On Thu, Sep 10, 2015 at 1:45 AM, <[email protected]> wrote: You might also get positive ions going the other way that neutralize the > force exerted by the electrons. >
The scenario I had in mind had the lithium ions traveling in this manner. > I think current would be more appropriate than voltage. Note that as the > distance between the nuclei decreased, so would the number of electrons > between > them, given a fixed current density. In short as they get closer together > the > attractive force would decrease, and the repulsive force increase. > Suppose you have hundreds of thousands or millions of electrons flowing in the current, all constrained to nearly two dimensions by z-pinch. If the average charge exceeds a value of -3 between the 7Li and the nickel nucleus, I imagine Coulomb repulsion would be completely neutralized. If it was less than -3, the lithium ion could still be brought closer in. I wonder what kinds of dimensions would be involved in the separation distance in a realistic scenario -- microns, nanometers, fm? You would probably reach a point where there were just enough electrons to > neutralize the charges on the nuclei. Note that this is usually called an > "atom", and we already know that the distance between ordinary atoms is too > large for nuclear reactions at any significant level. > Perhaps you have "molecule" in mind here? A molecule might be thought of in terms of a steady state current of the bound electrons in equilibrium between the two nuclei. In the present scenario we are supposing a current on a scale that overwhelms both the lithium ion and the nickel nucleus (but which will be maintained for a nontrivial amount of time). I.e., unlike the case of a molecule, we're dealing with a system out of equilibrium, so we don't need to feel constrained by what happens in a molecule. You really need to integrate the chance at any given distance over the > entire > separation distance from the closest approach to infinity to get the total > chance. This seems complex. Could something a little less literal do the trick? I like the idea of an interaction "half-life" you mentioned earlier as a long-lived analog to the neutron tunneling cross section. It would be nice to be able (a) to use the results a known experimentally derived neutron tunneling cross section as a function of kinetic energy as a starting point, and then derive the separation distance and approximate lingering time for that cross section. And then (b) somehow use the cross section to fill in for the interaction half-life that we don't have data for. And then (c) with that information obtain a relationship for separation distance and lingering time, which might be something like "time varies with the sixth power of separation distance for a given interaction half-life, so if you double the distance between the two nuclei you'll have to wait longer than the age of the universe for something to happen." That would allow one to produce a nice plot of the separation distance versus lingering time that ultimately goes back to experimentally derived kinetic energies and tunneling cross sections, which would allow one to get a sense of the viability of it all. :) Eric
