Development of a New Dark Matter Detector that Uses Liquid He and Field Ionization

We discuss a new method of dark matter detection[1] that involves He atoms evaporated from a cold surface and their detection using field ionization. When a dark matter particle collides with a liquid He atom it produces phonons and rotons. When these excitations make it to the surface of the liquid He they evaporate a He atom, which can then be detected by ionization in a strong electric field. The >1 meV binding energy of a He atom to the surface opens the door for the detection of dark matter particles with a mass as low as 1 MeV/c². We will discuss the design of the proposed detector as well as the results of preliminary experiments on field ionization. We will also discuss the future of such experiments