First measurement of the ionization yield of nuclear recoils in liquid argon

T H Joshi; S Sangiorgio; A Bernstein; M Foxe; C Hagmann; I Jovanovic; K Kazkaz; V Mozin; E B Norman; S V Pereverzev; F Rebassoo; P Sorensen

doi:10.1103/PhysRevLett.112.171303

First measurement of the ionization yield of nuclear recoils in liquid argon

Phys Rev Lett. 2014 May 2;112(17):171303. doi: 10.1103/PhysRevLett.112.171303. Epub 2014 May 1.

Authors

T H Joshi¹, S Sangiorgio², A Bernstein², M Foxe³, C Hagmann², I Jovanovic⁴, K Kazkaz², V Mozin², E B Norman¹, S V Pereverzev², F Rebassoo², P Sorensen²

Affiliations

¹ Department of Nuclear Engineering, University of California, Berkeley, California 94720, USA and Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
² Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
³ Lawrence Livermore National Laboratory, Livermore, California 94550, USA and Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
⁴ Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.

PMID: 24836233
DOI: 10.1103/PhysRevLett.112.171303

Abstract

This Letter details a measurement of the ionization yield (Q(y)) of 6.7 keV(40)Ar atoms stopping in a liquid argon detector. The Q(y) of 3.6-6.3 detected e(-)/keV, for applied electric fields in the range 240-2130 V/cm, is encouraging for the use of this detector medium to search for the signals from hypothetical dark matter particle interactions and from coherent elastic neutrino-nucleus scattering. A significant dependence of Q(y) on the applied electric field is observed and explained in the context of ion recombination.