First demonstration of a sub-keV electron recoil energy threshold in a liquid argon ionization chamber

We describe the first demonstration of a sub-keV electron recoil energy threshold in a dual-phase liquid argon time projection chamber. This is an important step in an effort to develop a detector capable of identifying the ionization signal resulting from nuclear recoils with energies of order a fe...

Full description

Saved in:
Bibliographic Details
Published in:Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Accelerators, spectrometers, detectors and associated equipment, 2013-11, Vol.728, p.69-72
Main Authors: Sangiorgio, S., Joshi, T.H., Bernstein, A., Coleman, J., Foxe, M., Hagmann, C., Jovanovic, I., Kazkaz, K., Mavrokoridis, K., Mozin, V., Pereverzev, S., Sorensen, P.
Format: Article
Language:English
Subjects:
Argon
Calibration
Calibration sources
Detectors
Electron recoils
Energy (nuclear)
Ionization
Ionization yield
Liquid argon
Liquids
Recoil
Sub-keV spectroscopy
Thresholds
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We describe the first demonstration of a sub-keV electron recoil energy threshold in a dual-phase liquid argon time projection chamber. This is an important step in an effort to develop a detector capable of identifying the ionization signal resulting from nuclear recoils with energies of order a few keV and below. We obtained this result by observing the peaks in the energy spectrum at 2.82keV and 0.27keV, following the K- and L-shell electron capture decay of 37Ar respectively. The 37Ar source preparation is described in detail, since it enables calibration that may also prove useful in dark matter direct detection experiments. An internally placed 55Fe x-ray source simultaneously provided another calibration point at 5.9keV. We discuss the ionization yield and electron recombination in liquid argon at those three calibration energies. •We measure sub-keV electron recoils in a dual-phase argon time projection chamber.•Ar-37 is produced via neutron irradiation and used as calibration source.•Ar-37 electron captures at 2.82 and 0.27keV are measured together with Fe-55 x-rays.•Spurious single ionization electrons provided absolute calibration of charge signal.•Modified Thomas–Imel model describes low-energy electron-recoils in liquid Ar.
ISSN:0168-9002
1872-9576
DOI:10.1016/j.nima.2013.06.061