Luminosity monitor using the coherent beam-beam interaction

At the Cornell Electron/Positron Storage Ring, a fast luminosity monitor has been implemented. The monitor works by measuring the amplitude of oscillation of selected bunches while the corresponding opposing bunches are shaken. Signal-to-noise ratios of better than 100:1 have been obtained with 1 sec averaging times. A software normalization program ameliorates the unwanted dependence of the signal upon certain vertical lattice parameters such as the vertical tune