Preliminary measurements of radiation from a critical assembly using the bubble detector

Neutron dose measurements from a critical assembly were made using the newly developed bubble detector. These detectors were still in an experimental stage and had to be compensated for a temperature dependence; however, the results obtained compared favourably with those pre-determined by theoretical calculations and previous instrumentation. It was found that the neutron bubble detector was totally insensitive to photons and was convenient and fast to use. The fact that the detectors yielded results immediately after exposure and were isotropic in response make the mapping of neutron distributions quite a simple task