The lattice ladder
University. · 2 min read
What it proposes
Treat the Coulomb barrier as an environmental quantity rather than a constant. Pack deuterium into a metal so densely that the metal's own electrons partly cancel the charge between nuclei, then supply a small trigger. The barrier does not vanish; the reaction rate at a given energy climbs, by a factor that depends only on which solid the nuclei are sitting in. That single sentence is the most institutionally solid claim in this whole programme, and it is the rung every energy page should route through.
Who it is forMaterials engineers · Nuclear physicists
Why the library suggests it
Walk the rungs the Glenn team actually ran — load the metal, screen the charge, trigger the beam, read the neutrons — one step at a time.
Before you move anything — what do you expect?
Optional, and there is no score. The instrument below works exactly the same whether you answer or not.
The Glenn run, one step at a time
This is the experiment behind the two Physical Review C papers, in the order it actually happens. Load a metal with deuterium until the nuclei sit in the gaps of the crystal. Let the metal's own electrons screen the charge between them. Trigger it with a photon beam. Then read the neutrons that come back out of fuel which never moved. Walk the five steps and watch the chain close.
Apparatus in the paper
Deuterium is packed into titanium or erbium until the nuclei sit in the gaps of the crystal itself, at solid-state density and at room temperature. There is no plasma here and no magnet: the metal atoms hold the fuel where they are.
What this step carries
- Deuterium held in the lattice
- 1E22–1E23 per cubic centimetre
What these papers report is reactions, and the energy went in as gamma rays. Net energy gain is a different measurement and it has not been made. A reactor that returns more than it draws would be burning fuel, which is a separate sentence and a separate milestone.
Scope: this instrument draws the published chain of the 2020 campaign and the energies attached to it. It computes no cross-section, no heat and no power output.
Every number on this instrument comes from these source sheets
- Steinetz, Benyo, Chait and colleagues 2020: novel nuclear reactions in bremsstrahlung-irradiated deuterated metals
- Pines, Steinetz, Forsley and colleagues 2020: the screening theory published alongside it
- NASA Glenn 2020: the lattice confinement fusion programme overview and its review panel
- The measured screening energies, host by host
The NASA Glenn team loaded erbium and titanium with deuterium, hit the samples with a bremsstrahlung beam of no more than 2.9 million electronvolts, and measured 2.45 MeV neutrons — the fingerprint of deuterium-deuterium fusion — repeatably, from fuel that never moves (Novel nuclear reactions in bremsstrahlung-irradiated deuterated metals, 2020). The programme around that measurement, including the four-panellist review whose job was to attack it, is set out in Lattice Confinement Fusion Overview (2020) and in plain language for engineers in A New Way of Triggering Nuclear Fusion (2022), which gives the loading figure that makes it work: about ten to the twenty-third deuterons per cubic centimetre, nine orders of magnitude denser than a magnetically confined plasma. The size of the screening effect is not a model, it is measured on an accelerator: in titanium the screening energy is about 27 electronvolts, in palladium about 310, in palladium oxide about 600 — and at a bombarding energy of 2.5 kiloelectronvolts, palladium oxide fuses about a hundred times more often than the bare-nucleus rate (Screening energy for low energy nuclear reactions in condensed matter, 2020). The NASA and Navy account of the mechanism, matched against a measured shift in beryllium-7's half-life when caged inside a buckyball, is Electron Screened and Enhanced Nuclear Reactions (2022).
The experiment or build
The next rung is not a bigger machine, it is a materials series. Kasagi's screening energies were measured on a handful of hosts. Nobody has run the full sweep: load twenty different hosts and host chemistries — metals, oxides, alloys, nanostructured films — to a measured stoichiometry, fire the same low-energy deuteron beam at each, and publish the screening energy against the material. The settling measurement is screening energy in electronvolts, per host, with the loading ratio measured independently, plotted so that a materials engineer can read off which solid to build a reactor from. That plot does not exist and it is the single most useful missing document in the field.
Research context
The effect is in two Physical Review C papers with NASA authorship, reviewed by a panel convened to challenge it, and the materials survey behind it is thin.
Take it up
- The measurement that settles it
- The settling measurement is screening energy in electronvolts, per host, with the loading ratio measured independently, plotted so that a materials engineer can read off which solid to build a reactor from.
- What it costs to start
- University.
- The engineer it grows
- This is the card that makes the point the thesis keeps making: the bottleneck is materials science, not theory.
What it rests on
Where it sits in the curriculum