The Joint Accelerator Conferences Website (JACoW) is an international collaboration that publishes the proceedings of accelerator conferences held around the world.
@InProceedings{harkay:napac2019-moplm21,
author = {K.C. Harkay and J.R. Calvey and J.C. Dooling and L. Emery and R.R. Lindberg and K.P. Wootton and C. Yao},
% author = {K.C. Harkay and J.R. Calvey and J.C. Dooling and L. Emery and R.R. Lindberg and K.P. Wootton and others},
% author = {K.C. Harkay and others},
title = {{Circuit Model Analysis for High Charge in the APS Particle Accumulator Ring}},
booktitle = {Proc. NAPAC'19},
pages = {151--154},
paper = {MOPLM21},
language = {english},
keywords = {impedance, injection, booster, synchrotron, photon},
venue = {Lansing, MI, USA},
series = {North American Particle Accelerator Conference},
number = {4},
publisher = {JACoW Publishing, Geneva, Switzerland},
month = {10},
year = {2019},
issn = {2673-7000},
isbn = {978-3-95450-223-3},
doi = {10.18429/JACoW-NAPAC2019-MOPLM21},
url = {http://jacow.org/napac2019/papers/moplm21.pdf},
note = {https://doi.org/10.18429/JACoW-NAPAC2019-MOPLM21},
abstract = {The Advanced Photon Source (APS) particle accumulator ring (PAR) was designed to accumulate linac pulses into a single bunch with a fundamental rf system, and longitudinally compress the beam with a harmonic rf system prior to injection into the booster. For APS Upgrade, the injectors will need to supply full-current bunch replacement with high single-bunch charge for swap-out in the new storage ring. Significant bunch lengthening, energy spread, and synchrotron sidebands are observed in PAR at high charge. Lower-charge dynamics are dominated by potential well distortion, while higher-charge dynamics appear to be dominated by microwave instability. Before a numerical impedance model was available, a simple circuit model was developed by fitting the measured bunch distributions to the Haissinski equation. Energy scaling was then used to predict the beam energy sufficient to raise the instability threshold to 18-20 nC. With the beam in a linear or nearly linear regime, higher harmonic radio frequency (rf) gap voltage can be used to reduce the bunch length at high charge and better match the booster acceptance.},
}