Is cold fusion theoretically possible? The case against it is strong – as strong as the Coulomb Barrier, in fact. This is, in effect the “hill” that the charging particle must get to the top of in rather the same way a roller coaster wagon must have enough speed to get over the next rise. For the roller coaster, the opposing force is gravity; for the particle it is electrostatic repulsion as detailed by Coulombs’ Law. In both cases, what is required is kinetic energy.
On the classical theory of an isolated and positively charged nucleus that a proton (also positively charged) must penetrate, a simple formula for the required energy may be used, depending only on the radius of the target nucleus and the number of protons in it. For a deuterium target, the answer is nearly one million electron volts. That is a lot of energy – figuratively applying one million volts to each and every deuteron in the reaction. In hot fusion, that energy is added by heating but the temperature required is over 11 million degrees! That is so hot that all known materials in direct contact would instantly turn into plasma, which is why hot fusion scientists try to confine the plasma in a “magnetic bottle”. Most of the difficulty with this form of hot fusion is that the plasma sooner or later breaks out of that bottle and the reaction instantly stops. The trick is to keep the plasma confined indefinitely but, as we noted last time, this has yet to be achieved in over 60 years and despite the expenditure of tens of billions of dollars.
A breakthrough in this impasse would occur if the above Coulomb Barrier could somehow be tunneled through. Chemists use the term Activation Energy to denote the minimum energy that must be supplied in order for a chemical reaction to occur. That energy is usually in the form of heat but much of that heat need not be applied if the right Catalyst is present. A good chemical catalyst both lowers the activation energy and speeds up the reaction and, as a further bonus, is not itself consumed. As chemists themselves, it was natural that Fleischmann and Pons were keen to explore any broadly similar ways of lowering the nuclear fusion threshold but let’s be clear about the relative orders of magnitude involved: activation energies for chemical reactions, even for those not assisted by catalysis, are typically a few electron volts while the lowest barrier to deuterium-deuterium fusion is one million electron volts!
When no-one could consistently reproduce their results nor detect significant numbers of fusion byproducts like neutrons, the deuterim-deuterium branch of Cold Fusion basically died. There our story might end were it not for Andrea Rossi and his Energy Catalyzer. In contrast to deuterium on deuterium, the E-Cat is apparently achieving quasi fusion reactions with pressurized hydrogen (protons) on nickel, assisted by a catalyst, resulting in large energy gains. To see that this is an even more astounding claim the original deuterim-deuterium one, we need only note that the Coulomb Barrier for the Nickel-Hydrogen reaction is nearly 7 million electron volts – seven times as much again! Physicists might prefer to use the so-called binding energy of the last nucleon in the most abundant Nickel isotope (Ni58) but, in any case, that value is even greater! In fact, the most stable isotope in the entire periodic table is another Nickel isotope, Ni62. Expecting any of the Nickel nuclei to fuse or split in response to the relatively tiny chemical energies present in the E-Cat is like punching Ayres Rock and expecting it rather than your hand to split down the middle!
Nickel can, indeed, be transmuted into Copper by firing high energy protons at it in the laboratory but this requires an atomic beam from a particle accelerator and results only in microscopic amounts of Copper. Most crucially, the energy required to produce the atomic beam is far greater that the energy released by the reaction. It is, of course, precisely the use of atomic beams in nuclear scattering experiments that has enabled physicists to build up detailed data on the nucleus and the forces inside it. Drawing on this data and the associated theory, established over 100 years of painstaking research and peer review, I, for one, can only conclude that the E-Cat cannot be producing the reported net energy gains by any process yet known to Physics.