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Response of a dielectric microcalorimeter operating with a feed-back of detection pulse signa

介电微量热计的响应与检测脉冲信号的反馈操作

基本信息

批准号：
14380237
负责人：
MAEHATA Keisuke
金额：
$ 6.08万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

项目摘要

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

微量热计通过保持在低于1 K的低温下的吸收体中的温度升高来检测单个辐射粒子。灵敏温度计是微量热计的重要组成部分。0.99SrTiO_3-0.01SrTa_2O_6介电材料的电容具有温度依赖性，在200 mK以下有最小值。电容的温度依赖性可用于微量热计的灵敏温度计。通过施加恒定的DC电压，电容的变化改变了存储在介电电容器中的电荷。在介电微量热计中，由入射辐射引起的温度升高被转换成与介电材料的电容变化成比例的电荷。由于介质器件中没有电流流过，所以介质微热计具有抑制约翰逊噪声和焦耳热产生的优点。 ...更多信息设备中的离子。材料的电容d（lnC_d）/dT的温度依赖性是介电温度计的重要参数。制备了0.99SrTiO_3-0.01SrTa_2O_6介质样品。在100 mK时，样品的d（lnC_d）/dT的实验值为-2.02。然而，用0.99SrTiO_3 - 0.01SrTa_2 O_6介质样品制成的原型温度计的d（lnC_d）/dT值没有获得重现性。经过多次研究发现，0.99SrTiO_3-0.01SrTa_2O_6介电材料中SrO和TiO_2的非化学计量比对d（lnC_d）/dT在1 K以下的行为有影响。我们采用0.99SrTiO_3-0.01SrTa_2O_6介质材料制作了一台介质微量热计样机。利用无氦小型稀释制冷机将介质微热量计冷却到100 mK以下后，用~（40）Am源发射的α粒子辐照介质微热量计<241>。介电微量热计检测到5.5 MeV的α粒子。通过施加110 V的偏置电压，在电荷敏感型三极管的输出处，检测信号的脉冲高度为1.6 V。在这项研究中，我们展示了潜在的优异的检测性能的介电微量热计。少