Scintillation from Charged Particles in Liquid Helium

Studies of scintillation in liquid helium resulting from the passage of charged particles is of both practical and theoretical interests. Recently, a diverse range of experiments including the search for the neutron electric dipole moment (nEDM), the measurement of the neutron-decay lifetime, solar neutrino detection, and the search for dark matter have used or proposed the use of liquid helium scintillators. With such broad applications, many properties of the scintillation remain to be explored. I will discuss the ongoing R&D effort at Los Alamos National Laboratory to measure scintillation from liquid helium under conditions pertinent to the proposed nEDM experiment at the Spallation Neutron Source (SNS). Important to this effort is an understanding of the dependence of the scintillation light produced by different particles (alphas, electrons, protons, tritons) when the liquid is subjected to high electric fields (10’s of kV/cm) over a wide range of temperatures (0.5 K – 4K) and pressures.