| Project/Area Number |
14380237
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Nuclear engineering
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| Research Institution | Kyushu University |
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Principal Investigator |
MAEHATA Keisuke KYUSHU UNIVERSITY, Faculty of Engineering, Associate Professor, 大学院・工学研究院, 助教授 (30190317)
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| Co-Investigator(Kenkyū-buntansha) |
ISHIBASHI Kenji KYUSHU UNIVERSITY, Faculty of Engineering, Professor, 大学院・工学研究院, 教授 (00159766)
ARIMA Hidehiko KYUSHU UNIVERSITY, Faculty of Engineering, Research Associate, 大学院・工学研究院, 助手 (20253495)
SHIGYO Nobuhiro KYUSHU UNIVERSITY, Faculty of Engineering, Research Associate, 大学院・工学研究院, 助手 (40304836)
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| Project Period (FY) |
2002 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥9,500,000 (Direct Cost: ¥9,500,000)
Fiscal Year 2004: ¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 2003: ¥2,700,000 (Direct Cost: ¥2,700,000)
Fiscal Year 2002: ¥4,700,000 (Direct Cost: ¥4,700,000)
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| Keywords | Cryogenic Particle detector / High performance X-ray detector / Microcalorimete / Dielectric Device / Low Temperature Control / 温度制御 / マイクロカロリーメータ |
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| Research Abstract |
The microcalorimeter detects a single particle of radiation by means of the temperature rise in the absorber kept at low temperatures below 1 K. A sensitive thermometer is important component in the microcalorimeter. The electric capacitance of 0.99SrTiO_3-0.01SrTa_2O_6 dielectric materials exhibits the temperature dependence and the minimum value below 200 mK. The temperature dependence of the electric capacitance can be utilized for the sensitive thermometer of the microcalorimeter. By applying a constant DC voltage, a change in the electric capacitance alters the electric charge stored in the dielectric capacitor. In the dielectric microcalorimeter, the temperature rise induced by the incident radiation is converted to the electric charge proportional to the change in the electric capacitance of the dielectric material. Because of no current-flow across the dielectric device, the dielectric microcalorimeter has advantage of suppression of the Johnson noise and the Joule heat generat
… More
ion in the device. The temperature dependence of electric capacitance d(ln C_d)/dT of the material is important parameter for the dielectric thermometer. We fabricated 0.99SrTiO_3-0.01SrTa_2O_6 dielectric samples. The experimental value of d(ln C_d)/dT of the dielectric sample was -2.02 at 100mK. However reproducibility in values of d(ln C_d)/dT was not obtained for prototype thermometers made of 0.99SrTiO3-0.01SrTa2O6 dielectric samples. After several researches, the behavior of the value of d(ln C_d)/dT below 1K was found to be affected by a nonstoichiometry between SrO and TiO_2 in 0.99SrTiO_3-0.01SrTa_2O_6 dielectric materials. We fabricated a prototype dielectric microcalorimeter using 0.99SrTiO_3-0.01SrTa_2O_6 dielectric materials. After cooled down below 100 mK by operating a liquid helium-free compact dilution refrigerator, the dielectric microcalorimeter was irradiated by alpha particles emitted from ^<241>Am source. The dielectric microcalorimeter detected 5.5 MeV alpha particles. By applying the bias voltage of 110 V, the pulse height of the detection signal was 1.6 V at the output of a charge sensitive preamplifier. In this study, we demonstrated potential of excellent detection performance of the dielectric microcalorimeter. Less
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