Toward a determination of the fine structure constant at LNE by means of a new Thompson–Lampard calculable capacitorThis paper was presented at the International Conference on Precision Physics of Simple Atomic Systems, held at École de Physique, les Houches, France, 30 May – 4 June, 2010.
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 RK at a significant level of uncertainty of about one part in 108. The comparison with other accurate measurements of h/e2 serves as a relevant test of validity of the theory predicting RK = h/e2, a decisive issue within the context of the new SI. Conversely, assuming that this relation is exact, the measurement of RK and thus that of the fine structure constant α 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.