Synchrotron radiation-based bilateral intercomparison of ultraviolet source calibrations

摘要

We report on a successful bilateral intercomparison between the Physikalisch-Technische Bundesanstalt (PTB) and the National Institute of Standards and Technology (NIST). In both laboratories deuterium lamps were calibrated using the calculability of synchrotron radiation. However, the methods applied in the two laboratories differed significantly. Whereas the calibrations at PTB were performed in vacuum and led to spectral radiant intensities, the measurements at NIST were done in air and resulted in spectral irradiances. Therefore, for this bilateral comparison we not only proved the equivalence of the two measurement procedures, but also the validity of the conversion between the different spectro-radiometric quantities. This successful comparison re-establishes the usefulness of deuterium lamps as transfer standards in the ultraviolet spectral range.