Diagnostics For Recirculating And Energy Recovered Linacs

Abstract

In this paper, the electron beam diagnostics developed for recirculating electron accelerators will be reviewed. The main novelties in dealing with such accelerators are: to have sufficient information and control possibilities for the longitudinal phase space, to have means to accurately set the recirculation path length, and to have a means to distinguish the beam passes on measurements of position in the linac proper. The solutions to these problems obtained at Jefferson Laboratory and elsewhere will be discussed. In addition, more standard instrumentation (profiling and emittance measurements) will be reviewed in the context of recirculating linacs. Finally, and looking forward, electron beam diagnostics for applications to high current energy recovered linacs will be discussed.

Beam Diagnostics for the BNL Energy Recovery Linac Test Facility

“…The ERL imposes diagnostics requirements [3,4] beyond those normally present in linacs and storage rings. One such requirement is to measure with high resolution the difference in currents between the accelerated and decelerated beams.…”

“…A method [3] which is similar in principle but not yet demonstrated in practice, would center the two beams relative to each other by looking at a conventional BPM output at the RF fundamental and second harmonic and tuning to minimize the fundamental and maximize the second harmonic. Phasing for the acceleration pass can be accomplished by measuring beam position and/or profile in dispersive regions.…”