Jefferson Lab, Newport News, Virginia
Microwave instability of an electron beam can be used for a multiple increase in the collective response for the perturbation caused by a particle of a co-moving ion beam, i.e. for enhancement of friction force in electron cooling method. The low scale (hundreds GHz and larger frequency range) space charge or FEL type instabilities can be produced (depending on conditions) by introducing an alternating magnetic fields along the electron beam path. Beams’ optics and noise conditioning for obtaining a maximal cooling effect and related limitations will be discussed. The method promises to increase by a few orders of magnitude the cooling rate for heavy particle beams with a large emittance for a wide energy range with respect to either electron and conventional stochastic cooling [1,2].
[1] Ya. S.Derbenev, Coherent Electron Cooling, UM HE 91-28, August 7, 1991[2] Ya. S.Derbenev, AIP Conf. Proc., No 253, p. 103. AIP 1992
Jefferson Lab, Newport News, Virginia
An electron-ion collider (EIC) of center mass energy 90 GeV (9 GeV of electron beam x 225 GeV of proton beam) at luminosity level up to 1035/cm2s is envisioned by high energy Nuclear Physics community as a facility adequate for studying of the fundamental properties of quark-gluon structure of nucleons and strong interactions. In response to this quest, a high luminosity ring-ring EIC design (ELIC) is developed at Jefferson Laboratory utilizing 12 GeV upgrade CEBAF accelerator as a full energy injector for electron storage ring . An inevitable component of EIC is high energy electron cooling (EC) for ion beam. The EC facility concept for ELIC is based on use of 30 mA, 125 MeV energy recovery linac (ERL) and 3A circulator-cooler ring (CCR) operated at 15 and 1500 MHz bunch repetition rate, respectively. To switch electron bunches between ERL and CCR, fast kickers of a frequency bandwidth above 2 GHz are designed. The design parameters of EC facility and preliminary results of study of electron beam transports, stability and emittance maintenance in ERL and CCR, together with scenario of forming and cooling of ion beam will be presented.