HB2023 - List of Authors (Numai, K.)

Paper	Title	Page
FRC1I3	Devices for High-Efficiency Slow Extraction at J-PARC Main Ring	656
	R. Muto, T. Kimura, S. Murasugi, K. Numai, K. Okamura, Y. Shirakabe, M. Tomizawa, E. Yanaoka KEK, Ibaraki, Japan A. Matsumura Nihon Advanced Technology Co., Ltd, Ibaraki, Nakagun, Tokaimura, Japan
	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.
	Slides FRC1I3 [3.167 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-FRC1I3
About •	Received ※ 18 October 2023 — Revised ※ 19 October 2023 — Accepted ※ 23 October 2023 — Issued ※ 01 November 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Devices for High-Efficiency Slow Extraction at J-PARC Main Ring

656

R. Muto, T. Kimura, S. Murasugi, K. Numai, K. Okamura, Y. Shirakabe, M. Tomizawa, E. Yanaoka
KEK, Ibaraki, Japan
A. Matsumura
Nihon Advanced Technology Co., Ltd, Ibaraki, Nakagun, Tokaimura, Japan

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.

Slides FRC1I3 [3.167 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-FRC1I3

About •

Received ※ 18 October 2023 — Revised ※ 19 October 2023 — Accepted ※ 23 October 2023 — Issued ※ 01 November 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)