LASER-ENHANCED PROPORTIONAL GAS SCINTILLATIONS

It is shown that laser excitation can be used to amplify the proportional atomic scintillations in Ne, Ar and Kr. In a special chamber the laser light tuned to the lowest s-p transitions is introduced through the anode by an optical fibre and the effect on the proportional scintillation yield is studied at wavelengths longer than that of the laser. An increase in the scintillation yield is observed for a majority of the laser-excited transitions. The 3p-state with j = 3 in Ne, which have only one decay channel to the 3s-states, gives a yield amplification of 10. The detected signal is entirely due to collisional transfer of this state to other p-states that decay radiatively. In argon many transitions show amplifications above 5 as obtained with a laser power of typically 100 mW.