Pines et al patent.
Their writing looks like some of the LENR explanations that have been written before to explain how low energy inputs overcome the Mev Coulomb barrier.
They neglect to say what causes the screening
" For example, some embodiments of the present invention may fuse light elements to a target material or each other by exposing the target material to energetic electrons in an environment containing a suitable high density nuclear fuel, such as deuterium or tritium, as a high pressure gas or in liquid or solid forms, optionally as a compound with other elements. In certain embodiments, in addition to or in lieu of the fuel, the target itself, whether solid or liquid, may contain deuterium or tritium (e.g., a “deuterated” or “tritated” target). This exposure to energetic electrons causes deeply screened tunneling and/or converts at least a portion of the metal-dissolved fuel into neutral nuclei. In the case defined as “deeply screened tunneling,” an energetic electron or electrons that possess specific individual or collective quantum properties may pass sufficiently close to a nucleus of a deuterium or tritium atom such that the electrostatic repulsion between the screened nucleus and any adjacent nucleus is not felt by the adjacent nuclei outside the much reduced screening radius for a brief period of time. This significantly increases the quantum tunneling reaction probability between the nuclei even at lower kinetic energies."