I am pleased to report a replication of Mizuno's experiment by H. Zhang:
Excess heat started at ~4 W and has now reached 9.6 W. Be careful when comparing this to the original experiment, because the mass of nickel mesh is smaller. [INCORRECT. THAT WAS A TYPO IN THE PAPER, WHICH I HAVE FIXED.]
The calorimetry is MUCH better than Mizuno's. It is splendid.
Mizuno expressed some reservations about these results because the heat peters out after 2 or 3 hours. He thinks this might be caused by "impure gas in the reactants or slight differences in nickel." I do not think this is a problem because:
- Zhang ran several times with a mesh that produced no heat (p. 18).
- I think the total heat release is too large to be explained as impure gas.
- The reaction is getting stronger between the second and third runs, from 4 W 20 kJ up to 9.7 W 47 kJ. If this were caused by gas coming out of the nickel mesh, I suppose it would fade away. He does not open the cell or change the mesh between runs.
- Zhang replaced the deuterium gas with argon. That killed the reaction. I hope he did not clobber it permanently! Yesterday he told me he went back to deuterium, but it is still dead.