Publication Type: Peer-Reviewed Journal Article
Research Type: Experimental
Solid State Fusion Type: LENR/Cold Fusion
Reactor Set-Up: Vacuum Chamber
Observables: Excess Heat (power and/or energy), Morphological Features of Interest
Stimulation: Gas Loaded
Material: Nickel, Copper, Calcium oxide, Nanomaterial
Isotopic Hydrogen Reactants: H2
Summary: "Iwamura and colleagues report on anomalous heat generation from layered nickel and copper thin film nanocomposite samples loaded with hydrogen gas. Two samples were positioned in a vacuum chamber and stimulated by a ceramic heater, where the power delivered to the heater was recorded and the local temperature was measured by a thermocouple. The surface temperature of each nanocomposite sample was monitored by a separate InGaAs dual-wavelength infrared thermal radiation detector. The authors assume a nominally equivalent emissivity of the nickel substrate and the multilayer nanocomposite, indicating an empirical difference of 0.05. Iwamura et al. then present a thermal balance equation and plot the electrical input power to the heater as a function of the ceramic heater temperature, as measured by the thermocouple, for a nickel substrate without the nanocomposite structure as a control. Excess heat is presented as a function of the heating stimuli and is calibrated as the difference in delivered input power between the control sample and nanocomposite multilayer samples at the same recorded heating temperatures. No neutrons or gamma rays were observed by a thallium-doped sodium iodide scintillator or helium-3 neutron counter (it was not mentioned if the helium-3 counter was moderated).
Samples were loaded with hydrogen gas at between 30 kPa to 250 Pa, depending on desired loading, for ~16 hours at ~250 C. Upon evacuation of the gas at elevated temperatures between ~500 C and ~1,000 C, anomalous heat generation, above the constant input heating power, was observed by the infrared radiation thermometry. Excess thermal power was higher for higher pressuring loading conditions varied for different nickel-to-copper ratios, numbers of thin film layers, and by incorporating calcium and yttrium oxides. Excess thermal power for each sample type was measured at different heating temperatures. The authors argue that the observed relationship is a non-monotonic, convex trend whereby the excess heat appears to peak at an optimal temperature depending on the material system with some sample types (e.g., six-layer CuNi7), not showing a peak in the probed temperature range. The argument is that if the observed excess heat were prosaic and originated from the ceramic heater, one would expect the spurious excess heat signal to go like temperature to the fourth power, as per the temperature dependence of thermal radiation. However, while the excess heat does not follow a fourth power relationship, there is not enough data to confidently fit a convex trend line to the overall dataset. Moreover, the data collected during what seem to be individual trials probing particular local temperature regimes show a linear trend that is noticeably different than the macro trend of data across temperature ranges. It is not clear why this would be the case. More data should be taken to precisely characterize the temperature dependence of the excess thermal power.
Iwamura and colleagues also discuss a methodology for applying a square voltage reduction signal, reducing the heating power, and then returning thermal power to normal. In the case of a bare nickel substrate, the thermocouple temperature and infrared calorimetry slowly return to the pre-perturbation baseline reading, whereas, for the nanocomposite samples, temperature readings spike by roughly 15-20 watts and by a few percentage points above pre-perturbation data before slowly declining. Importantly, the temperature spikes are most prominent for the thermal infrared radiation detectors, as opposed to the thermocouple, indicating the source of the thermal anomaly was in the sample. A second voltage perturbation scheme with successive and equal-magnitude square pulses of voltage reductions and increases was also performed. All temperature probes show time series data of temperature spikes, followed by gradual decay until the next pulse spikes the temperature readings again, resulting in a gradual increase in the apparent baseline temperatures, suggesting a potential cumulative excess thermal energy of approximately 38 kJ.
Lastly, scanning electron microscopy and energy-dispersive X-ray spectroscopy show dark spots in the backscattered images, associated with significant oxygen concentrations between 20% and 40%. In contrast, for locations away from these morphological features and untreated samples, oxygen concentrations are less than 1%. To rule out surface oxidation as a prosaic explanation, the authors analyzed oxidized samples at 700 C, confirmed by an emissivity increase from 0.1 and 0.2 to over 0.5, which yielded oxygen concentrations below 5%. Preliminary data was presented to suggest possible unnatural oxygen isotopic ratios but more experimentation and documentation are required to confidently quantify this observation.
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