ELECTRON COOLING USING A PULSED AND DITHERING BEAM FROM AN ELECTROSTATIC ELECTRON COOLER

Conference · Mon Nov 01 00:00:00 EDT 2021

DOI:https://doi.org/10.18429/JACoW-COOL2021-P1008· OSTI ID:1842280

Wang, Haipeng ^[1]; Benson, Steve ^[1]; Hutton, Andrew ^[1]; Jordan, Kevin ^[1]; Powers, Tom ^[1]; Rimmer, Robert A. ^[1]; Satogata, Todd ^[1]; Sy, Amy V. ^[1]; Bruker, Max ^[1]; Wang, S. ^[1]; Zhang, H. ^[1]; Zhang, Y. ^[1]; Li, J. ^[2]; Ma, F. ^[2]; Ma, X. M. ^[2]; Mao, L. J. ^[2]; Sha, X. P. ^[2]; Yang, J. C. ^[2]; Yang, X. D. ^[2]; Zhao, H. W. ^[2] ; Zhao, H. ^[3]

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1. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
2. Lanzhou Univ. (China)
3. Brookhaven National Lab. (BNL), Upton, NY (United States)

Electron cooling continues to be an invaluable technique to reduce and maintain the emittance in hadron storage rings such as the EIC and EICC where stochastic cooling is inefficient and radiative cooling is negligible. Extending the energy range of electron coolers beyond what is feasible with the conventional, electrostatic approach necessitates the use of RF fields for acceleration and, thus, a bunched electron beam. To experimentally investigate how the relative time structure of the two beams affects the cooling properties, we have set up a pulsed-beam cooling device by adding a synchronized pulsing circuit to the conventional electron source of the CSRm cooler at Institute of Modern Physics. Using both constant and modulated synchronization between electron pulses and ion bunches, we have measured the effects of the electron bunch length and longitudinal ion focusing strength on the temporal evolution of the longitudinal and transverse ion beam profile and demonstrated the detrimental effect of timing jitter as predicted by space-charge theory and simulations. Our experiment suggests a need for further investigations of specific aspects of bunched cooling such as synchro-betatron coupling and phase dithering effects when using short electron bunches to cool longer ion bunches. However, given the comparatively long IBS lifetime of higher-energy proton storage rings like the EIC, slow dithering could potentially provide an option to save cost on the electron cooler linac.

• Research Organization: Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• DOE Contract Number: AC05-06OR23177
• OSTI ID: 1842280
• Report Number(s): JLAB-ACC-21-3550; DOE/OR/23177-5372; P1008
• Resource Relation: Conference: COOL 2021, 1-5 November 2021, Budker INP, Novosibirsk (virtual)
• Country of Publication: United States
• Language: English