During this Phase I effort, Proportional Technologies, Inc. will develop non-saturating components for a military battlefield dosimeter based on ionization chamber technology, which will ultimately be combined with low-dose sensors in Phase II for a final product that is both highly sensitive, accurate, and non-saturating in the event of a nuclear blast or other high-dose scenario. The proposed high-dose components will be thimble-shaped ionization chambers, with one component made of conductive A150 plastic doped with boron, sensitive to both high-energy and low-energy neutrons. A second component will be constructed from graphite and sensitive to gammas only, allowing for the subtraction of the gamma signal from the neutron channel so that the gamma and neutron signals can be accurately measured independently. Additional designs will be devised which will enable threshold activation detection of fast neutrons for extended-time measurement of the fast neutron component in the event of electronic disruption. When design and manufacture of the Phase I high-dose detectors are complete, the high-dose sensors will be tested in a controlled criticality experiment at a government facility.
