Optimal Laser Wavelength for Resonant Transmission through the Coulomb Barrier

The 1993 point-particle, 1-D semi-classical quantum-mechanical theory of resonant transparency of the Coulomb barrier [1], though admittedly crude, has some plausibility as to relevance and adequacy because it predicts quantitatively different results for lattices of protons versus deuterons embedded in host lattices of palladium versus nickel. Specifically it predicts that cold fusion is likely with Ni cathodes and electrolysis with either ordinary or heavy water, whereas it is likely only for heavy-water electrolysis with Pd cathodes. The question of whether or not this 1993 theory has any predictive power regarding the 2003 Letts-Cravens effect is considered and answered as: “partially.” That is, the “optimal” range of wavelengths includes that discovered by Letts and Cravens, but because of the possibility of multi-photon reactions it does not uniquely single out their 680 nm as best, which would require a more detailed model (including e.g. cathode temperature) than provided by the simplified 1993 theory.