Author :
Allen, M.A. ; Breidenbach, M. ; Augustin, J.-E. ; Boyarski, A. ; Davies-White, W. ; Dean, N. ; Fischer, G. ; Harris, J.L. ; Karvonen, L. ; Larsen, R.R. ; Lee, M.J. ; Lynch, H.L. ; McConnell, R. ; Morton, P. ; Paterson, J.E. ; Rees, J. ; Richter, B. ; Sabe
Abstract :
Measurements of luminosity at SPEAR, which were performed at different operational conditions of the storage ring are shown and discussed. The parameters varied are: the current in both beams, the minimum betatron amplitude functions at the collision point, the energy and the vertical betatron frequencies. As a result of these measurements we found that the maximum achievable luminosity is much higher than predicted by the incoherent beam-beam limit using ¿v = 0.025. We also found that the maximum achievable luminosity is a strong function of the betatron frequencies. After computing the largest linear tuneshifts, we found that the quarter resonance seems to be the limiting effect for beam-beam collision.
