The "dogbone" seems like a relatively simple reactor, but it could be rather complex in operation if it depends on SPP formation and positive feedback. SPP would be expected to form in two main places - the interface of the resistance wire with ceramic outside the tube, or also on the interior wall of the tube - but only if that wall is electrically conductive AND is carrying current - in the presence of photon flux from the heating wire. (The current would be AC, induced from the resistance wire). In fact, the outer location could be powering the interior location with SPP and each having positive feedback to the other.
The role of lithium-aluminum (besides being the hydrogen source, as a hydride) could be twofold, in the Parkhomov reactor. It could be a nuclear reactant, but proof of that awaits isotope analysis. It could also be the needed electrical conductor - if it is deposited in the correct thickness. In short, there could be evidence of nuclear reactions of lithium and hydrogen - or not. In hot fusion, it is known that hydrogen (as opposed to deuterium) does not readily react with lithium, and that would suggest that lithium would play the other critical role. That critical role would be as a conductive thin film (deposited as an alloy with aluminum) on the interior wall of the tube. The high vapor pressure of molten LiAl alloy suggests that it could be deposited correctly in thickness of tens of nm. It that is true, then the main function of lithium alloy could be to promote the Kretschmann geometry for SPP optimization. The Kretschmann geometry requires a thin film of conductor which will transmit light. A thickness of 50 nm works for gold. http://www.doctorlighthouse.com/kretschmanngeome.html This could be a reason why adding more LiAlH4 (more than 1/10 gram) could be counterproductive and probably would quench the reaction. There is enough hydrogen in the tenth gram to provide about a megawatt-hour of thermal energy when it is reduced to the DDL so we do not need more hydrogen. And if SPP is the mechanism that reduces hydrogen to DDL, then we do not need more lithium aluminum - since the deposit would be too thick. Prediction for Parkhomov: if a more sensitive GM meter can be obtained to look for soft x-rays in the range of 3.6 keV - they will be found. The normal meter will miss this radiation spectrum.
