Further research on the NIM's new vertical calculable cross-capacitor with latest optimal hollow active auxiliary electrode

摘要

The latest optimal hollow active auxiliary electrode (OHAAE) has been developed and adopted in the NIM's new vertical calculable cross-capacitor (VCCC) since 2018. The further research including the additional function of the latest OHAAE for the dissemination experiment, the robustness of the best compensation voltage ratio $k_{ext{best}}$ in the actual VCCC and the improvement of the laser interferometry system is investigated. After the re-evaluation for the frequency coefficient, the standard uncertainty of reproducing 1 pF capacitance unit from the NIM's new VCCC with the latest OHAAE applying the $k_{ext{best}}$ is estimated as $10.0imes 10^{-9}$.