A simple determination of the nuclear mass of deuterium

Many A level syllabuses in chemistry and physics include sections on the Bohr theory of the hydrogen atom as an introduction to atomic structure and interference in thin films, as demonstrated in the Fabry-Perot interferometer. The experiment described in this article clearly demonstrates the effect of finite nuclear mass in modifying the simple Bohr model of single electron atoms and the capability of a February-Perot interferometer to resolve spectral lines differing in wavelength by 10 nm. The experiment therefore forms a useful bridge between the subject areas of atomic physics and optics and illustrates how atomic parameters may be derived from simple macroscopic measurements.