ALPHA-PARTICLE INDUCED LUMINESCENCE IN ARGON IN AN ELECTRIC FIELD

The fluorescence emission from purified argon at atmospheric pressure has been analysed spectrophotometrically by the use of calibrated optical filters. Over 90% of the total emission has been found to be contained within the continuum centred at 1250 Angstrom. By examining the effect of an applied electric field on the continuum centred at 2250 Angstrom the origin of this emission is suggested as being above the lower energy limit for dimeric ion formation at 14·7 ev. No evidence has been found for the presence of columnar dissociative recombination along the alpha-particle track.