Maybe a simpler theoretical approach would be to consider spin-aligned superconducting electrons functioning like muons. Interesting that H-absorption by Ni removes its ferromagnetic properties (Skoskiewicz) suggesting that protons disrupt the electron spin alignment normally giving rise to the magnetic fields. At high H loading the electrons become superconducting (as Cooper pairs) so are then capable of drawing adjacent deuterons/protons close together enough to initiate tunneling through the C-barrier and thus fusion. Whether hydronium ions are involved or not its certainly worthwhile studying other H/D absorbing superconductors for LENR activity.

Preparation of superconducting hydrides of palladium‐nickel alloys under high hydrogen pressures

T. Skośkiewicz

First published: 16 August 1978
https://doi.org/10.1002/pssa.2210480260
Cited by: 9

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Superconductivity in palladium hydride and deuteride at 52–61 kelvin
H. M. Syed, T. J. Gould, C. J. Webb and E. MacA. Gray*
Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan 4111, Brisbane,
Australia
*e-mail: [email protected]
Abstract
We report the observation of conventional superconductivity at the highest temperature yet attained
without mechanical compression, around 54 kelvin in palladium-hydride and 60 kelvin in
palladium-deuteride. The remarkable increase in Tc compared to the previously known value was
achieved by rapidly cooling the hydride and deuteride after loading with hydrogen or deuterium at
elevated temperature. Our results encourage hope that conventional superconductivity under
ambient conditions will be discovered in materials with very high hydrogen density, as predicted
more than a decade ago.
1. Introduction
Conventional superconductivity at about ten kelvin was discovered in palladium-hydride and
palladium-deuteride in 1972[1,2], raising hopes that the high density of hydrogen in metal-hydrides
and compounds containing a high density of hydrogen might lead to metallic hydrogen behaviour[3].
No high-temperature hydride superconductors were found. Prior to the 1986 discovery of hightemperature superconductivity in cuprate ceramics[4], for which the current record superconducting
transition temperature (Tc) is 164 K under high mechanical pressure[5], the highest recorded Tc was
22.4 K[6]. Attention then focused on non-conventional cuprates until the discovery of conventional
superconductivity at 39 kelvin in magnesium-diboride[7], then on the 2008 discovery of iron-based
superconductors[8], with Tc values still not exceeding 58 K despite intense research effort[9].
Recently Drozdov et al.[10] found that 140 GPa mechanical pressure induced conventional
superconductivity in sulfur-hydride at 203 K.
PdHx is superconducting[1] for 0.7 1.0 < Tc(H)) in PdH/D at low temperatures can be
understood in the following way. The potential at the oct site is strongly anharmonic, with a
positive anharmonicity parameter, meaning that the interstitial atom sees a hardening potential as its
total energy increases. The effect is to shift the bulk of the pDOS associated with H/D to higher
frequencies. As shown by Errea et al.[27], this increases ωlog (see §2.2.) somewhat, but also strongly
decreases λ, with the result that Tc is suppressed by a factor approaching ten for H. The heavier D
interstitial sits lower in its potential well and sees a somewhat softer potential, so that anharmonicity
reduces Tc by a smaller factor than for H, resulting in a positive isotope effect.
Here we report the observation of superconductivity at around 54 kelvin in palladiumhydride and 60 kelvin in palladium-deuteride. The remarkable increase in Tc compared to the
previously known value was achieved by rapidly cooling the hydride and deuteride after loading
with hydrogen or deuterium at elevated temperature. Our results encourage hope that conventional
superconductivity under ambient conditions will be discovered in materials with very high
hydrogen density, as predicted more than a decade ago[28].

A new, possibly relevant, paper on potential hi-temp superconductivity in nanoclusters -

(difficult reading)

"Laser technology for low dimensional nanocluster physics"

https://iopscience.iop.org/art…42-6596/1164/1/012025/pdf

Laser technologies had always synergy for low-dimensional lattice collisions based fusion - they're uni-dimensional as well. This is also why I think Holmlid achieves hot fusion so easily.