Eur. Phys. J. A (2020) 56: 83
https://doi.org/10.1140/epja/s10050-020-00094-z

Special Article – New Tools and Techniques

Measurements of anisotropic response to nuclear recoils for the ADAMO project

¹ INFN sezione Roma “Tor Vergata”, 00133, Rome, Italy
² Dipartimento di Fisica, Università di Roma “Tor Vergata”, 00133, Rome, Italy
³ INFN sezione Roma, 00185, Rome, Italy
⁴ Dipartimento di Fisica, Università di Roma “La Sapienza”, 00185, Rome, Italy
⁵ INFN, Laboratori Nazionali del Gran Sasso, 67100, Assergi, AQ, Italy
⁶ ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, C.R. Casaccia, 00123, Rome, Italy
⁷ Institute for Nuclear Research of NASU, Kyiv, 03028, Ukraine

^* e-mail: rita.bernabei@roma2.infn.it

Received: 26 December 2019
Accepted: 17 February 2020
Published online: 12 March 2020

Abstract

Anisotropic scintillators can offer a unique possibility to exploit the so-called directionality approach in order to investigate the presence of those Dark Matter (DM) candidates inducing nuclear recoils. In fact, their use can overcome the difficulty of detecting extremely short nuclear recoil traces. In this paper we present recent measurements performed on the anisotropic response of a crystal scintillator to nuclear recoils, in the framework of the ADAMO project. The anisotropic features of the crystal scintillators were initially measured with particles; those results have been also confirmed by the additional measurements presented here. The experimental nuclear recoil data were obtained by using a neutron generator at ENEA-CASACCIA and neutron detectors to tag the scattered neutrons; in particular, the quenching factor values for nuclear recoils along different crystallographic axes have been determined for three different neutron scattering angles (i.e. nuclear recoils energies). From these measurements, the anisotropy of the light response for nuclear recoils in the crystal scintillator has been determined at 5.4 standard deviations.