Individual neutron dosimetry

Neutron dosemeters capable of being worn on the body fall into two classes: (a) dosemeters for record purposes: (b) alarm dosemeters providing an immediate response to changes in the neutron fields. Historically individual neutron records have been based upon (n, γ) reactions in the cadmium-covered film badges, for thermal and intermediate energy neutrons, and proton track counting in photographic emulsions for fast neutrons. Albedo dosemeters based upon thermoluminescent detectors have been widely used for a variety of neutron fields. The solid state track detectors have provided more precise measurements of all type of neutron fields. The interesting Canadian development of the bubble detector potentially provides an immediately observable response and then the detector can be used as a record of total dose equivalent received. Personal alarm dosemeters for neutrons have proved to be difficult and expensive to produce. However, ingenious solutions have been produced including microdosimetric counters and microprocessor controlled electronics. All the different types of detector and operating systems to provide an estimate of the neutron dose equivalent to an individual are discussed and their value assessed. (author)