Effects of space charge and magnet nonlinearities on beam dynamics in the fermilab booster

Abstract

Presently the Fermilab Booster can accommodate about half the maximum proton beam intensity which the Linac can deliver. One of the limitations is related to large vertical tuneshift produced by space-charge forces at injection energy. In the present report we study the nonlinear beam dynamics in the presence of space charge and magnet imperfections and analyze the possibility of space charge compensation with electron lenses.

On possibility of space-charge compensation in the Fermilab Booster with multiple electron columns

“…The beam space charge was simulated with 197 beam-beam elements distributed around the ring. The charge of an element describing the space charge kick accumulated over distance 𝐿 𝑘 is [2]:…”

“…where 𝐶 = 474.25m is the Booster circumference. The simulations were performed using Mathematica and MAD8 according to the following scheme [2]:…”

“…Using the MAD program, it was shown [2] that a significant (by a factor of 2 or more) transverse emittance blowup may occur in the presence of both space charge and magnetic field errors which break the optics periodicity. The same paper studied the possibility of space charge compensation with a few (1 to 2) electron lenses.…”

“…The question of how many such "columns" are necessary to produce a positive effect arises. To answer it we performed simplified analysis using the same programs as in study [2] (and even the same distribution of magnetic field errors).…”

Beam physics research with the IOTA electron lens

“…Space-charge neutralization and compensation are routinely used in one-pass systems, such as beam lines for low-energy beam transport (LEBT) and rf photoinjectors. In rings, SCC with electrons offers several advantages [32] and could enable higher intensities and brightnesses by reducing losses and emittance growth [51,[53][54][55][56][57][58][59][60]. Proof-of-principle experiments are needed to understand the limits of the method and to explore the stability of the system.…”