학술논문
Development and operation of an electrostatic time-of-flight detector for the Rare RI storage Ring
Document Type
Working Paper
Author
Nagae, D.; Abe, Y.; Okada, S.; Omika, S.; Wakayama, K.; Hosoi, S.; Suzuki, S.; Moriguchi, T.; Amano, M.; Kamioka, D.; Ge, Z.; Naimi, S.; Suzaki, F.; Tadano, N.; Igosawa, R.; Inomata, K.; Arakawa, H.; Nishimuro, K.; Fujii, T.; Mitsui, T.; Yanagisawa, Y.; Baba, H.; Michimasa, S.; Ota, S.; Lorusso, G.; Litvinov, Yu. A.; Ozawa, A.; Uesaka, T.; Yamaguchi, T.; Yamaguchi, Y.; Wakasugi, M.
Source
Nuclear Inst. and Methods in Physics Research, A 986 (2021) 164713
Subject
Language
Abstract
An electrostatic time-of-flight detector named E-MCP has been developed for quick diagnostics of circulating beam and timing measurement in mass spectrometry at the Rare-RI Ring in RIKEN. The E-MCP detector consists of a conversion foil, potential grids, and a microchannel plate. Secondary electrons are released from the surface of the foil when a heavy ion hits it. The electrons are accelerated and deflected by 90$^\circ$ toward the microchannel plate by electrostatic potentials. A thin carbon foil and a thin aluminum-coated mylar foil were used as conversion foils. We obtained time resolutions of 69(1) ps and 43(1) ps (standard deviation) for a $^{84}$Kr beam at an energy of 170 MeV/u when using the carbon and the aluminum-coated mylar foils, respectively. A detection efficiency of approximately 90% was obtained for both foils. The E-MCP detector equipped with the carbon foil was installed inside the Rare-RI Ring to confirm particle circulation within a demonstration experiment on mass measurements of nuclei around $^{78}$Ge produced by in-flight fission of uranium beam at the RI Beam Factory in RIKEN. Periodic time signals from circulating ions were clearly observed. Revolution times for $^{78}$Ge, $^{77}$Ga, and $^{76}$Zn were obtained. The results confirmed successful circulation of the short-lived nuclei inside the Rare-RI Ring.