In reply to R.C.Macaulay's message of Sun, 30 Sep 2007 19:37:55 -0500: Hi, [snip] > >Robin wrote.. >>It can't be any more than the chemical binding energy of hydrogen to the >>lattice. A few eV at most.
When the lattice springs back, it's not going to yield any more energy than it took to expand it in the first place. In fact you also need to break the Pd-H bond, though that will largely be compensated for by the formation of H-H bonds. These energies are not large. To rip Pd atoms apart altogether, you need to vaporize it, which happens at 2940 deg. C. That implies an average energy of 3/2 x k x 3213 K = 0.415 eV /atom. You can expect much less from contraction. Even if a few atoms all contract at once, you need to consider that the amount of contraction will get less as you get farther from the emission point. My guess would be that by the time you are three lattice cells removed, the contribution would be negligible. Even 3^3 = 27 * .415 eV is only about 11 eV. That's not even going to make a dent in the Coulomb barrier. [snip] Regards, Robin van Spaandonk The shrub is a plant.
