136 General As one of the most advanced COEs of photon science in the world, SPring-8 was fully operational during FY2013. The accelerator complex ran reliably with an extremely short downtime of 20 hours and an annual operation time of 4265 hours as described in the following chapters. Due to this excellent availability, the total number of users visiting SPring-8 in FY 2013 for their experiments was 13,381, bringing the total since the inauguration in 1997 to 168,107. By using the achievements of R&D, the electron storage ring began operating with a lower emittance in May 2013. To improve energy efficiency, the cooling water and air- conditioning systems of the accelerator complex were completely renovated in the beginning of 2014. Review At the national level, the Ministry of Education, Culture, Sports, Science and Technology conducted an intensive review of SPring-8 from April–September 2013. According to the offi cial report, the committee identifi ed fi ve priorities for the next fi ve years: (1) SPring-8 should deepen its cooperation with the user community, promote its infrastructure upgrades and users support, expand the user base, and enhance human resource development in related areas. (2) By offering opportunities for technology exchanges, SPring-8, as a COE of Japan, should organically link "knowledge" and "challenge" that universities, research institutes and companies possess, thereby promoting innovative research outcomes. (3) In parallel to strengthening international collaborations, SPring-8 should cooperate with the Photon Beam Platform as well as other Specific Advanced Large Research Facilities in Japan, and attempt to create novel users and to strengthen user support. (4) RIKEN and JASRI, as the owner and the Registered Institution of Facilities Use Promotion of SPring-8, respectively, should enhance their self- inspections in a unifi ed manner. (5) Systematically maintaining its scientific infrastructure further to realize stable operations, SPring-8 should improve its operational efficiency and attempt to elongate its user time. As the Registered Institution of Facilities Use Promotion of SPring-8, JASRI itself also conducted interim reviews for the following contact beamlines; (i) BL07LSU University-of- Tokyo Synchrotron Radiation Outstation (The University of Tokyo), (ii) BL15XU WEBRAM (National Institute for Materials Science), (iii) BL16XU SUNBEAM ID (SUNBEAM Consortium), (iv) BL16B2 SUNBEAM BM (SUNBEAM Consortium), (v) BL24XU Hyogo ID (Hyogo Prefecture), (vi) BL33XU TOYOTA (TOYOTA Central R&D Lab., Inc.), and (vii) BL44XU Macromolecular Assemblies (Institute for Protein Research, Osaka University). In reference to their excellent organizations and outstanding achievements, JASRI approved the continuations of all the beamlines reviewed. International Collaborations When the French President, Monsieur Francois Hollande, visited Japan, there was a signing ceremony held at the French Embassy in Tokyo in June 2013, in order to conclude a Memorandum of Understanding between SOLEIL, RIKEN SPring-8 Center, and JASRI. Also in attendance were Mr. Ichita Yamamoto, Minister of State for Science and Technology Policy, and the French Minister for Higher Education and Research, Mrs. Geneviève Fioraso. To mutually advance research and achievements through regional collaboration, the Asia-Oceania Forum for Synchrotron Radiation Research has played an SPring-8 Signing ceremony held at the French Embassy in Tokyo in June 2013 to conclude a Memorandum of Understanding between SOLEIL, RIKEN SPring-8 Center, and JASRI. Asia-Oceania Forum for Synchrotron Radiation Research 2013 held on September 21-24, 2013 at Himeji. I. Introduction 137 II. Machine Operation The operation statistics for last five fiscal years are shown in Fig. 1. In FY2013, the total operation time of the accelerator complex was 4280.9 h. The operation time of the storage ring was 4265.4 h, 79.9% of which (3408.5 h) was available for SR experiments. The downtime resulting from failure accounted for 0.58% (20 h) of the total user