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Annual intercomparison of personal dosemeters for neutrons in Germany

At present, four dosimetry services in Germany provide official personal dosemeters for neutron radiation and evaluate these after a certain time of use. For quality assurance, these services are obliged to take part in annual comparison measurements organized and carried out by PTB.

The official personal neutron dosemeter used in Germany is an albedo dosemeter which particularly detects the low-energy neutrons backscattered by the body. The annual comparison irradiations are performed in accordance with the international standard ISO 8529, parts 1 – 3, using our radionuclide neutron sources. The personal dosemeters are irradiated on a PMMA phantom (Fig. 1). In part, also the stray radiation fields behind shadow objects are used (Fig. 2).

Irradiation of personal dosemeters in the field of a D2O moderated 252Cf source with Cd shield (figure left) and with a bare 252Cf source behind shadow cone (figure right)