Changes of ESR parameters of trapped hydrogen atoms in sulfuric acid glasses stored at 77 K

The ESR parameters of trapped hydrogen atoms in 6 M sulfuric acid glasses stored at 77 K change with time, achieving the apparent equilibrium values, A = 1411.1 MHz and g = 2.0020, 250 h after γ-irradiation. Immediately after γ-irradiation the hyperfine splitting constant is significantly higher, A = 1412.5 to 1412.9 MHz. The observed increase of A shift from the free atom value, 1420.4 MHz, provides a direct evidence of the increasing interaction with the matrix making hydrogen atoms less reactive during the storage. (author)