ANOMALOUS HIGH RADIATION BEAM ABORTS IN THE PEP-II B-FACTORY

The PEP-II B-Factory at SLAC has recently experienced unexpected beam losses due to anomalously high radiation levels seen in the BaBar detector. The problem was traced to the occurrence of very high (>100 nTorr) pressure spikes that had a very short duration (a few seconds). We describe the events, show analysis predicting where in the vacuum system the events originated, and show what we eventually found to be the source of these vacuum events.