Successful Beam-Beam Tuneshift Compensation

Landau Damping of Beam Instabilities by Electron Lenses

“…Moreover, the electron current can be easily regulated over short time intervals and the electron lenses can be set to operate on a subset of least stable bunches in the accelerator or even on individual bunches, as was demonstrated in the Tevatron [20]. The increased betatron frequency spread δν of about 0.004-0.01 induced by the electron lenses has been demonstrated in the 980 GeV proton beam in the Tevatron [21] and in the RHIC 100…”

Electron lenses: historical overview and outlook

“…Such richness and flexibility of the electron lenses have attracted researchers, leading to many inventive proposals, studies and theses, such as, e.g., [7][8][9][10][11][12][13][14][15]. The use of focusing space-charge forces of magnetically confined electron cloud in beam transport lines was first proposed by D.Gabor in 1947 [16] -see Fig.…”

“…Electron lenses in pulsed operation, enabled by the availability of high voltage modulators with fast rise times, can be synchronized with individual proton bunches or subsets of bunches and provide highly selective effects for each subset; electron beam stability: in a typical electron lens configuration, electrons are produced at the cathode of an electron gun and right after passing the interaction area get damped in a collector; thus, fresh electrons interact with the high-energy particles on each turn, leaving no possibility for coherent instabilities, similar to those that are driven by the electron clouds or other insufficiently controlled charge formations. Such richness and flexibility of the electron lenses have attracted researchers, leading to many inventive proposals, studies and theses, such as, e.g., [7][8][9][10][11][12][13][14][15]. The use of focusing space-charge forces of magnetically confined electron cloud in beam transport lines was first proposed by Gabor in 1947 [16] -see figure 3a.…”