Beam quality in single bunch mode of UVSOR ring

The UVSOR storage ring is a synchrotron radiation light source for studies of molecular science and its related fields. The radio frequency of the ring is 90 MHz and its harmonic number is 16. The pulsed light is supplied with a period of 11 ns, when all buckets of the ring are filled. The storage ring can be operated in the single bunch mode when a longer pulse period is required. In this mode, the period of the pulsed light is 180 ns, which is the revolution period of the beam in the ring. The single bunch is produced in the booster synchrotron, and it is transferred to only one bucket of the ring. The usual impurity is 1*10/sup -4/ just after injection at the beam energy of 600 MeV. Bunch lengthening and widening were also measured in this mode. A coupling impedance for the ring of 4 Omega was obtained with this measurement.>