Quantitative investigation of gamma radiation in accelerator produced ISO neutron fields.

In standard monoenergetic ISO neutron fields, the neutron yield of neutron-producing reactions was measured in combination with the prompt photon yield, including photon energies up to 10 MeV, for the purpose of comparing the two yields. Separating the photons produced by the target (direct photons) from those generated by secondary neutron reactions was achieved using the time-of-flight method. Photon and neutron ambient dose equivalent values were calculated from measured spectral energy distributions.

Comparison of the conversion method with gravel unfolding to obtain dose values from photon spectra.

Modern gamma-ray spectrometers based on solid-state scintillators are increasingly being used in fields where previously dosemeters were applied. From the spectra, precise fluence and dose information can be derived. The most important methods of doing this are investigated in detail; the conversion method, which is based on weighing functions; and unfolding, here using the GRAVEL algorithm.

THE GERMAN DOSE RATE MONITORING NETWORK AND IMPLEMENTED DATA HARMONIZATION TECHNIQUES.

Environmental radiation monitoring networks have been established in Europe and world-wide for the purpose of protecting population and environment against ionizing radiation. Some of these networks had been established during the cold war period and were improved after the Chernobyl accident in 1986. Today, the German Federal Office for Radiation Protection (BfS) operates an early warning network with roughly 1800 ambient dose equivalent rate (ADER) stations equally distributed over the German territory.

ON THE CONVERSION COEFFICIENT FROM AIR KERMA TO AMBIENT DOSE EQUIVALENT VALID FOR A CS-137 PHOTON FIELD-A CRITICAL REVIEW.

In radiation protection, the quantity ambient dose equivalent, in short H*(10), is very important in the field of area dosimetry, because this quantity is used to estimate the effective dose to human beings, whose permissible limits are restricted by law. The conversion coefficient from air kerma to H*(10), valid for a 137Cs photon field, is essential as it enters the realization of the quantity H*(10) as well as every (directly or indirectly) related calibration. The basic calibration factor of any dose rate instrument is usually related to a calibration in a 137Cs photon field, which underlines the importance of the conversion coefficient discussed in this article.

Novel spectrometers for environmental dose rate monitoring.

A new generation of dosemeters, based on the scintillators LaBr, CeBr and SrI, read out with conventional photomultipliers, to be used in the field of environmental gamma-radiation monitoring, was investigated. The main features of these new instruments and especially their outdoor performance, studied by long-term investigations under real weather conditions, are presented. The systems were tested at the reference sites for environmental radiation of the Physikalisch-Technische Bundesanstalt.