The operation statistics since the facility was opened to users are shown in Fig. 1. In 2009, the total operation time of the accelerator complex was 5025.9 hours. The operation time of the storage ring was 4990.4 hours, of which 79.5% (3967.9 hours) was made available for SR experiments. The down time resulting from failure accounted for 0.87% (34.4 hours) of user time; in 2009, no great 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, a high availability (ratio of net user time to planned user time), e.g., 99.0%, was achieved in 2009. The total tuning and study time of 1023.6 hours was used for machine tuning, for the study of the linac, booster synchrotron and storage ring, and also for beamline tuning and study. Operations in three different filling modes were provided for the following user time: 14.3% in the multi-bunch mode, 40.2% in the several bunch mode, such as the 203-bunch mode (203 equally spaced bunches), and 45.5% in the hybrid filling mode, such as a 1/14-partially filled multi-bunch with 12-isolated bunches. In 2009, the several bunch mode was the dominant filling mode. In particular, the 203-bunch mode reached 23.9% 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 impurity lower than 10 -10 is routinely maintained in the top-up operation. Table I shows a summary of the useful beam parameters of the storage ring. Table II shows a summary of the beam filling patterns. 176 Table I. Beam parameters of SPring-8 storage ring Energy [GeV] 8 Number of buckets 2436 Tunes ( ν x / ν y ) 40.15 / 18.35 Current [mA]: single bunch 12 multi bunch 100 Bunch length ( σ ) [psec] 13 Horizontal emittance [nm·rad] 3.4 * Vertical emittance [pm·rad] 6.8 * Coupling [%] 0.2 RF Voltage [MV] 16 Momentum acceptance [%] Beam size [ μ m]: ( σ x / σ y ) * [ μ m] Long ID section 294 / 10 ID section 301 / 6 BM section 107 / 13 Beam divergence [ μ rad]: ( σ x ' / σ y ' ) * [ μ rad] Long ID section 13 / 0.7 ID section 12 / 1.1 BM section 56 / 0.6 Operatinal chromaticities: ( ξ x / ξ y ) +2 / +6 ** Lifetime [h] : 100 mA (multi-bunch) ~ 200 1 mA (single bunch) ~ 20 Horizontal dispersion [m]: Long ID section 0.103 ID section 0.107 BM section 0.032 Fast orbit stability (0.1 – 200 Hz) [ μ m]: horizontal (rms) ~ 4 vertical (rms) * Assuming 0.2% coupling for “Low Emittance Optics” ** With bunch-by-bunch feedback ± 3 (± 240 MeV) Table II. Filling patterns 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 Accelerator Operation Time Storage Ring Operation Time Tuning & Study (Acc. & BL) Injection Failure User Time Planned Time Availability (%) 2008 1286.0 4189.6 5051.6 5167.5 5456.1 5542.9 5419.5 5759.2 5317.1 5026.2 5027.9 1270.6 4135.4 4863.9 4972.9 5340.6 5484.1 5328.5 5736.7 4781.3 5008.5 5019.2 304 1457.6 1624.2 1815 1276.5 1394.9 1245.8 1085.9 1559.2 1193.6 1100.3 50 110 95.2 70.4 59.3 60.8 39.2 0 0 0 0 26 110 57.2 88.7 87.1 190.5 208.5 82.4 59.7 42.5 27.6 906 2512 3275 3193.4 4033.2 3896.7 3926 4590.9 3698.2 3790.1 3900 984 2712 3432 3352 4176 4152 4176 4680 3762 3840 3936 97.2 96.7 98.2 97.4 98 95.3 95 98.1 98.3 98.7 99.1 5078.5 5063.4 1010 0 30.7 4037.8 4080 99 2009 5025.9 4990.4 1023.6 0 34.4 3967.9 4008 99 0 1000 2000 3000 4000 5000 6000 Hours Tuning & Study Injection Failure UserTime Fig. 1. Operation statistics since the facility became available to users. II. Machine Operation II. Machine Operation bunch current (mA) life time (h) Multi-bunch (160 bunch-train × 12) 0.05 ~ 200 203 bunches 0.5 25 ~ 30 11 bunch-train × 29 0.3 35 ~ 50 1/7 - filling + 5 single bunches 1/14 - filling + 12 single bunches 2/29 - filling + 26 single bunches 4/58 - filling + 53 single bunches 3.0 (single) 18 ~ 25 1.6 (single) 18 ~ 25 1.4 (single) 18 ~ 25 1.0 (single) 18 ~ 25
home
- JP
- EN