Development of an ultra-low energy threshold detector based on superconducting devices and expansion towards drak matter search in the sub-GeV region

2023 Fiscal Year Final Research Report

• Project/Area Number: 20H01927
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 15020:Experimental studies related to particle-, nuclear-, cosmic ray and astro-physics
• Research Institution: University of Tsukuba
• Principal Investigator: Takeuchi Yuji 筑波大学, 数理物質系, 准教授 (00375403)
• Co-Investigator(Kenkyū-buntansha): 藤井 剛 国立研究開発法人産業技術総合研究所, エレクトロニクス・製造領域, 主任研究員 (30709598)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: SOI極低温増幅器 / 超伝導トンネル接合素子 / Sub-GeV暗黒物質探索

Outline of Final Research Achievements

This research aims to develop and make practical use of an ultra-low threshold detector with an energy sensitivity of 100 meV by combining superconducting tunnel junction (STJ) devices and SOI circuits for signal readout at cryogenic temperatures, and to pioneer new sub-GeV regions in dark matter search. As a result of the research, an SOI cryogenic amplifier circuit capable of responding to single photons in the visible to near-infrared range was prototyped and evaluated at room temperature and cryogenic temperatures (3K), confirming its performance as an amplifier under cryogenic conditions. The final evaluation test for signal amplification response combined with the STJ has not been conducted due to a malfunction of the cryogenic refrigerator, but adjustments are being made to the refrigerator, and single-photon response tests in the mid-infrared range are planned.

Free Research Field

素粒子物理学実験

Academic Significance and Societal Importance of the Research Achievements

半導体に比べ，超伝導体素子は桁違いエネルギー分解能を実現し得る潜在性を持つが，極低温冷凍機内での微弱信号読出しの難しさ，大面積・大容量化の不利な点から，物理計測への応用は限定的であるのが現状であるが，それに対し，超伝導体素子と極低温増幅器を組み合わせることで，冷凍機内での微弱信号の増幅読出しにより，超伝導体素子の利便性向上，及び潜在能力を最大限に引き出し，極低エネルギー感度をもつ検出器の可能性を広げることができた。