Quenching and channeling of nuclear recoils in NaI(Tl): Implications for dark-matter searches
Abstract
A new experimental evaluation of the quenching factor for nuclear recoils in NaI[Tl] is described. Systematics affecting previous measurements are addressed by careful characterization of the emission spectrum of the neutron source, use of a small scintillator coupled to an ultra-bialkali high-quantum-efficiency photomultiplier, and evaluation of nonlinearities in the electron recoil response via Compton scattering. A trend towards a rapidly diminishing quenching factor with decreasing sodium recoil energy is revealed. Additionally, no evidence for crystal lattice channeling of low-energy recoiling ions is found in a scintillator of known crystallographic orientation. A discussion on how these findings affect dark matter searches employing NaI[Tl] (e.g., DAMA/LIBRA) is offered.
- Publication:
-
Physical Review C
- Pub Date:
- September 2013
- DOI:
- 10.1103/PhysRevC.88.035806
- arXiv:
- arXiv:1302.0796
- Bibcode:
- 2013PhRvC..88c5806C
- Keywords:
-
- 78.70.Ps;
- 29.40.Mc;
- 61.85.+p;
- 95.35.+d;
- Scintillation detectors;
- Channeling phenomena;
- Dark matter;
- Physics - Instrumentation and Detectors;
- Astrophysics - Cosmology and Extragalactic Astrophysics;
- High Energy Physics - Experiment;
- High Energy Physics - Phenomenology
- E-Print:
- 9 pages, 12 figures v2: minor changes only, version submitted to journal