Comparative studies of the response of BR-100R bubble and CR-39 based neutron detectors for personnel neutron dosimetry

A breakthrough occurred in neutron dosimetry in 1978 and 1979 when the track recording properties of CR-39 and superheated drop detectors were reported. A related superheated detector, the so-called bubble detector was reported in 1984 and is now commercially available as BD-100R. Both BD-100R and CR-39 based cubical detectors have been used in a variety of monitoring applications around nuclear reactors, fusion sources, etc. The responses of BD-100R and CR-39 based cubical neutron dosemeters have been studied and compared in free air and on a water phantom for personnel neutron dosimetry purposes. All the detectors were irradiated with monoenergetic neutrons having energies from 0.144 MeV to 14.6 MeV as well as portable neutron sources including a heavy water moderated 252Cf neutron source. After irradiation, CR-39 detectors were etched chemically for 6 h in 6M NaOH at 70oC followed by 3 h electrochemical etching in the same etchant at 60oC applying 50 kV.cm-1 peak-to-peak at a frequency of 2 kHz. Results indicate that despite possessing some promising properties, the BD-100R detector cannot replace CR-39 based personnel neutron dosemeters but they can complement each other. (Author)