First experimental results of the frequency dependence of a Vacuum-Gap Capacitor between 1 kHz and 0.02 Hz

This paper describes the first results of an experiment aiming to determine the frequency dependence of a cryogenic vacuum-gap capacitor between 0.01 Hz (`DC´) and 1 kHz (AC). The AC-`DC´ difference of the vacuum-gap capacitor is measured as a function of temperature, and the measured change of around 23 μF/F between 273 K and 4 K agrees well with an extrapolation of earlier measurements on the same capacitor between 100 Hz and 1 kHz. The results also seem to support estimates that the AC-`DC´ difference of this capacitor is well below 1 μF/F at 4 K.