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TY - CONF AU - Tomizawa, M. AU - Arakaki, Y. AU - Kimura, T. AU - Murasugi, S. AU - Muto, R. AU - Okamura, K. AU - Shirakabe, Y. AU - Yanaoka, E. ED - Schaa, Volker RW TI - Status and Beam Power Ramp-Up Plans of the Slow Extraction Operation at J-Parc Main Ring J2 - Proc. of HB2018, Daejeon, Korea, 17-22 June 2018 C1 - Daejeon, Korea T2 - ICFA Advanced Beam Dynamics Workshop T3 - 61 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. Slow extraction from the MR has unique characteristics that can be used to obtain a low beam loss rate. Devices with electrostatic septum (ESSs) and magnetic septa are placed in the long straight section with zero dispersion. The separatrix for the resonance is independent of the momentum at the septa when the horizontal chromaticity is set to zero. The resulting beam has a large step size and small angular spread, enabling a low hit rate of the beam at the first ESS. Under these conditions, a dynamic bump scheme has been applied to reduce the beam loss further. We have attained 50 kW operation at 5.2s cycle in the latest physics run. A suppression of instability during debunch process is also essential as well as low beam loss tunings. In this paper, a current status and future plans toward a higher beam power for the slow extraction are reported. Preliminary results for a 8 GeV slow extraction test for the muon to electron conversion search experiment (COMET) will be also briefly presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 347 EP - 351 KW - extraction KW - operation KW - septum KW - proton KW - quadrupole DA - 2018/07 PY - 2018 SN - 978-3-95450-202-8 DO - 10.18429/JACoW-HB2018-THA1WD03 UR - http://jacow.org/hb2018/papers/tha1wd03.pdf ER -