A bubble-damage polymer detector for neutrons

A sensitive neutron detector has been developed using an elastic-solid polymer in which tiny droplets of superheated liquid are uniformly dispersed. When neutrons strike the detector, the recoiling nuclei trigger the volatilizing of the individual droplets. The resulting bubbles, visible to the naked eye, are immobilized by the medium and can be counted to give a measure of the neutron dose. Over a period of weeks the bubbles can fade due to diffusion of gas into the medium, but they can be made to reappear because the initial process of bubble expansion has left damage sites in the medium which serve as centres for bubble re-activation. (author)