Historical research guide · 0523 · 2024
Advancements in the Production of Anomalous Heat Effect in Constantan Wires: Developing a Robust Experimental Protocol
Francesco Celani · C. Lorenzetti · G. Vassallo · E. Purchi · S. Fiorilla · S. Cupellini · M. Nakamura · P. Cerreoni · R. Burri · P. Boccanera · A. Spallone · E. F. Marano
In one minute
Francesco Celani’s group at Italy’s Frascati national laboratory has been chasing anomalous heat since 2011 in the cheapest wire they can buy: Constantan, a copper-nickel-manganese alloy, drawn to 200 micrometres, oxidised in air until its surface is a sub-micrometric sponge, then painted with strontium, iron, potassium and manganese salts that bake down to oxides. This paper is their attempt to write the activation recipe down so other laboratories can follow it. The wire coils around an iron tube inside a thick borosilicate reactor, heated by its own current in hydrogen or deuterium, with helium runs as the reference. What they report is that the recipe is mostly patience: plain direct-current heating for 50 to 150 hours activates a virgin coil, the heat effect grows with every conditioning cycle, and it leaves a positive memory that lasts 10 to 20 hours. And for the first time in fourteen years of these experiments, deuterium beat hydrogen — better than 9 watts against 5 at the same input.
Connection
Chapter 12 wants the conditions that make a metal lattice a place where tunnelling matters, and this paper is about nothing else: not a new material but a written-down activation procedure, with the control knobs named — time at high power, voltage gradient along the wire, resistance ratio, number of cycles. It earns chapter 1 for the honesty of its bookkeeping, including the awkward finding that even the helium calibration run is not a true blank because hydrogen from the coating comes back out of the bulk above 120 watts. The same group’s later reactor, which adds a transverse plasma discharge and reaches a coefficient of performance near 1.27, is on the site at /library/stm-458152e275, and Michael Staker’s superabundant-vacancy picture runs through both.
From the source
A straightforward procedure of high-power direct-current Joule heating sustained for 50 to 150 hours activates virgin Constantan coils, provided the thin wire surfaces have been treated, mainly with low work function materials — the pulsed high-peak-power route the group used earlier is more efficient but has proved hard for other laboratories to reproduce.Abstract, Key Findings; Section 4, Procedures of Reactor Preparation at INFN-LNF
The material and geometry are fully specified: Ni44-Cu55-Mn1 Constantan wire of 200 micrometre diameter and about 158 to 160 centimetres length weighing 0.45 grams, coiled in roughly 50 to 75 turns around an inner 5 millimetre iron counter-electrode inside a 3.2 millimetre-walled borosilicate reactor, with the outer wall wrapped in aluminium foil painted with a black compound of emissivity greater than 90 percent, reaching 900 degrees Celsius internally and 380 externally at more than 150 watts input.Sections 2 and 3, Experimental Set-Up and Reactor Design; Figures 2 to 4
Activation accumulates. Across cycles H2 number 1 to H2 number 4 the anomalous heat rose steadily while the normalised resistance ratio fell, the same qualitative pairing seen with palladium since 1990, so the dominant control is the time the wire spends at high power under a large voltage gradient rather than the gas pressure — and the effect also grows with the number of cycles between high and low power and leaves a positive memory lasting 10 to 20 hours.Section 5, First type of Experiments: Increasing Activation; Figure 5
The activated state can be spoiled and only partly recovered: 15 hours of dynamic vacuum at 730 degrees Celsius followed by fresh hydrogen gave a lower heat effect in cycle H2 number 5 than in H2 number 4, most visibly at high power, and a further 113 hours of conditioning at 152 watts in cycle H2 number 6 reduced it further rather than restoring it.Section 6, Second Type of Experiment: Effect of Vacuum Degassing and Refilling Cycles; Figure 6
An isotopic effect appeared for the first time in this campaign, run from 21 December 2021 to 10 March 2022: after twelve activation cycles, deuterium gave more than 9 watts of anomalous heat against 5 watts under hydrogen at the same 130 watt input, with a peak specific value near 20 watts per gram of Constantan at wire temperatures of 500 to 600 degrees Celsius. In earlier years the comparison had gone the other way or given nothing, and the authors note the deuterium runs followed the hydrogen runs, so a positive aging effect is not excluded.Section 7, First Type of Experiment: Isotopic Effect; Figure 7
Two things are stated as unfinished. The calibration is not as clean as it looks — even the first helium cycle is not a true blank, because hydrogen taken up from the coating solution during pre-conditioning at about 900 degrees Celsius comes back out of the bulk once applied power exceeds 120 watts. And the whole procedure still costs weeks of high-power operation, so the group’s named next step is an energy-efficient reactor in which high peak power pulses supply the gas flux for far less external input.Section 4, on the helium blank; Section 9, Conclusions and Future Plans
The way in
https://doi.org/10.70923/001c.124958How to cite it
Francesco Celani, C. Lorenzetti, G. Vassallo, E. Purchi, S. Fiorilla, S. Cupellini, M. Nakamura, P. Cerreoni, R. Burri, P. Boccanera, A. Spallone, E. F. Marano (2024) Advancements in the Production of Anomalous Heat Effect in Constantan Wires: Developing a Robust Experimental Protocol doi:10.70923/001c.124958