Observation of UV enhanced fluorescence due to the combined effects of selective optical pumping and collisional transfer

We have recently reported [1] enhanced UV fluorescence at 2138 Å due to selective optical pumping with 560 Å EUV line radiation. In this paper, measurements are described of the collisional transfer of the population from the optically pumped level to a higher angular momentum level. Enhanced fluorescence at 2993 Å from this higher level was measured. These measurements are discussed in light of proposed soft X-ray laser schemes using such a pumping process.