The Joint Accelerator Conferences Website (JACoW) is an international collaboration that publishes the proceedings of accelerator conferences held around the world.
TY - CONF AU - Muto, R. AU - Arakaki, Y. AU - Kimura, T. AU - Matsumura, A. AU - Murasugi, S. AU - Okada, M. AU - Okamura, K. AU - Shimogawa, T. AU - Shirakabe, Y. AU - Tomizawa, M. AU - Toyama, T. AU - Yanaoka, E. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Current Status of Slow Extraction from J-PARC Main Ring J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - A 30 GeV proton beam accelerated in the J-PARC Main Ring (MR) is slowly extracted by the third integer resonant extraction and delivered to the hadron experimental hall. The slow extraction (SX) from the MR has unique characteristics that can be used to obtain a low beam loss rate. A dynamic bump scheme under achromatic condition drastically reduces beam hit rate on the septa devices. We have attained 50 kW SX operation at 5.2s cycle in current physics run. Slow extraction efficiency has been achieved to be very high, 99.5%. A beam instability during debunching with beam loss can be suppressed by a unique RF phase offset technique at MR injection. A spill duty factor indicating a uniformity for time structure of the extracted beam is typically 50%, which can be obtained by a feedback system using fast response quadrupoles, applying transverse RF field and so on. Future plans to improve present SX performances will be introduced. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2311 EP - 2314 KW - extraction KW - operation KW - proton KW - experiment KW - radiation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPMP007 UR - http://jacow.org/ipac2019/papers/wepmp007.pdf ER -