Historical research guide · 0016 · 2017
Experimental Observations of Nuclear Activity in Deuterated Materials Subjected to a Low-Energy Photon Beam
Steinetz, Bruce M. · Benyo, Theresa L. · Pines, Vladimir · Pines, Marianna · Forsley, Lawrence P. · Westmeyer, Paul A. · Chait, Arnon · Becks, Michael D.
In one minute
In 2015 a NASA Glenn team led by Bruce Steinetz loaded erbium and hafnium metal with deuterium — the heavy form of hydrogen — mixed each metal with deuterated wax and a pinch of ordinary molybdenum powder, and stood the vials in front of an industrial linear accelerator producing photons of about 2 million electron-volts. That beam is deliberately gentle: below the 2.226 MeV needed to break a deuterium nucleus apart, so on the textbook account nothing nuclear should happen. Every deuterium-loaded sample came out radioactive, carrying fresh isotopes of erbium, hafnium, molybdenum and technetium, and the detectors logged neutrons from thermal energies up to more than 10 MeV. Matching samples loaded with ordinary hydrogen, and bare metal with no gas at all, showed nothing above background. Steinetz and colleagues walk through photodissociation, electron capture and photoneutron production, rule each one out, and say plainly that the mechanism is still open. These runs became NASA Glenn's lattice confinement fusion programme, published in Physical Review C in 2020.
Connection
This is the bench record behind chapter 12: pack a metal lattice with deuterium and the barrier to nuclear reactions drops so far that a two-million-volt photon beam is enough to start them. It is the thesis's first door — fusion as a screening problem rather than a confinement problem — written down as measurements, controls and serial numbers.
From the source
Deuterated erbium and hafnium exposed to a nominal 2 MeV photon beam produced new radioisotopes — erbium-163, erbium-171, hafnium-180m and hafnium-181 — and the team reports the technique created new isotopes with 100 percent reproducibility across the fuelled shots.Section 3.1.1; Tables IV and V
The molybdenum witness powder, which was never gas-loaded, came back activated as molybdenum-99 and molybdenum-101 with their technetium daughters, so the nuclear activity reached beyond the deuterated metal into a neighbouring material.Section 3.1.1; Table IV(b)
Control samples loaded with ordinary hydrogen, and bare metal with no gas loading at all, run in the same beam at the same distance for the same time, produced no new gamma lines, no beta activity above background and no bubble-detector counts above background.Sections 3.1.2, 3.2.1 and 3.3.1; Tables VIII and IX
CR-39 track detectors recorded fast neutrons between 1.4 and 2.5 MeV, plus triple tracks indicating neutrons of 10 MeV or more, while the beam end-point energy was measured at 1.95 MeV — below the 2.226 MeV threshold at which a photon can split a deuteron.Section 3.3.3; Figures 7 to 9
Seven candidate explanations — photodissociation, electron capture, photoneutron reactions, gamma-metastable excitation, the Mossbauer effect, three-body interactions and outside contamination — are each examined and excluded, and the authors state that the mechanism causing the nuclear activity remains to be determined.Section 4.2
The named next measurement is a repeat of the experiment at a facility that can certify the beam end-point energy to five sigma or better, below the deuteron photodissociation threshold.Section 4.3
The way in
https://ntrs.nasa.gov/citations/20170002584How to cite it
Steinetz, Bruce M., Benyo, Theresa L., Pines, Vladimir, Pines, Marianna, Forsley, Lawrence P., Westmeyer, Paul A., Chait, Arnon, Becks, Michael D. (2017) Experimental Observations of Nuclear Activity in Deuterated Materials Subjected to a Low-Energy Photon Beam https://ntrs.nasa.gov/citations/20170002584