Potential dark matter detector?:the detection of low energy neutrons by superfluid 3He

Bradley, DI and Bunkov, YM and Cousins, DJ and Enrico, MP and Fisher, Shaun and Follows, MR and Guénault, A.M. and Hayes, WM and Pickett, George and Sloan, T (1995) Potential dark matter detector?:the detection of low energy neutrons by superfluid 3He. Physical review letters, 75 (10). pp. 1887-1890. ISSN 0031-9007

Abstract

Using an existing experiment we have demonstrated in a pilot study that superfluid He-3 at 100 mu K can be used as a nuclear recoil detector sensitive to neutron and gamma interactions depositing energies down to a few hundred eV. The deposited energy is converted to He-3 quasiparticles which are detected by their damping effect on a vibrating wire resonator in the liquid. The system can be calibrated independently but a convenient fixed point is provided by the exothermic reaction n + He-3(2) = p + H-3(1) + 764 keV. Given the great potential for improvement we propose that the system might make a sensitive weakly interacting massive particle detector.