Two particle model for studying the effects of spacecharge force on strong headtail instabilities
In this paper, we present a new two particle model for studying the strong headtail instabilities in the presence of the spacecharge force. It is a simple expansion of the wellknown two particle model for strong headtail instability and is still analytically solvable. No chromaticity effect is included. It leads to a formula for the growth rate as a function of the two dimensionless parameters: the spacecharge tune shift parameter (normalized by the synchrotron tune) and the wakefield strength, Upsilon. The threedimensional contour plot of the growth rate as a function of those two dimensionless parameters reveals stopband structures. Many simulation results generally indicate that a strong headtail instability can be damped by a weak spacecharge force, but the beam becomes unstable again when the spacecharge force is further increased. The new two particle model indicates a similar behavior. In weak spacecharge regions, additional tune shifts by the spacecharge force dissolve the mode coupling. As the spacecharge force is increased, they conversely restore the mode coupling, but then a further increase of the spacecharge force decouples the modes again. Lastly, this mode coupling/decoupling behavior creates the stopband structures.
 Authors:

^{[1]};
^{[2]};
^{[3]}
 KEK High Energy Accelerator Research Organization, Tsukuba (Japan)
 SLAC National Accelerator Lab., Menlo Park, CA (United States)
 Brookhaven National Lab. (BNL), Upton, NY (United States)
 Publication Date:
 Report Number(s):
 BNL1119482016JA
Journal ID: ISSN 24699888
 Grant/Contract Number:
 SC0012704; DEAC0276SF00515; SC00112704; AC0276SF00515
 Type:
 Published Article
 Journal Name:
 Physical Review Accelerators and Beams (Online)
 Additional Journal Information:
 Journal Name: Physical Review Accelerators and Beams (Online); Journal Volume: 19; Journal Issue: 1; Journal ID: ISSN 24699888
 Publisher:
 American Physical Society (APS)
 Research Org:
 SLAC National Accelerator Lab., Menlo Park, CA (United States); Brookhaven National Laboratory (BNL), Upton, NY (United States)
 Sponsoring Org:
 USDOE Office of Science (SC), Nuclear Physics (NP) (SC26)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 43 PARTICLE ACCELERATORS; bunched beam
 OSTI Identifier:
 1235776
 Alternate Identifier(s):
 OSTI ID: 1236569; OSTI ID: 1245390; OSTI ID: 1288315
Chin, Yong Ho, Chao, Alexander Wu, and Blaskiewicz, Michael M. Two particle model for studying the effects of spacecharge force on strong headtail instabilities. United States: N. p.,
Web. doi:10.1103/PhysRevAccelBeams.19.014201.
Chin, Yong Ho, Chao, Alexander Wu, & Blaskiewicz, Michael M. Two particle model for studying the effects of spacecharge force on strong headtail instabilities. United States. doi:10.1103/PhysRevAccelBeams.19.014201.
Chin, Yong Ho, Chao, Alexander Wu, and Blaskiewicz, Michael M. 2016.
"Two particle model for studying the effects of spacecharge force on strong headtail instabilities". United States.
doi:10.1103/PhysRevAccelBeams.19.014201.
@article{osti_1235776,
title = {Two particle model for studying the effects of spacecharge force on strong headtail instabilities},
author = {Chin, Yong Ho and Chao, Alexander Wu and Blaskiewicz, Michael M.},
abstractNote = {In this paper, we present a new two particle model for studying the strong headtail instabilities in the presence of the spacecharge force. It is a simple expansion of the wellknown two particle model for strong headtail instability and is still analytically solvable. No chromaticity effect is included. It leads to a formula for the growth rate as a function of the two dimensionless parameters: the spacecharge tune shift parameter (normalized by the synchrotron tune) and the wakefield strength, Upsilon. The threedimensional contour plot of the growth rate as a function of those two dimensionless parameters reveals stopband structures. Many simulation results generally indicate that a strong headtail instability can be damped by a weak spacecharge force, but the beam becomes unstable again when the spacecharge force is further increased. The new two particle model indicates a similar behavior. In weak spacecharge regions, additional tune shifts by the spacecharge force dissolve the mode coupling. As the spacecharge force is increased, they conversely restore the mode coupling, but then a further increase of the spacecharge force decouples the modes again. Lastly, this mode coupling/decoupling behavior creates the stopband structures.},
doi = {10.1103/PhysRevAccelBeams.19.014201},
journal = {Physical Review Accelerators and Beams (Online)},
number = 1,
volume = 19,
place = {United States},
year = {2016},
month = {1}
}