Beam Monitors Based on Light Observation for the Beam Switchyard of the Stanford Two-Mile Linear Accelerator

This paper describes three monitors and the associated optical system used to observe the profile of the high-power electron beam in the switchyard of the two-mile linear accelerator. One device is based on the observation of synchrotron light emitted by the beam when deflected in the analyzing magnets. The second type uses the Cerenkov light produced in a gas cell which is inserted into the beam path when needed. The third type uses conventional zinc sulfide screens with a mechanism for replacing a screen which has become inactive, with a new screen. Reflective optics systems and closed circuit television are used to transmit the images of the beam spots to T.V. monitors in the control room.