Decay processes of H2
- anions in
γ-ray-irradiated solid parahydrogen were studied by using an
ESR
spectrometer. The following interesting results were obtained.
First, the initial yields of ortho-H2
-
anions in
the γ-irradiated solid parahydrogen were 3 times as large as those of
para-H2
- anions. Second, the yields
of
para-H2
- anions decrease faster than those of
ortho-H2
- anions upon storage of the
irradiated samples at 4.2
K. Third, the decay rate of H2
- anions
is accelerated by the addition of HD and D2 molecules.
Fourth, H2
-
anions at 2.2 K decay faster than at 4.2 K. According to the
parity conservation rule in a homonuclear
diatomic molecule, the energy of ortho-H2
-
anions at the ground state is lower than that of
para-H2
- anions,
whereas that of ortho-H2 molecules is higher than that of
para-H2 molecules at low temperatures. The
first
and second results are ascribed to para → ortho conversion of
H2
- anions. The third result indicates
that
nearby HD and D2 accelerate the decay of
H2
- anion or broaden the spectra by
superhyperfine interactions.
The fourth result suggests a coherent tunneling mechanism of decay
of H2
- anions in the solid
parahydrogen.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.