JACoW is a publisher in Geneva, Switzerland that publishes the proceedings of accelerator conferences held around the world by an international collaboration of editors.
@inproceedings{muto:hb2023-frc1i3,
author = {R. Muto and T. Kimura and A. Matsumura and S. Murasugi and K. Numai and K. Okamura and Y. Shirakabe and M. Tomizawa and E. Yanaoka},
% author = {R. Muto and T. Kimura and A. Matsumura and S. Murasugi and K. Numai and K. Okamura and others},
% author = {R. Muto and others},
title = {{Devices for High-Efficiency Slow Extraction at J-PARC Main Ring}},
% booktitle = {Proc. HB'23},
booktitle = {Proc. 68th Adv. Beam Dyn. Workshop High-Intensity High-Brightness Hadron Beams (HB'23)},
eventdate = {2023-10-09/2023-10-13},
pages = {656--661},
paper = {FRC1I3},
language = {english},
keywords = {septum, extraction, proton, betatron, cathode},
venue = {Geneva, Switzerland},
series = {ICFA Advanced Beam Dynamics Workshop on High-Intensity and High-Brightness Hadron Beams},
number = {68},
publisher = {JACoW Publishing, Geneva, Switzerland},
month = {04},
year = {2024},
issn = {2673-5571},
isbn = {978-3-95450-253-0},
doi = {10.18429/JACoW-HB2023-FRC1I3},
url = {https://jacow.org/hb2023/papers/frc1i3.pdf},
abstract = {{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.}},
}