A monitor for gamma radiation at zero degrees from the SLC collision point

Abstract

Bremsstrahlung gamma rays are emitted in a narrow forward cone while the electron and positron beams are being measured with carbon fibers at the SLC (the linear collider at the Stanford Linear Accelerator Center). Beam-beam deflections which occur at the collision point also emit softer gamma rays, called beamstrahlung. A device to detect these gammas is described. It has a converter to produce electron-positron pairs and a gas Cherenkov volume to detect them in the presence of a large, low energy, radiation background. The system is used for beam diagnostics at the SLC.