S801
ORNL RAD, Oak Ridge, Tennessee, USA
JLab, Newport News, Virginia, USA
ODU, Norfolk, Virginia, USA
A high-current electron storage-ring cooler is proposed to cool ion beams in a collider to reduce the beam emittance and compensate the emittance degradation due to the intra-beam scattering (IBS) effect. Such a storage ring cooler is consisted of two sections with significantly different energies: the low energy section is designed for an optimum cooling of ion beams and the high energy section is optimized for desired damping parameters of electron beams. An energy recovering superconducting RF structure is used to provide the necessary energy change. Beam dynamics in this two-energy storage ring is different from and more complicated than it in a single energy system. This paper presents the linear optics design and particle tracking simulation results. IBS time versus damping time and optimization of beam parameters are also discussed in this paper.
JLab, Newport News, Virginia, USA
IMP/CAS, Lanzhou, People’s Republic of China
BNL, Upton, New York, USA
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.
P1009
JLab, Newport News, Virginia, USA
The intrabeam scattering can affect the accumulation, the lifetime, and the property of a high-intensity beam. Electron cooling is a method to mitigate the intrabeam scattering effect. JSPEC (JLab Simulation Package on Electron Cooling) is an open-source program developed at Jefferson Lab, which includes various numerical models and friction force formulas for intrabeam scattering and electron cooling simulations. JSPEC has been benchmarked with BETACOOL and experimental data. In this report, we will introduce what features JSPEC provides to the users and how it carries out the computations. Numerical examples are presented to demonstrate the performance and the validity of JSPEC.