Electron spin effects in superconducting Al films have been studied by measuring the conductance of tunnel junctions in a magnetic field. Superconductor-normal-metal tunnel junctions were made with 50-A-thick Al and 500-1000-A-thick Ag films with A1203 as the barrier. The measured conductance curves were fit by theoretical calculations, which included depairing effects and spin-orbit scattering, and values of the depairing parameter $0 and the spin-orbit parameter bo were obtained. The relation $0 -f(0) + C@~j &0 was found to describe the (parallel) magnetic field dependence of the depairing.The values of bo obtained were independent of H. Superconductor-superconductor tunnel junctions made with two SO-A-thick Al films were studied with various amounts of Ge and Mn impurities. The Ge impurity simply raised T"whereas the Mn lowered T, and increased bo. The approximate dependence of bo on the Mn impurity concentration was obtained. The qualitative features for spin-orbit scattering predicted by theory were observed, and spin-flip scattering in the tunneling process was shown to be negligible.

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Where it is not feasible to reduce radon levels in houses, exposure to radon decay products may still be reduced through air filtration or other air treatment techniques. A model which accurately describes the behavior of decay products indoors would be helpful to development or improvement of such air treatment techniques. We use a minor modification of a well-known model to describe the behavior and fate of radon decay products in the average indoor environment, and examine the adequacy of the model to predict the impact of a variety of air treatment techniques on indoor radon decay product levels. We find that the indoor environment is successfully described by the model and that plate-out of radon decay products on surfaces is much less than previous work has suggested. We also find that the model provides a plausible explanation of the effectiveness of a variety of techniques that remove radon decay products from the air.

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