scope:

Appropriate techniques for monitoring the radiation conditions during dosimetry measurements or irradiations of biological objects are described. The report also treats specific features of different neutron sources and specific problems of neutron dosimetry in radiobiology and radiotherpy. Appendices to the report provide quantitative information on mass energy transfer coefficients and atomic compositions of compounds and mixtures which is essential for the interpretation of measurements with specific dosimetry systems. Appended also is detailed information on two types of dosimetry systems: ionization chambers and activation and fission detectors. Other appendices give information on properties and fabrication techniques for tissue-equivalent plastics, ionization chamber construction and measurements, and cross-section data for selected threshold reactions. In scope, the report has not been confined to a specific neutron energy range. The clinical use of neutrons generated with accelerators implies that dosimetry may have to be carried out for neutron energies up to and beyond 50 MeV. The report directs attention to dosimetry of the intermediate and thermal neutrons which accompany fast neutrons in extended media. Since the use of primary beams of thermal and intermediate neutrons for biology and medicine is limited, the dosimetry for neutrons with energies below 10 keV is reviewed only briefly.