Enhancement of cold fusion rate by electron polarization in palladium deuterium solid

We present results of a qualitative theoretical study of the problem of the enhancement of deuterium-deuterium fusion tunneling rate in palladium deuterium (Pd-D) solids. We first show, based a WKB argument, that the cold fusion rate is dominated by the form of the Coulomb potential on a length scale at and slightly below that of the solid state physics. We then use a qualitative random phase approximation (RPA) theory to show that because the Pd-Dx system for x ≈ 0.5 is approximately a semiconductor system, the associated large dielectric constant at large length scales significantly reduces the tunneling repression exponent λ between the deuterium ions, leading to an enhanced tunneling rate for the D-D nuclear fusion reaction inside the Pd host at room temperature, to an order λ ∼ 10−40 S−1, over the corresponding rate in a vacuum, λ ∼ 10−70 S−1, when one uses the most optimistic way of estimating the tunneling exponent. This level of enhancement for the fusion rates is, however, still too low to explain the claims of the recent experiments on cold fusion.