================================================================ J-PARC Project Newsletter Special Issue Japan Proton Accelerator Research Complex under construction jointly by the High Energy Accelerator Research Organization (KEK) and the Japan Atomic Energy Agency (JAEA) http://j-parc.jp/index-e.html ================================================================ Successful beam acceleration up to 30 GeV at the 50-GeV Synchrotron (MR) of J-PARC The J-PARC 50-GeV Synchrotron (MR) has successfully accelerated the proton beams and extracted them to a beam dump. The first beam commissioning of the MR started on the 22nd of December, 2008. Next day, the 23rd of December, at 17:34, the beam was accelerated to 30 GeV, which is the target energy of the first stage of J-PARC, and was extracted intentionally to the abort beam dump. The MR is the first large accelerator in the world designed with an imaginary transition energy. Preliminary results show that small beam loss occurred in the first several hundreds of milliseconds, then no significant current drop was observed until the beam extraction. The acceleration time was 2.5 seconds in this run. Further beam tuning is in progress. The next step for the MR is the extraction to the hadron experimental hall (January 2009) and to the neutrino beam line (April 2009). ----------------------------------------------------------- [Editorial Note] ----------------------------------------------------------- In case you do not wish to receive this Newsletter in the future, please send an email to news-l-ctl@ml.j-parc.jp and simply write one sentence in the body of the message as unsubscribe If you wish to receive, write one sentence in the body of the message as subscribe You can get a help with a sentence of "help" in the body. Information on the project can be also obtained at the Web site: http://j-parc.jp/index-e.html +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Editorial Board: Masatoshi ARAI (chair): masatoshi.arai@j-parc.jp Yujiro IKEDA: ikeda.yujiro@jaea.go.jp Nobuo OUCHI: ouchi.nobuo@jaea.go.jp Shinya SAWADA: shinya.sawada@kek.jp Toshifumi TSUKAMOTO: toshifumi.tsukamoto@kek.jp English Editor: Dick MISCHKE mischke@triumf.ca Secretary: Chikako KAIBARA kaibara.chikako@jaea.go.jp ++++++++++++++++End of Letter+++++++++++++++++++++++++++++++