Author :
Seeman, J.T. ; Biagini, M. ; Cai, Y. ; Decker, F.J. ; Donald, M. ; Ecklund, S. ; Fisher, A. ; Holtzapple, R. ; Iverson, R. ; Kulikov, A. ; Minty, M. ; Novokhatski, A. ; Reichel, I. ; Sullivan, M. ; Turner, J. ; Wienands, U. ; Steier, C. ; Zisman, M. ; Koz
Abstract :
The beam-beam interaction is one of the performance limitations at PEP-II. The peak luminosity in PEP-II has reached 3.4 × 1033 /cm2/s with 693 bunches with a positron current of 1.6 A and an electron current of 0.84 A. The beam-beam tune shift limits have exceeded 0.06 horizontally and 0.03 vertically. A model of the luminosity with current using the measured beam sizes has been developed. Studies are underway to increase the luminosity toward 1034/cm2/s and beyond by increasing the number of bunches, raising the beam currents, lowering the betas at the interaction points, and shortening the bunch lengths
Keywords :
colliding beam accelerators; electron accelerators; particle beam diagnostics; storage rings; PEP-II; beam current; beam size; beam-beam interaction; beam-beam tune shift limits; beta; bunch length; interaction point; luminosity; Contracts; Current measurement; Electron beams; Energy capture; Phase measurement; Positrons; Radio frequency; Size measurement; Testing; US Department of Energy;
