216 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 Accelerator Operation Time 1286.0 4189.6 5051.6 5167.5 5456.1 5542.9 5419.5 5759.2 5317.1 5026.2 5027.9 Storage Ring Operation Time 1270.6 4135.4 4863.9 4972.9 5340.6 5484.1 5328.5 5736.7 4781.3 5008.5 5019.2 Tuning & Study (Acc. & BL) 304 1457.6 1624.2 1815 1276.5 1394.9 1245.8 1085.9 1559.2 1193.6 1100.3 Injection 50 110 95.2 70.4 59.3 60.8 39.2 0 0 0 0 Failure 26 110 57.2 88.7 87.1 190.5 208.5 82.4 59.7 42.5 27.6 User Time 906 2512 3275 3193.4 4033.2 3896.7 3926 4590.9 3698.2 3790.1 3900 Planned Time 984 2712 3432 3352 4176 4152 4176 4680 3762 3840 3936 Availability (%) 97.2 96.7 98.2 97.4 98 95.3 95 98.1 98.3 98.7 99.1 0 1000 2000 3000 4000 5000 6000 Hours Tuning & Study Injection Failure UserTime Fig. 2. Operation statistics since the facility became available to users. The operation statistics since the facility was opened to users are shown in Fig. 2. In 2007, the total operation time of the accelerator complex was 5027.9 hours. The operation time of the storage ring was 5019.2 hours, of which 77.7% (3900 hours) was made available to the users. The downtime resulting from failure accounted for 0.7% (27.6 hours) of the operation time of the storage ring; in 2007, no considerable loss of user time exceeding several hours occurred. Since 2004, there has been no injection time because top-up injection was introduced. Concerning user service operation, the high availability (ratio of net user time to planned user time) achieved, e.g., 99.1% in 2007. The total tuning and study time of 1100.3 hours was used for machine tuning, and the study of the linac, booster synchrotron and storage ring, and also for the beamline tuning and study. Operations in three different filling modes were provided for the following user time: percentages 17% in the multi-bunch mode, 51.9% in the several bunch mode, such as the 203-bunch mode (203 equally spaced bunches) and 31.1% in the hybrid filling mode such as a 1/7- partially filled multi-bunch with 5- isolated bunches. In 2007, several bunch mode was the dominant filling mode. In particular, the 203-bunch mode reached 31.7% of the total user time. For the hybrid filling mode, 1.0 mA, 1.4 mA, 1.6 mA, or 3.0 mA is stored in each isolated bunch. An isolated bunch purity better than 10 -10 is routinely maintained in the top-up operation. Table I shows a summary of the beam filling patterns. Table II shows a summary of the useful beam parameters of the storage ring. Machine Operation Machine Operation
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