Study of the stabilization and recombination of nitrogen atoms in impurity-helium condensates

The stabilization and recombination of nitrogen atoms N(S-4) in nitrogen-helium and nitrogen-neon-helium condensates obtained by the injection of impurity particles from a gas discharge into bulk superfluid helium are investigated by the EPR method. It is established that the stabilized nitrogen atoms reside inside and on the surface of impurity clusters forming a porous structure in the bulk superfluid helium. The possibility of increasing the specific energy of impurity-helium condensates by increasing their density through mechanical pressing is investigated. For nitrogen-helium condensates an eightfold increase in the specific energy is achieved. The recombination loss of N(S-4) upon heating of impurity-helium condensates in the temperature range 1.7-7 K is detected. This permits verification of the mechanism of thermoluminescence of impurity-helium condensates. (C) 2005 American Institute of Physics.