Toward a determination of the fine structure constant at LNE by means of a new Thompson-Lampard calculable capacitor

摘要

This paper reports on the current development of a new Thompson-Lampard calculable capacitor at LNE. The goal is to determine the von Klitzing constant R_K at a significant level of uncertainty of about one part in 10 ~8. The comparison with other accurate measurements of h/e~2 serves as a relevant test of validity of the theory predicting R_K = h/e ~2, a decisive issue within the context of the new SI. Conversely, assuming that this relation is exact, the measurement of R_K and thus that of the fine structure constant can be used for testing quantum electrodynamics theory. The mechanical structure of the new LNE calculable cross capacitor has been designed and a new set of electrodes has been fabricated. The assembling of the calculable capacitor is in progress.