Fluorescence X-ray field for radiation dosemeters calibration.

An irradiation environment for dosemeters calibration in the fluorescence X-ray field was set up at the Facility of Radiation Standards of the Japan Atomic Energy Agency by re-establishing the fluorescence X-ray calibration field that was established in 1989. The reference air kerma rates were determined using reference ionization chambers calibrated using X-ray narrow-spectrum series calibration field of the national metrology standard in Japan. Since no X-ray calibration field using fluorescence X-rays is available in Japan, the measurements were corrected by factors that accounts for differences in the fluorescence X-ray calibration field energy and the X-ray narrow-spectrum series calibration field energy. The conversion coefficients and correction factors for air densities for the fluorescence X-ray calibration field, including those unavailable in the ISO 4037 standard series, were derived from the measured X-ray fluence rate spectra.