Present status of SOR-RING

SOR-RING [1] is the oldest ring that has been constructed as a ring dedicated to synchrotron radiation experiments from the start. Its construction was completed in 1974. The ring is, however, being improved and its accelerator studies are still active. In the 1992 summer shutdown, beam position monitors (BPM's) [2][3][4] were installed in the ring and the BPM system that used PIN diode switches showed a good performance; the relative accuracy was 0.3 to 0.4 μm. Recently the beam lifetime became by a factor of two longer; it was obtained by changing the betatron tunes and by applying a few kV on the ion-clearing electrodes. In this paper, we will present an operational status of the ring and some of recent machine studies [5]. (author)