time, and no great loss of user time exceeding several hours occurred. The operation time for FY2013 was about 1000 h less than a typical fiscal year, due to the large-scale renovations of the aging utilities of the cooling water and air-conditioning system. However, with the top-up injection, a high availability (ratio of net user time to the planned user time) was achieved (e.g., 99.3% for FY2013). The total tuning and study time of 852.5 h was used for machine tuning, for the studies of the linac, booster synchrotron and storage ring, and also for the beamline tuning and study. Operations in two different filling modes were provided for the following user time: 54.6% was several-bunch mode, such as the mode of 29 equally spaced trains of 11 bunches) and 45.4% was hybrid filling mode, such as the mode of 1/14-partially filled multi-bunch with 12-isolated bunches. The multi-bunch mode was not operational in FY2013, and the several bunch mode was the predominant filling mode. The 203-bunch mode and the mode of 29 equally spaced trains of 11 bunches reached 25.8% and 28.8% of the total user time, respectively. The new hybrid-filling mode of 11/29-partially filled multi-bunch with a 5.0-mA isolated bunch. For the hybrid filling mode, 1.6 mA, 3.0 mA, or 5.0 mA is stored in each isolated bunch. An isolated bunch impurity better than 10 –10 is routinely maintained in the top-up operation. Table I summarizes of the useful beam parameters of the storage ring, while Table II summarizes the beam filling patterns. important role. Started in 2006 at KEK, Japan, the member states have organized an annual forum. The forum returned to Japan when the Japanese Society for Synchrotron Radiation Research and SPring-8 co-hosted it in combination with the Cheiron School, calling the entire event the Cheiron Week. Honored by the presence of Mr. Kisaburo Tokai, the Chairman of the Special Committee on Promotion of Science and Technology, and Innovation, the House of Representatives, the forum was held September 21-24, 2013 at Himeji. For the 160 participants, the forum was highly informative, especially for young scientists and engineers from the region. Fig. 1. Operation statistics for most recent five fiscal years. 0 1000 2000 3000 4000 5000 6000 Hours FY2012 FY2013 Refill 5.2 Down Time 39.2 Achieved User Time 4155.6 Planning User Time 4200.0 Availability (%) 98.9 5078.8 Accelerator Operation Time 5063.1 Storage Ring Operation Time 884 Tuning & Study (Acc. & BL) 107.7 3.5 20 3408.5 3432.0 99.3 4280.9 4265.4 852.4 214.5 Mean Time Between Failures FY2009 FY2010 FY2011 6.3 5.0 4.4 34.8 27.5 57 4014.9 4071.6 4058.5 4056.0 4104.0 4120.0 99.0 99.2 98.5 5168.8 5125.6 4918.6 5035.4 5096.3 4904.2 1019.1 1026.6 803 122.9 178.4 117.7 Tuning Refill Down Time User Time Energy [GeV] 8 Number of buckets 2436 Tunes ( / ) ν x ν y 40.14 / 19.35 Current [mA]: single-bunch 12 multi-bunch 100 Bunch length ( ) [psec] σ 13 Horizontal emittance [nm • rad] 2.4 * Vertical emittance [pm • rad] 4.8 * Coupling [%] 0.2 RF Voltage [MV] 16 Momentum acceptance [%] Beam size ( σ x / / σ y ) * ) [ μ m] Long ID section 333 / 7 ID section 316 / 5 BM1 section 94 / 12 ~ 3 BM2 section 100 / 12 Beam divergence σ x ' σ y ' [ μ rad] Long ID section 8 / 0.7 ID section 9 / 1.0 BM1 section 58 / 0.5 / BM2 section 68 / 0.5 Operational chromaticities ξ x ξ y +2 / +2 * * Lifetime [h]: 100 mA (multi-bunch) ~ 200 1 mA (single-bunch) ~ 20 Horizontal dispersion [m]: Long ID section 0.153 ID section 0.146 BM1 section 0.039 BM2 section 0.059 Fast orbit stability (0.1 – 200 Hz) horizontal (rms) ~ 4 ~ 1 vertical (rms) * Assuming 0.2% coupling * * With bunch-by-bunch feedback ( / ) * ( [ μ m]: Table I. Beam parameters of SPring-8 storage ring Table II. Filling patterns in FY2013 bunch current (mA) lifetime (h) 203 bunches 0.5 25 ~ 30 11 bunch-train × 29 0.3 35 ~ 50 11/29 - filling + 1 single bunch 1/7 - filling + 5 single bunches 1/14 - filling + 12 single bunches 5.0 (single) 40 ~ 50 3.0 (single) 18 ~ 25 1.6 (single) 18 ~ 25
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