Publication Type: Government Report
Research Type: Experimental
Solid State Fusion Type: LENR/Cold Fusion
Reactor Set-Up: Electrolytic Cell
Observables: Excess Heat (power and/or energy), He4 Gas, X-Rays, Tritium
Stimulation: Current (constant)
Material: Palladium, Palladium alloy
Isotopic Hydrogen Reactants: D2O
Summary: "Miles and colleagues synthesize work performed at the Naval Air Warfare Center Weapons Division in China Lake, California on anomalous heat and helium-4 production in heavy water electrochemical experiments using alloyed palladium cathodes and a lithiated electrolyte. The China Lake team used open isoperibolic calorimetric system to measure excess heat.
Multiple heavy water electrolysis experiments measured excess heat with reasonable repeatability for particular batches of palladium stock with no anomalous effects under control light water electrolysis. However, reproducibility in excess heat from cathode to cathode was a challenge and certain materials, especially palladium rods from Johnson-Matthey and palladium-boron alloyed cathodes from the Naval Research Laboratory, showed superior results lending credence the importance of metallurgy. Excess heat events occurred after many days of continuous electrolysis. It was postulated that repeated cathode loading and de-loading is important due to the observation that some cathodes only showed excess enthalpy after prior failed trials and because of a pre-experiment protocol of cathode and anode polarity reversals driven at high current densities.
Correlation of excess enthalpy to helium-4 evolution, an expected nuclear product of deuteron-deuteron (DD) fusion, in heavy water electrolysis was carried out using gaseous mass spectrometry analysis at multiple laboratories. Initial helium-4 measurements by Miles et al. were critiqued by Jones and Hansen because the reported detection limit of 0.1 parts per billion (ppb) was below that of the expected helium diffusion through the pyrex bottles containing the gas. Control experiments in light water and failed excess heat experiments, performed after successful trials, yielded null results for helium detection. However, if the initially reported detection limit was correct, all control experiments should have been found to contain helium from atmospheric diffusion. Furthermore, flasks filled with protium gas, a mixture of deuterium and oxygen gas, and nitrogen gas showed helium diffusion rates largely in agreement with theoretical expectation, showcasing that the initially reported detection limits were too small. Four pyrex flasks filled with nitrogen were stored for nine days and one was reported to be positive for helium, resulting in a minimum detection limit based on the experimental diffusion rate of 3 ppb. For five control experiments with gas stored in metal flasks, preventing significant helium diffusion, the background helium concentration was ~4 ppb. In later excess heat experiments, helium-4 measurements at the Rockwell International Corporation produced background subtracted helium-4 measurements, corrected for atmospheric diffusion during shipping, of 2-5x10^11 helium-4 atoms per joule of excess heat, nominally in agreement with the theoretical value 2.6x10^11 for DD fusion producing helium and 23.8 MeV of energy. A batch of excess heat producing cathodes using metal flasks for helium-4 measurements reported 25% to 200% above background concentration.
The largest excess heat experiment took place a in palladium-boron alloy and another significant excess event, which produced an estimated 1.1 MJ, was observed in a palladium-cerium alloy, however, the latter was the only excess heat experiment that showed no signature of helium production. Anomalous X-radiation was observed in some experiments using X-ray film, Geiger Mueller counters, and NaI scintillator crystal detectors and was never witnessed when experiments were not active."
