Construction and commissioning of the alternating-gradient synchrotron booster ultrahigh vacuum system

Abstract

The recently completed alternating-gradient synchrotron booster is a synchrotron for the acceleration of both protons and heavy ions. To minimize the beam loss due to charge exchange of the partially stripped, low β(=v/c), very heavy ions with the residual gas molecules, ultrahigh vacuum of 10−11 Torr is required for the 200 m booster ring. An average pressure of mid 10−11 Torr has been achieved and maintained after initial in situ bakes and commissioning. In this article we describe: (1) design and layout of the vacuum systems; (2) material selection and vacuum processing; (3) personal computers/programmable logic controllers based bakeout system; (4) operation of vacuum instrumentation over long cable length; (5) results of bakeout and evaluation; and (6) experience gained during construction and commissioning.