Improved detection of ultraviolet radiation with gas-filled phototubes through photoionization of excited atoms

Using dc biases higher than those recommended by manufacturers, it is possible to exploit photoionization of excited atoms to obtain high sensitivities to uv radiation using gas-filled phototubes. Spectral response, nonlinearity of response, and dc bias effects are discussed. Comparisons are made with uv semiconductor detectors, and suggestions for future research are made. If a photocathode is used in a gas tube such devices are quite sensitive to both visible and uv radiation.