Field effects on ionic and excitonic quenching for heavy ions in liquid Ar

An increase in scintillation of up to 17% has been observed in liquid argon with the application of low electric fields (<6 kV/cm) for /sup 1/H, /sup 4/He, /sup 18/O and /sup 36/Ar ions of energy 1-35 MeV/u. This increase occurs at a field much lower than that required for the proportional region (10/sup 6/ V/cm). The observed phenomenon is attributed to the recovery of quenching in the high excitation density region of the particle track by the external field.