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Title: High Precision RF Control for SRF Cavities in LCLS-II

Abstract

The unique properties of SRF cavities enable a new generation of X-ray light sources in XFEL and LCLS-II. The LCLS-II design calls for 280 L-band cavities to be operated in CW mode with a Q_{L} of 4x10⁷, using Single-Source Single-Cavity control. The target RF field stability is 0.01% and 0.01 degree for the band above 1 Hz. Hardware and software implementing a digital LLRF system has been constructed by a four-lab collaboration to minimize known contributors to cavity RF field fluctuation. Efforts include careful attachment to the phase reference line, and minimizing the effects of RF crosstalk by placing forward and reverse signals in chassis separate from the cavity measurement. A low-noise receiver/digitizer section will allow feedback to operate with high proportional gain without excessive noise being sent to the drive amplifier. Test results will show behavior on prototype cryomodules at FNAL and JLab, ahead of the 2018 final accelerator installation.

Authors:
;
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
OSTI Identifier:
1457161
Report Number(s):
FERMILAB-CONF-17-671-AD
1669556
DOE Contract Number:  
AC02-07CH11359
Resource Type:
Conference
Resource Relation:
Conference: 18th International Conference on RF Superconductivity, Lanzhou, China, 07/17-07/21/2017
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS

Citation Formats

Doolittle, Lawrence, and et al. High Precision RF Control for SRF Cavities in LCLS-II. United States: N. p., 2018. Web. doi:10.18429/JACoW-SRF2017-FRXBA02.
Doolittle, Lawrence, & et al. High Precision RF Control for SRF Cavities in LCLS-II. United States. doi:10.18429/JACoW-SRF2017-FRXBA02.
Doolittle, Lawrence, and et al. Mon . "High Precision RF Control for SRF Cavities in LCLS-II". United States. doi:10.18429/JACoW-SRF2017-FRXBA02. https://www.osti.gov/servlets/purl/1457161.
@article{osti_1457161,
title = {High Precision RF Control for SRF Cavities in LCLS-II},
author = {Doolittle, Lawrence and et al.},
abstractNote = {The unique properties of SRF cavities enable a new generation of X-ray light sources in XFEL and LCLS-II. The LCLS-II design calls for 280 L-band cavities to be operated in CW mode with a Q_{L} of 4x10⁷, using Single-Source Single-Cavity control. The target RF field stability is 0.01% and 0.01 degree for the band above 1 Hz. Hardware and software implementing a digital LLRF system has been constructed by a four-lab collaboration to minimize known contributors to cavity RF field fluctuation. Efforts include careful attachment to the phase reference line, and minimizing the effects of RF crosstalk by placing forward and reverse signals in chassis separate from the cavity measurement. A low-noise receiver/digitizer section will allow feedback to operate with high proportional gain without excessive noise being sent to the drive amplifier. Test results will show behavior on prototype cryomodules at FNAL and JLab, ahead of the 2018 final accelerator installation.},
doi = {10.18429/JACoW-SRF2017-FRXBA02},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2018},
month = {Mon Jan 01 00:00:00 EST 2018}
}

Conference:
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