Cold fusion is not impossible quantum mechanically, but it may be improbable. Given enough deuterium atoms in sites where two or more deuterium nuclei are closely trapped together, overcoming part of the Coulomb potential barrier, quantum tunneling transforming deuterium into helium must eventually occur. What is needed for a theoretical calculation is the height of the Coulomb potential barrier in vacuum, and an estimate of the internuclear distance and of the reduction of the Coulomb potential barrier height in the catalytic medium used in Prof. Arata' s repetition of F.and P.'s experiment, to produce a sufficient amount of fusion by quantum tunneling ,within 50 hours.
