Development of a calculable capacitor

This paper summarizes the current NIST effort to manufacture a new calculable capacitor, focusing on issues associated with the fabrication of the main electrodes and their alignment as well as development of a high resolution Fabry-Perot interferometer system for displacement measurements of the calculable capacitor. Results presented here for diamond turned aluminum electrodes show useable profiles that deviate from straight by less than 25 nm. We have also achieved a fractional uncertainty of ~1.25×10^-9 for displacement measurements without any optical frequency standard.