Measurement of wavelengths in helium-like sulphur

Abstract

We have used photographic spectroscopy of a beam - foil source to measure the vacuum ultraviolet 1s2s - 1s2p transition wavelengths in helium-like sulphur. The results are A and A, respectively. These measurements, together with our earlier measurements in helium-like silicon and phosphorus, are compared with other precision measurements for Z = 14 to 18, and with recent relativistic and quantum electrodynamic calculations.