Experimental study of ionization yield of liquid xenon for electron recoils in the energy range 2.8–80 keV

We present the results of the first detailed experimental study of ionization yield of electron recoils with energies below 100 keV produced in liquid xenon by the isotopes 37Ar, 83mKr, 241Am, 129Xe, 131Xe. It is confirmed by a direct measurement with 37Ar isotope (2.82 keV) that the ionization yield increases with the energy decrease in the energy range below ~ 10 keV in accord with the NEST predictions. Decay time of scintillation at 2.82 keV is measured to be τ = 25 ± 3 ns at electric field 3.75 kV/cm.