ISSN:
1573-7357
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract Decay mechanism of H 2 - anions in X(γ)-irradiated solid para-H2 (p-H 2 ) has been studied using high-resolution ESR spectroscopy in the temperature range between 1.3–6.6 K. The results are summarized as follows. First,the decay rate constant of the 2 - anions is not proportional to initial yields of reactive species such as cations and H atoms but proportional to the concentration of less-reactive species of HD molecules in p-H2 . This result shows that the decay of the 2 - anion is due to the reaction neither with cations nor H atoms but with HD molecules originally contained in the p-H2 sample at natural abundance. Second,the decay rate constant of the 2 - anions increases proportionally with the increase in temperature below 3 K and decreases with the increase in temperature between 3–5 K,although it increases exponentially with the increase in temperature above 5 K. This result indicates that the decay rate constant of the 2 - anions is controlled by the rate constant for the diffusion of the 2 - anions via one-phonon assisted quantum tunneling below 3 K,two-phonon scattered or assisted quantum tunneling between 3–5 K,and thermally-activated process above 5 K.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1021850103903
