Development of a strip-shaped X-ray mapping system for 9-cell superconducting cavities

Journal Article · 25 September 2024 · Journal of Instrumentation

DOI: https://doi.org/10.1088/1748-0221/19/09/p09037 · OSTI ID:2472921

Kuriyama, Yasutoshi  ^[1]; Iwashita, Y.  ^[1]; Fuwa, Y.  ^[2]; Tongu, H. ^[1]; Hayano, H.  ^[3]; Geng, R. L.  ^[4]

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1. Kyoto Univ. (Japan)
2. Japan Atomic Energy Agency (JAEA), Tokai (Japan)
3. High Energy Accelerator Research Organization (KEK), Tsukuba (Japan)
4. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

Electrons emitted via field emission during superconducting (SC) radio-frequency (RF) cavity tests at vertical test stands often collide with the iris region inside the cavity, generating X-rays at these locations. In 1.3 GHz 9-cell SC RF cavities designed for the International Linear Collider (ILC), stiffener rings located outside the iris region between cells can interfere with X-ray detection, complicating the precise identification of field emission sites. Hence, in this study, we developed a high-density strip X-ray mapping systems (sX-map) that can be inserted into the iris region of ILC-type 9-cell SC RF cavities. This sX-map facilitates efficient and accurate detection of X-rays generated near the irises, unaffected by the presence of stiffener rings. The sX-map consisted of 32 sensors per strip, with sensors spaced approximately 10 mm apart. It was deployed in every iris of the 9-cell cavity, using a total of 320 sensors. A multiplexer was employed to facilitate the readout of a large number of detectors using a minimal number of signal lines, connecting the strips inside within the vertical test cryostat. In a vertical test conducted at Jefferson Lab (JLab), we demonstrated the capability of sX-map to detect X-rays despite the presence of a stiffener ring. This paper presents the detailed design of the sX-map and the results from the vertical test at JLab.

• Research Organization: Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• Grant/Contract Number: AC05-06OR23177
• OSTI ID: 2472921
• Report Number(s): JLAB-ACC--24-4207; DOE/OR/23177-7698
• Journal Information: Journal of Instrumentation, Journal Name: Journal of Instrumentation Journal Issue: 09 Vol. 19; ISSN 1748-0221
• Publisher: Institute of Physics (IOP)Copyright Statement
• Country of Publication: United States
• Language: English