I got my PhD in the engineering of nuclear fusion reactors (Princeton 1982). The most common version of these reactors use magnetic confinement. Rare isotopes of hydrogen are held in a magnetic bottle at 300 million °C (30 KeV), reacting to produce helium, useful energy, and a neutron. The magnetic bottle and high temperatures are necessary to overcome the repulsion between the hydrogen atoms at the distances necessary for nuclear fusion.

A customer of ours is building a different type of fusion reactor, without high temperatures or a magnetic bottle. They replace a few electrons of the hydrogen with muons — particles that are like electrons, but weigh about 207 times more. Hydrogen fusion is quickly catalyzed, as described in an earlier post. The muons recirculate to catalyze more until they decay or are trapped by an impurity, often helium. 

Our company, REB Research, just shipped a specially made, hydrogen purifier tailored to remove the impurities in this process. Another aspect of the purifier design is that it minimizes radioactive tritium leakage, something that happens when hydrogen (tritium) diffuses through metals. We wish them all success, and wish success to our other fusion customers as well. 

Robert Buxbaum, September 30, 2025