Measurements of the intensity distribution of microstructure beam pulses from an isochronous cycIotron are described. Typical intensity distributions resuIt in an increase ofthe chance coincidence rate of coincidence experiments by a factor of 2 over the ideal case of equally sized bursts. Among other factors stray frequencies in the rf may contribute to these intensity fluctuations.
151For a normalized intensity distribution h(l) the chance coincidences are given byh(l) = (j (I-I o ), N chO = clczI~.