Recent developments in fast neutron personnel dosimetry using track etch methods

Direct fast-neutron-induced recoil and (n,α) particle tracks in polymers, in particular Lexan polycarbonate, employing electrochemical etching technique provide a simple, sensitive, and inexpensive method of fast neutron dose measurements. This is considered as an alternative method to the use of NTA films and fission fragment registration technique for fast neutron personnel dosimetry. Response of recoil particle track registration in Lexan polycarbonate as a function of fission neutron dose, directional response, energy dependence, fading characteristics, etc. are given, using electrochemical etching technique. The possibility of proton track registration in polycarbonate is discussed. The direct interaction method covers a wide dose range from 1 mrad to 1000 rads. It is concluded that the technique can be applied for fast neutron personnel dosimetry (routine and criticality accidents), patient monitoring during a neutron therapy trial, and many other health physics and therapy applications. (U.S.)