Low background techniques toward a ZnWO4 directionality experiment

Abstract

The ZnWO4 crystal is a very promising scintillator to investigate Dark Matter candidates able to induce just nuclear recoils by exploiting the directionality technique. In particular, the anisotropy of the light output for heavy particles in this scintillator can be considered to point out the presence — in the diurnal counting rate — of a signal produced by such Dark Matter candidates. In this paper the status of art of the performances of recently realized ZnWO4 crystal scintillator is summarized and possible future improvements are discussed. Finally, the directionality approach to pursue this kind of Dark Matter investigation with the anisotropic crystal scintillator is addressed and reachable sensitivities — under given assumptions — in future experiments are discussed.