High power beam at SLAC

The fixed target experiment E-158 has been running with an electron beam close to the highest possible charge and energy available at the Stanford Linear Accelerator Center (SLAC). A charge of 2.5·10¹¹ electrons per pulse at 45 GeV and 30 Hz was routinely delivered for the E-158 commissioning run in April and May, 2001. We have calculated that energies and charges of 45 and 48 GeV with 6.5·10¹¹ and 4.5·10¹¹ particles respectively can be delivered in 370 and 280 ns long beam pulses. Beam loading in the linac was compensated by setting the charge distribution according to a slowly decreasing function, chosen to counteract the rising RF slope of the SLED pulse (SLAC Energy Development). Simultaneous operation with the PEP-II B-Factory posed an additional challenge. Beam pulses with up to 50% different energies had to be accelerated in the linac and then matched to the different beam lines. Pulsed devices have been implemented to enable a fast pulse-by-pulse switching between this beam and the PEP-II injection beams. The commissioning and performance of these devices, along with recent beam measurements are described