Nucleosynthesis, Age of the Universe, and Nuclear Astrophysics 7.Screening Effects in Low Energy Nuclear Reactions in Laboratories
Abstract
Nuclear reactions in stars are known to be affected by the surrounding plasma. The reaction rates between various light nuclei measured in recent laboratory experiments show an increasing enhancement with decreasing collision energy compared with the extrapolation from higher energies. This phenomenon has been analysed in terms of the screening effects by bound target electrons. Surprisingly in all systems experimentally studied so far the extracted screening energy is significantly larger than the value in the adiabatic limit, which is expected to be the maximum value. Comparison with the recent indirect mothod named the Trojan Horse method also suggests a large screening effect to exist in direct measurements. We review the present status of the theoretical and experimental studies of this problem, and touch a recent study which has pointed out the importance of the explicit treatment of the behaviour of electrons in the tunneling region based on a semiclassical mean field theory of quantum tunneling.
- Publication:
-
Journal of Plasma and Fusion Research
- Pub Date:
- 2003
- DOI:
- 10.1585/jspf.79.891
- Bibcode:
- 2003JPFR...79..891T
- Keywords:
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- screening effect;
- bound electron;
- low energy nuclear reaction;
- laboratory experiment;
- dynamical effect;
- influence of tunneling;
- screening energy;
- adiabatic limit