IBIC2022 - List of Authors (Igarashi, S.)

Paper	Title	Page
WEP21	Merits of Pulse Mode Operation of Residual Gas Ionization Profile Monitor for J-PARC Main Ring	434
	K. Satou, Y. Sato J-PARC, KEK & JAEA, Ibaraki-ken, Japan S. Igarashi KEK, Ibaraki, Japan
	Funding: Accelerator and Beamline Research and Technology Development for High-Power Neutrino Beams in the U.S.-Japan Science and Technology Cooperation Program in High Energy Physics. The measurement accuracy of the ionization profile monitor (IPM) of J-PARC main ring (MR) depends on the flatness and stability of the gain of the position-sensitive microchannel plate (MCP). The flatness of the MCP deteriorates after long-term operation; the gain of the central area selectively decreases as the integrated output charge increases. The beam-based calibration, where the local bump shifts the beam and the reconstructing beam profiles determine the gain distribution, is used to calibrate the flatness. The immediate gain drop occurs when the output current from the MCP becomes comparable to the bias current is problematic. This gain drop depends on the bias voltage and the output current; thus, it is difficult to calibrate. A pulsed HV module of 30 kV, which collects ionized electrons and ions, was installed to solve these problems. The pulse mode operation can modulate the averaged output current from the MCP to improve gain stability. Profiles of the intense beam up to 3.3·10¹³ ppb were measured and compared with those measured by destructive profile monitors in beam transport lines 3’50 BT, and the Abort line. Estimated emittances were consistent at ±20%.
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2022-WEP21
About •	Received ※ 07 September 2022 — Revised ※ 10 September 2022 — Accepted ※ 12 September 2022 — Issue date ※ 16 October 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Merits of Pulse Mode Operation of Residual Gas Ionization Profile Monitor for J-PARC Main Ring

434

K. Satou, Y. Sato
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
S. Igarashi
KEK, Ibaraki, Japan

Funding: Accelerator and Beamline Research and Technology Development for High-Power Neutrino Beams in the U.S.-Japan Science and Technology Cooperation Program in High Energy Physics.
The measurement accuracy of the ionization profile monitor (IPM) of J-PARC main ring (MR) depends on the flatness and stability of the gain of the position-sensitive microchannel plate (MCP). The flatness of the MCP deteriorates after long-term operation; the gain of the central area selectively decreases as the integrated output charge increases. The beam-based calibration, where the local bump shifts the beam and the reconstructing beam profiles determine the gain distribution, is used to calibrate the flatness. The immediate gain drop occurs when the output current from the MCP becomes comparable to the bias current is problematic. This gain drop depends on the bias voltage and the output current; thus, it is difficult to calibrate. A pulsed HV module of 30 kV, which collects ionized electrons and ions, was installed to solve these problems. The pulse mode operation can modulate the averaged output current from the MCP to improve gain stability. Profiles of the intense beam up to 3.3·10¹³ ppb were measured and compared with those measured by destructive profile monitors in beam transport lines 3’50 BT, and the Abort line. Estimated emittances were consistent at ±20%.

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2022-WEP21

About •

Received ※ 07 September 2022 — Revised ※ 10 September 2022 — Accepted ※ 12 September 2022 — Issue date ※ 16 October 2022

Cite •

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