JACoW is a publisher in Geneva, Switzerland that publishes the proceedings of accelerator conferences held around the world by an international collaboration of editors.
@inproceedings{zacarias:srf2023-mopmb090,
author = {L.M. Zacarias and S. Aderhold and A.T. Cravatta and M.A. Drury and D. Gonnella and J.P. Holzbauer and J.T. Maniscalco and M.D. McCaughan and J. Nelson and R.D. Porter and S. Posen and C.M. Wilson},
% author = {L.M. Zacarias and S. Aderhold and A.T. Cravatta and M.A. Drury and D. Gonnella and J.P. Holzbauer and others},
% author = {L.M. Zacarias and others},
title = {{Measuring Q₀ in LCLS-II Cryomodules Using Helium Liquid Level}},
% booktitle = {Proc. SRF'23},
booktitle = {Proc. 21th Int. Conf. RF Supercond. (SRF'23)},
pages = {327--331},
eid = {MOPMB090},
language = {english},
keywords = {cavity, cryomodule, linac, MMI, SRF},
venue = {Grand Rapids, MI, USA},
series = {International Conference on RF Superconductivity},
number = {21},
publisher = {JACoW Publishing, Geneva, Switzerland},
month = {09},
year = {2023},
issn = {2673-5504},
isbn = {978-3-95450-234-9},
doi = {10.18429/JACoW-SRF2023-MOPMB090},
url = {https://jacow.org/srf2023/papers/mopmb090.pdf},
abstract = {{The nitrogen-doped cavities used in the Linac Coherent Light Source II (LCLS-II) cryomodules have shown an unprecedented high Q₀ in vertical and cryomodule testing compared with cavities prepared with standard methods. While demonstration of high Q₀ in the test stand has been achieved, maintaining that performance in the linac is critical to the success of LCLS-II and future accelerator projects. The LCLS-II cryomodules required a novel method of measuring Q₀, due to hardware incompatibilities with existing procedures. Initially developed at Jefferson Lab during cryomodule acceptance testing before being used in the tunnel at SLAC, we use helium liquid level data to estimate the heat generated by cavities. We first establish the relationship between the rate of helium evaporation from known heat loads using electric heaters, and then use that relationship to determine heat from an RF load. Here we present the full procedure along with the development process, lessons learned, and reproducibility while demonstrating for the first time that world record Q₀ can be maintained within the real accelerator environment.}},
}