JACoW is a publisher in Geneva, Switzerland that publishes the proceedings of accelerator conferences held around the world by an international collaboration of editors.
TY - CONF AU - Muto, R. AU - Kimura, T. AU - Matsumura, A. AU - Murasugi, S. AU - Numai, K. AU - Okamura, K. AU - Shirakabe, Y. AU - Tomizawa, M. AU - Yanaoka, E. ED - Cai, Yunhai ED - Nagaitsev, Sergei ED - Kim, Dong Eon ED - Marx, Michaela ED - Schaa, Volker R. W. TI - Devices for High-Efficiency Slow Extraction at J-PARC Main Ring J2 - Proc. of HB2023, Geneva, Switzerland, 09-13 October 2023 CY - Geneva, Switzerland T2 - ICFA Advanced Beam Dynamics Workshop on High-Intensity and High-Brightness Hadron Beams T3 - 68 LA - english AB - J-PARC Main Ring (MR) is a synchrotron that accelerates protons up to 30 GeV and supplies them to the Neutrino Experimental Facility and the Hadron Experimental Facility (HEF). Beam extraction from MR to HEF is performed by slow extraction using third-order resonance. In the slow extraction a device called an electrostatic septum (ESS) is used to scrape out the beam, and it is important to reduce the beam loss at the septum electrode of the ESS in order to supply a high-intensity beam. So far, we have achieved a slow extraction efficiency of 99.5\% by developing an ESS with a thin septum electrode and tuning the bump orbit to reduce the width of the angular distribution of protons at the ESS. In addition, a collimator is installed downstream of the ESS to absorb particles scattered by the septum electrode, thereby reducing activation of the components downstream. In order to achieve further reduction of the beam loss, we are currently considering to install beam diffusers and/or bent silicon crystals at the upstream of the ESS. In this talk, we will present the current status of the slow extraction devices and future plans to further improve the extraction efficiency. PB - JACoW Publishing CP - Geneva, Switzerland SP - 656 EP - 661 KW - septum KW - extraction KW - proton KW - betatron KW - cathode DA - 2024/04 PY - 2024 SN - 2673-5571 SN - 978-3-95450-253-0 DO - doi:10.18429/JACoW-HB2023-FRC1I3 UR - https://jacow.org/hb2023/papers/frc1i3.pdf ER -