SPACE CHARGE EFFECTS FOR THE ERL PROTOTYPE AT DARESBURY LABORATORY

Daresbury Laboratory is currently building an Energy Recovery Linac Prototype (ERLP) that will operate at a beam energy of 35 MeV. In this paper we examine the space charge effects on the beam dynamics in the ERLP transfer line. This is done in two ways. The first is based on an analytic formula derived via the envelope equations and a Kapchinsky-Vladimirsky (KV) distribution. This formula gives an appropriate estimate of the space charge effects in the case that no quadrupoles or dipoles are present in the transfer line. The second estimate is given by the multi-particle tracking code ASTRA for the whole transfer line both with and without quadrupoles. The methods are compared and are found to be in good agreement. Typical examples of beam transfer lines are given together with specific calculations for the ERLP.