Let me start with some statements that I think are fairly accurate. That way errors can more easily be corrected later, when I use those statements to ask some questions and maybe speculate a bit. The muon is a subatomic particle that greatly resembles an electron, except it is about 206 times as massive, and is unstable, with a lifespan of about 2 microseconds. Therefore, anyone who wants to use one in an experiment needs to invest considerable energy into making it. In the 1950s, when a number of experiments were using liquid hydrogen "bubble tanks" to observe various particle-interaction events, it was discovered that a muon could cause some nuclear fusions to occur, in that liquid hydrogen. The discovery was quickly analyzed to determine whether or not the process could become a useful source of energy, but unfortunately, even though one muon might catalyze quite a few fusions during its short lifespan, the total amount of energy produced was inadequate to "pay" for making the muon, by a factor of at least five or six. Finally, it is known that after it catalyzes a fusion reaction, sometimes the muon leaves the scene with considerable energy, and sometimes it doesn't leave the scene at all; it is trapped in "orbit" until it dies. That's a major reason why a muon can't reliably catalyze a larger number of fusions. Assuming the preceding is accurate, I now need to mention that I once ran across an equation (long since forgot where, and I haven't seen it since) that related the probability of a reaction's occurrence to the energy of the particles, after the reaction (the more energy, the less likely the reaction). I knew that the very rare reaction between two deuterons, which might produce a helium-4 nucleus, yielded a quite-large energy of about 24Mev, and I wondered about the ability of a muon to carry enough of it away to increase the probability of that reaction's occurrence. (Never mind that the notion pays no attention to HOW a muon might be a recipient of any of the fusion energy released; see above about "sometimes it leaves the scene with considerable energy".) Anyway, if I used the equation correctly all those years ago, and accurately remember the result, then the conclusion was that D+D-->4He might be possible as often as 25% of the time. Obviously I'd like to know what experimental data is available, about muon catalyzed fusion. Is there any evidence that the process ever directly produces 4He from two deuterons more frequently than the natural 1-in-a-million-odds? What is the maximum energy observed for a muon leaving the scene of a just-catalyzed reaction? And as for speculation, has anyone besides me considered shooting muons into the middle of an inertially-confined implosion event? After all, if a pellet can be squeezed down by a factor of 50 to make nuclear fusion happen from sheer temperature and pressure, then think about adding muons when the pellet has been compressed by a factor of only 7 or 8.... With the nuclei closer together, each muon would encounter 7 or 8 times more of them and could cause 7 or 8 times more fusions to happen, in its normal short lifetime. Thanks in advance; if I haven't skirted the guidelines so closely as to cause this post to be deleted, then I await some interesting replies.