R&D ERL: Diagnostics

Abstract

The Energy Recovery Linac (ERL) prototype project is currently under development at the Brookhaven National Laboratory. The ERL is expected to demonstrate energy recovery of high intensity beams with a current of up to a few hundred milliamps, while preserving the emittance of bunches with a charge of a few nanocoulombs produced by a high current SRF gun. To successfully accomplish this task the machine will include beam diagnostics that will be used for accurate characterization of the three dimensional beam phase space at the injection and recirculation energies, transverse and longitudinal beam matching, orbit alignment, beam current measurement, and machine protection. This report outlines requirements on the ERL diagnostics and describes its setup and modes of operation. The BNL Prototype ERL is an R&D effort aimed at reducing risks and costs associated with the proposed RHIC II electron cooler and eRHIC collider. The ERL will serve as a test bed for developing and testing instrumentation and studying physics and technological issues relevant to very high current ERL's. The prototype ERL, mated to a high current SRF gun, is expected to demonstrate production and energy recovery of high intensity, low emittance beams with a current of up to a few hundred milliamps. To successfully accomplish this task the ERL will include beam diagnostics required to characterize and tune beam parameters, as well as for machine protection. A preliminary diagnostics plan was presented in earlier publications. In this report, we describe the diagnostics presently planned to provide the data needed to meet these goals.