Streak camera measurements of the longitudinal distribution with multiple bunches in CESR

Abstract

The Cornell Electron-Positron Storage Ring (CESR) has a longitudinal dipole-coupled-bunch instability that limits the total amount of current that can be stored in the ring. As a result, it is one of the major limitations for higher luminosity [1]. This paper reports the results from a streak camera used to measure the dependence of the bunch's distribution on current and accelerating RF voltage for multiple bunches in CESR, as well as the effects of the longitudinal instability on the bunch distribution. Measurements of the bunch's longitudinal distribution at CESR, with multiple bunches present in the ring, help give an understanding of the nature of the longitudinal instability.