Electron cooling in the presence of undulator fields

Simulating the dynamical friction force on ions due to a briefly co-propagating electron beam

“…(28) and (29) gives exactly the Hermite predictor, Eqs. (16) and (17), up to order Oðh 4 Þ in x i and Oðh 3 Þ in v i . This proves that when E ¼ B ¼ 0, the BCC algorithm converges to the solution to Eq.…”

“…It is reasonable to take j P 1, but we can find no other physical argument for the value of j, and it may differ in other parameter regimes. It has been shown with BETACOOL simulations that this reduction in the friction force, and the associated reduction in electron recombination, can be used to find an optimal undulator field strength [17]. The impact of general fields on the friction force will be explored in much more detail in a future paper.…”

Status of the R&D towards electron cooling of RHIC

“…Simulations for the RHIC cooler based on a realistic electron distribution from the ERL were calculated with BETACOOL [6]. In addition, BETACOOL has been benchmarked against VORPAL for calculations with a helical undulator and the effect on recombination was studied [7].…”

RHIC plans towards higher luminosity

“…There are various RHIC lattice modifications, which result in sufficiently large space available for cooling (about 100 meters) 1231. The cooling section includes modules of a helical undulator to combat recombination of heavy ions with the electron beam as well as several pairs of solenoids to counteract spacecharge defocusing and control the rms angular spread within electron beam to a required level [24].…”

“…The simulated luminosity performance is based on an electron bunch with 5nC charge and 4 pm "effective" emittance (see [24] for details), shown in Fig. 2.…”