Hg198, Kr86の真空波長の測定
1958 年 27 巻 3 号 p. 157-161
詳細
1958 年 27 巻 3 号 p. 157-161
The vacuum wavelengths of three radiations of Hg196 (0.579, 0.577, 0.546 μ) and three of Kr86 (0.646, 0.606, 0.565 μ) are measured in terms of the standard wavelength of red line of Michelson type cadmium lamp, the value of which is taken as 0.644 024 907P deduced from Edlén's formula. A Fabry-Perot etalon consisting of a pair of optical glass flats separated by 62.5 mm invar spacer is used in vacuum to obtain interference fringes. Observations of interference patterns are made photographically with the aid of a high dispersion spectrograph. The results (Table 1) are reported to Comite Consultatif pour la Définition du Métre and show good agreement with those of BIPM, PTB, NPL and NRC (see Table 2)
Hg198: NBS electrodeless Hg'98 lamp containing 3mm Hg argon gas was excited by high frequency power source (200 MHz). The discharge column was viewed from the side through the surrounding water jacket and was kept at temperatures between 0° and 5°C by running water.
Kr86: Engelhard type Kr66 hot cathode lamp cooled in liquid nitrogen was viewed from the end.
