Radiation Protection Dosimetry 28:21-28 (1989)
© 1989 Oxford University Press
Can Individual Dosemeters for the Measurement of the Direction Dose Equivalent H'(10) Indicate Organ Doses and the Effective Dose Equivalent?
Individual dosemeters have recently been designed to indicate the directional dose equivalent H'(10). Whenever recorded doses exceed dose limits it is of interest to interpret the dosemeter reading in terms of organ dose equivalents and the effective dose equivalent HE. Secondary dose quantities for dose limitation and calibration were found by using the ICRP 51 conversion factors for the dose equivalent in the skin HSk, the lens of the eye HLe, the testes HTe, the ovaries HOv, the female breast HBr, the lung HLu, the red bone-marrow HBm and the effective dose equivalent H'E calculated for the MIRD phantom. LiF dosemeters, flat phosphate glass dosemeters and pen ionisation dosemeters were calibrated in the photon energy range 15 keV to 1.2 MeV on the surface of the ICRU phantom. With respect to the indication of HSk, HLe, HTe and in particular H'E the results in the energy range above 30 keV have been found to be energy independent to the order of ± 20%. In the energy range below 30 keV the dosemeters may under-estimate HSk and HLe, but over-estimate HTe, HOv, HLu, HBm and H'E significantly. The over-estimation of H'E and organ dose equivalents is, however, lower in practice, in particular for pen dosemeters, phosphate glass dosemeter systems using two readout modes or TLD systems with two different shielded detectors. Dosemeters designed for monitoring H'(10) may allow indication of H'E and organ dose equivalents, in general for photon energies above 60 keV, in particular above 15 keV. The use of organ dose equivalents for the calibration of individual dosemeters would reduce the significant over-response of H'(10) in the energy range below 50 keV.