量子電圧雑音源を用いたボルツマン定数決定

摘要

We have started development of a system to measure thermodynamic temperature which uses electrical quantum standards as references. ITS-90, which is currently used as a practical temperature scale, is based on physical properties of some specific materials such as platinum. In this project, we develop a thermometer based on Johnson-Nyquist theorem. This thermometer will play an important role in determination of Boltzmann constant k， comparison between thermodynamic temperature and ITS-90, and measurement of arbitrary temperature in wide temperature range.%産総研ではジョセフソン電圧標準および量子化ホール抵抗標準を基準とした熱力学温度測定技術の開発に取り組んでいる.現在実用温度計として用いられているITS-90は白金の抵抗の温度依存性のような特定の物質の物性に基づいている.我々はジョセフソン任意波形発生器によって生成される擬似電圧雑音信号を基準としてJohnson-Nyquistの法則から抵抗温度計の熱雑音を精密に計測し、ボルツマン定数の決定や熱力学温度とITS-90との差の評価を行うことを目指している.