Operational performance of the SPring-8 storage ring

The SPring-8 storage ring is usually operated with the cycle of three-weeks. The full operation time in one cycle is about 400 hours. About 300 hours are dedicated to users. Since 2001, the four-week cycle is also usually used. Up until now the storage ring completed user service operation of about four years. Over this period the storage ring was operated stably and the total user time reaches more than 12,400 hours, 70% of whole operation time. In order to obtain more brilliant X-rays, we have realized four magnet-free long straight sections (LSS´s) of 27 meters in the storage ring in the summer shutdown of the year 2000. Via smooth machine tuning, the user service operation was successfully started from the beginning of October 2000, keeping almost the same beam performance as that before the LSS´s installation: The estimated horizontal emittance is about 6 nm·rad and the vertical one is at most 14 pm·rad. The beam lifetime is longer than 110 hours in multi-bunch operation. The operational status and recent beam performance of the SPring-8 storage ring will be presented, comparing with that before the LSS´s installation