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RIS citation export for MOPRB078: Beam Based Measurements of the CBeta Main Linac Cavity Alignment

AU  - Gulliford, C.M.
AU  - Bartnik, A.C.
AU  - Berg, J.S.
AU  - Crittenden, J.A.
AU  - Quigley, P.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Beam Based Measurements of the CBeta Main Linac Cavity Alignment
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Initial attempts at steering the beam through the CBETA main linac indicated the cavities were vertically offset with respect to the BPMs on either side of the linac.  In particular, manual alignment of the beam in the first and last cavities suggested a vertical offset of roughly 5 mm.  This work presents the results of beam based measurements of the individual cavity offsets taken during the CBETA Fractional Arc Test.  With only a single cavity powered at a time, beam was injected at several different vertical offsets, the RF phase was scanned over 360 degrees, and the beam position was measured at the end of the cryomodule. We analyzed the data in two ways. We first compute the RMS spread in the measurements at a given position, and considered the offset with the minimum RMS spread to be the cavity offset. We also fit the measurements at a given phase to a line as a function of initial displacement, and use a model for the transfer matrix of the cavity and downstream drift to compute the offset. The two methods agree well, resulting in an average vertical offset of the main linac cavities of 4.0 plus/minus 1 mm.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 755
EP  - 757
KW  - cavity
KW  - linac
KW  - cryomodule
KW  - survey
KW  - acceleration
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-MOPRB078
UR  - http://jacow.org/ipac2019/papers/moprb078.pdf
ER  -