Scintillation and ionization yield forαparticles and fission fragments in liquid argon

The scintillation and ionization yields in liquid argon by {α} particles and fission fragments have been measured as a function of the applied electric field ({≤}38 kV/cm). The quenching due to high excitation density does not depend on the field for {}4 kV/cm for {α} particles. The scintillation due to {α} particles shows a maximum at about 1.5 kV/cm. This increase (2.5±{}0.7%) of the scintillation at low fields has not been observed heretofore and is ascribed to the presence of a quenching process at zero field.