NASA returns to LENR as a fuel of the future or as they call it “lattice confinement” referring to the lattice structure formed by the atoms making up a piece of solid metal. The NASA group used samples of erbium and titanium for their experiments. Under high pressure, a sample was “loaded” with deuterium gas, an isotope of hydrogen with one proton and one neutron. The metal confines the deuterium nuclei, called deuterons, and excess energy is released via a fusion process.
More can be read here: https://spectrum.ieee.org/energywise/energy/nuclear/nuclear-fusiontokamak-not-included
Below is an informative interview from Tech Talks Daily Podcast which interviews Laurence Forsley, senior experimental physicist with NASA, research fellow at the University of Texas, and CTO of Global Energy Corporation