Numerical modelling of the quantum-tail effect on fusion rates at low energy

Abstract

Results of numerical simulations of fusion rate d(d,p)t, for low-energy deuteron beam, colliding with deuterated metallic matrix (Raiola [1,2]) confirm analytical estimates given in Ref.[3] (M. Coraddu et al., this issue), taking into account quantum tails in the momentum distribution function of target particles, and predict an enhanced astrophysical factor in the 1 keV region in qualitative agreement with experiments.

Fusion reactions in plasmas as probe of the high-momentum tail of particle distributions

“…Following the analysis of the previous section, target particles have a Boltzmann-Gibbs energy distribution with a relation between energy and momentum that is broadened by plasma quantum effects and it is given by Eq. (7). The effective momentum distribution of the target particles is, therefore, not Maxwellian but given by Eq.…”

Modified Debye‐Huckel Electron Shielding and Penetration Factor

“…In deuterated metals or solid-state matter, the effect of strong screening has yet to be clearly understood and discussed, although a few interesting descriptions have recently been brought forward to reproduce experimental results (Raiola et al 2004;Coraddu et al 2004aCoraddu et al , 2004bCoraddu et al , 2006Kim & Zubarev 2006). The approach we are referring to here is very useful in understanding the fusion rates in this matter, which could simulate some high-density astrophysical plasmas.…”

Theoretical Interpretation of Anomalous Enhancement of Nuclear Reaction Rates Observed at Low Energies with Metal Targets

“…Furthermore, the classical plasma theory of Debye is valid only if there are enough particles (electrons) in the cloud, N D ) 1, where N D ¼ ð4=3Þn 0 R D 3 . For the above case, N D % 3 Â 10 À5 , and hence the Debye theory may not be applicable for this case as pointed out by Coraddu et al 19) More recently Coraddu et al [19][20][21] used a modified momentum distribution introduced by Galitskii and Yaki-mets, 22) in an attempt to explain the anomalies. As shown by Galitskii and Yakimets (GY) 22) the quantum energy indeterminacy due to interactions between particles in a plasma leads to a generalized momentum distribution which has a high-energy momentum distribution tail diminishing as an inverse eighth power of the momentum, instead of the conventional Maxwell-Boltzmann distribution tail which decays exponentially.…”

“…As shown by Galitskii and Yakimets (GY) 22) the quantum energy indeterminacy due to interactions between particles in a plasma leads to a generalized momentum distribution which has a high-energy momentum distribution tail diminishing as an inverse eighth power of the momentum, instead of the conventional Maxwell-Boltzmann distribution tail which decays exponentially. GY's generalized momentum distribution has been used by Coraddu et al [19][20][21] for deuterons in a metal target in an analysis of anomalous cross-sections for D(d,p) 3 H observed from the low-energy deuteron beam experiments. 8,9,11) Their calculated results for the fusion rates between the beam deuteron and quasi-free mobile deuteron in a metal target are too small to explain the observed experimental anomalies.…”