A METHOD OF OBTAINING PARASITIC E(-) BEAMS DURING SLAC LINEAR COLLIDER OPERATION() OR E()

We have developed a technique that allows SLAC to provide parasitic lo w-intensity secondary e+ and e- beams up to 25 GeV to End Stations A a nd B and to the FFTB during SLC operation. This beam was successfully used for a one-month-long experimental run in End Station A by the SLA C E-146 collaboration. The experiment used 400 MeV to 25 GeV electron beams at intensities averaging one electron per pulse and 120 pulses p er second. The method for producing such a beam without the need for d edicated beam time was to operate parasitically from SLC: photons prod uced in the SLC beam scrapers in linac sectors 28, 29 and 30 were conv erted to positrons and electrons in a target downstream from the SLC s plitter magnet. The secondary electrons or positrons were then transpo rted to ESA with the A-line.