current effects due to the rapidly changing magnetic field. The chamber consists of stainless steel tubing of 0.3 mm wall thickness, compressed to an elliptical form, with external stiffening ribs. The suitability of such a vacuum chamber for booster synchrotrons has been tested at cycling rates of up to 15 Hz without intolerable heating or detrimental effects on the magnetic field for the beam. >