CBETA: a 4-pass superconducting ERL with permanent FFA magnet return arc

20 Nov 2019, 09:00
WBGB/019 (TimeOut)



Paul Scherrer Institute Forschungsstrasse 111 CH-5232 Villigen PSI Switzerland


Stephen Brooks (BNL)


Beam commissioning is currently in progress for the CBETA ERL recently built at Cornell University in collaboration with BNL. This machine has a 6MeV injector and 36MeV main superconducting RF module at ~1.3GHz frequency. The beam is designed to pass through the main RF up to four times accelerating and four times decelerating, before being dumped at 6MeV. These four energies (42, 78, 114, 150MeV) are returned to the RF by a racetrack FFA return loop of permanent magnets. These magnets have been designed so that all four energies are stably transported through the same R=25mm good field aperture. Between the RF and return loop on either side, the four energies are split apart for adjustment to tune energy recovery and optics performance. At the date of writing, beam has made one turn energy recovery through the permanent magnet loop at 42MeV including orbit correction to <1mm.

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