First comparison of spectral responsivity in the soft X-ray region

The first comparison of spectral responsivity scales in the soft x-ray region from 360 eV to 5000 eV has been carried out between the Physikalisch-Technische Bundesanstalt (PTB) and the National Institute of Advanced Industrial Science and Technology (AIST). Two semiconductor photodiodes used as transfer detectors were calibrated using monochromatized synchrotron radiation and cryogenic electrical substitution radiometers as the primary detector standards at these institutes. The primary detector standard at AIST was confirmed to be in agreement with that at PTB at the level of the relative expanded uncertainty. (authors)