Channeling and radiation experiments at SLAC

Over the last years, a SLAC-Aarhus-Ferrara-CalPoly collaboration (augmented by members of ANL and MIT) has performed channeling experiments using bent silicon crystals at the SLAC End Station A Test Beam as well as the FACET accelerator test facility. These experiments have revealed a remarkable channeling efficiency of about 24% under our conditions, as well as shown the dechanneling rate to be independent of the beam energy; an unexpected result. Volume reflection appears to be even more efficient with almost the whole beam taking part in the reflection process. In our most recent experiment we have attempted to measure the spectrum of channeling and volume-reflection gamma radiation. The goal of this series of experiments is to develop a crystalline undulator capable of producing narrow-band gamma rays with electron beams. Such a device could have applications in gamma-ray radiography as well as spectroscopic applications.