Beam Diagnostics of the Tristan Accumulation Ring

The beam diagnostic system of the TRISTAN Accumulation Ring consists of beam position monitors, visible radiation monitors, x-ray monitors, tune measurement setup, etc.. Eighty-six position monitors are installed around the ring. For the closed orbit measurement, a superheterodyne circuit is used to pick up the 479-th harmonic of the revolution frequency (795 kHz) out of beam pulse trains. Synchrotron light is observed in the visible region and in the x-ray region. Visible radiation is used in three ways: profile monitoring by TV cameras, beam current measurement and bunch shape observation by a streak camera. In the x-ray channel a multi-wire ionization chamber is used to get a digitized profile of the x-ray source. Stripline pickxps are installed to detect transverse oscillations of e+ and e- bunches. The envelope signal of pulse trains will be sent to an FFT processor for tune number identification. At the same time the signals are amplified and fed back to wideband deflection electrodes for damping of the oscillaitons.