Can solid-state effects enhance the cold-fusion rate?

Abstract

RECENTLY two groups^1,2 have reported finding experimental evidence for an unexpectedly high rate of nuclear fusion at room temperature during the process of electrolytic deposition of deuterium on palladium^1,2 and titanium². To achieve the rate of neutron production (∼10⁻²³s⁻¹ per deuteron pair) cited in ref. 2 (and a fortiori, that inferred in ref. 1) requires the solid-state environment to produce either an unusual enhancement of the fusion reaction rate or a large suppression of the Coulomb barrier between deuterons. The latter would presumably arise from some kind of sophisticated many-body screening effect in Pd or Ti, perhaps associated with quasiparticles of large effective mass². Here we point out that within the framework of the lowest-order Born-Oppenheimer approximation, a very severe constraint is imposed on all such screening mechanisms in solids in equilibrium by the observable binding affinity of ⁴He atoms for the metal in question. Unless the latter is quite anomalous, the Coulomb barrier penetration in a solid in equilibrium cannot be enhanced anywhere near the magnitude required to explain the fusion rates inferred from the experiments.