Low-energy nuclear reactions boosted by collisions with environment (Carambole collisions)

Abstract

In conventional nuclear experiments a beam of accelerated nuclei collides with a target nucleus that is surrounded by other nuclei in a molecule, in condensed matter, or in a plasma environment. It is shown that for low collision energies possible nuclear reactions (including deuterium fusion) are strongly boosted by the environment. The gain is due to the transfer of centre-of-mass energy into energy of relative motion. The effect originates from a chain of preliminary three elastic collisions which transform the projectile-target experiment into one with colliding beams. Firstly, the projectile-target pair of nuclei undergo elastic scattering in which the projectile shares its energy and momentum with the target nucleus. Then the projectile and target nuclei collide with different heavy nuclei from the environment. These latter collisions change the velocities of the target and projectile nuclei and set them again on the collision course. Finally, the same pair of nuclei collide inelastically, this time giving rise to the nuclear reaction. The increased energy of the target nucleus increases the relative velocity up to √2 times, resulting in a drastic exponential increase of the probability to penetrate the Coulomb barrier and thereby sharply increasing the likelihood of the nuclear reaction. Applications to laser-induced fusion are discussed.