Historical research guide · 0442 · 2024
Electrochemically-enhanced nuclear fusion of deuterium
Kuo-Yi Chen · Phil A. Schauer · Sergey Issinski · Fatima H. Garcia · Ryan Oldford · Luca Egoriti · Shota Higashino · Jannis Maiwald · Aref E. Vakili · Yunzhou Wen · Joseph Koh · Thomas Schenkel · Monika Stolar · Amanda K. Brown · Curtis P. Berlinguette
In one minute
Curtis Berlinguette’s group at the University of British Columbia built a fusion reactor small enough to sit on a laboratory bench, then used it to ask a question chemists are not supposed to ask: can a chemical reaction running at a few electron-volts change the rate of a nuclear reaction running at millions of electron-volts? Their Thunderbird Reactor pulls deuterium ions out of a microwave plasma and drives them at 30 kilovolts into a thin palladium foil, where they fuse with deuterium already lodged in the metal; the neutrons that come out are counted as the tally of fusion events. On the far face of that same foil sits an electrochemical cell that pumps still more deuterium into the palladium from heavy water. Switching the cell on raised the fusion rate by 15 percent, repeated across three campaigns with three fresh targets. The reactor’s power output is tiny and the authors say so plainly. The result is the point: an electrochemical dial that reaches the nucleus.
Connection
Chapter 12’s argument is that a metal lattice is a fusion environment in its own right — fuel packed at solid density, with the lattice itself changing the odds — and this is the cleanest published demonstration that a chemical-scale knob moves a nuclear rate. It is also the site’s model of how such a result should be reported: a stated mechanism, three repeats, and the power figure given honestly rather than dressed up.
From the source
A solid metal lattice holds deuterium fuel at a density of about 10²⁸ per cubic metre, which is eight orders of magnitude denser than the roughly 10²⁰ per cubic metre of magnetic confinement, and only three orders below the roughly 10³¹ per cubic metre of inertial confinement — a density inertial confinement holds for only hundreds of picoseconds, while the lattice holds it indefinitely.Main, opening section (Supplementary Note 1)
Deuterium ions accelerated into a palladium target by plasma immersion ion implantation produce deuterium-deuterium fusion inside the metal: the neutron rate climbs from a laboratory background of 0.2 per second to a stable 130 to 140 per second within about thirty minutes at minus 30 kilovolts, and the rising-then-saturating shape of that curve is what fusion inside the lattice looks like rather than fusion in the gas or plasma. The authors record this as the first demonstration of fusion driven this way.Nuclear fusion, by plasma immersion ion implantation; Fig. 3
Turning on the adjacent electrochemical cell, while the ion beam keeps running, raises the fusion rate by an average of 15(2) percent — 133.1(5), 140.3(5) and 136.0(3) neutrons per second for three separate targets, individual increases of 15.1, 11.3 and 18.5 percent.Electrochemically-enhanced fusion; Fig. 3 caption
In situ X-ray diffraction confirms what the electricity is doing to the metal: the electrochemical current loads the palladium to a deuterium-to-palladium molar ratio of 0.7, and that deuterium stays in the lattice under ambient conditions and under vacuum on the timescale of the experiment — which is why switching the cell off leaves the neutron rate within 2 percent of its peak.Electrochemically-enhanced fusion (Supplementary Figs. 9 to 14)
An electrochemical reaction at the electron-volt energy scale can measurably increase a nuclear reaction rate at the mega-electron-volt energy scale — the two scales are coupled through the fuel density the chemistry sets inside the target.Abstract; closing paragraph of the Main text
The reactor’s neutron yield is equivalent to about 10⁻⁹ watts for 15 watts of input power, and the authors name the routes to raise it: an inductively coupled plasma held at higher pressure to put more ions on the target, metals that load more deuterium such as niobium and titanium, secondary fusion with the helium-3 and tritium the reaction itself makes, and quantum coherence effects in the target under coherent stimuli. The same bench can probe screening effects and intranuclear resonances below 5 keV.Closing paragraph of the Main text (Supplementary Note 7)
The way in
https://doi.org/10.21203/rs.3.rs-5046357/v1How to cite it
Kuo-Yi Chen, Phil A. Schauer, Sergey Issinski, Fatima H. Garcia, Ryan Oldford, Luca Egoriti, Shota Higashino, Jannis Maiwald, Aref E. Vakili, Yunzhou Wen, Joseph Koh, Thomas Schenkel, Monika Stolar, Amanda K. Brown, Curtis P. Berlinguette (2024) Electrochemically-enhanced nuclear fusion of deuterium doi:10.21203/rs.3.rs-5046357/v1