Anomalous enhancements of low-energy fusion rates in plasmas: the role of ion momentum distributions and inhomogeneous screening

✍ Scribed by Coraddu, Massimo ;Lissia, Marcello ;Quarati, Piero

• Book ID: 111489104
• Publisher: Walter de Gruyter GmbH
• Year: 2009
• Tongue: English
• Weight: 647 KB
• Volume: 7
• Category: Article
• ISSN: 2391-5471
• DOI: 10.2478/s11534-009-0068-y

✦ Synopsis

Non-resonant fusion cross-sections significantly higher than corresponding theoretical predictions are observed in low-energy experiments with deuterated matrix target. Models based on thermal effects, electron screening, or quantum-effect dispersion relations have been proposed to explain these anomalous results: none of them appears to satisfactory reproduce the experiments. Velocity distributions are fundamental for the reaction rates and deviations from the Maxwellian limit could play a central role in explaining the enhancement. We examine two effects: an increase of the tail of the target Deuteron momentum distribution due to the Galitskii-Yakimets quantum uncertainty effect, which broadens the energy-momentum relation; and spatial fluctuations of the Debye-Hückel radius leading to an effective increase of electron screening. Either effect leads to larger reaction rates especially large at energies below a few keV, reducing the discrepancy between observations and theoretical expectations.