Experimental investigation of the host medium viscosity effect on formation and stability of bubbles in superheated droplet detector, fabricated using polyacrylamide, in neutron field

The effect of the host medium viscosity of the superheated drop detector on formation and stability of Freon-12 bubbles produced by neutron irradiation has been investigated. By variation of the acrylamide and methylenbisacrylamide concentrations on monomer solution, different polyacrylamide gels with various viscosities of 1 up to 13 Pa-s were prepared. The gels were utilized to prepare the superheated droplet detector. The irradiation results of the prepared superheated droplet detector using an 241Am-Be neutron source and the 2.89 MeV neutrons obtained from the d-d neutron generator showed that the formed bubbles in the fabricated detector, based on non-crosslinked polyacrylamide gel, with the viscosity of 5-6 Pa-s were stable and could be counted after irradiation with the naked eye. The number of bubbles were found to be proportional to the neutron fluence.