The Wiki entry for muon catalyzed fusion has been updated to include the new advancement of Norront Fusion of Norway, using the techniques of Dr Leif Holmlid of Sweden to produce muons easily and cheaply without the requirement of a beam line.
https://en.wikipedia.org/wiki/Muon-catalyzed_fusion Even though almost no one (that is, no one who needs to raise VC funding) wants to be identified with "cold fusion" these days - clearly what we have in the Norront system should be identified as a version of LENR. Thirty+ years ago, P&F specifically rejected the notion that muons were involved in their technique, and perhaps they were correct on that - but they did not know of the big advance of Holmlid which suggests that it is far easier to produce muons than anyone ever expected. Had the "Letts/Cravens effect" gotten more traction, it clearly bridges the gap between what Norront is doing and what P&F were doing. I wonder if anyone is still pursuing the Letts/Cravens technique? At one time, it was rumored that Industrial Heat (Dewey Weaver) was providing some funds for this work - but with no hint of success. Norront, on the other hand, is on the verge of producing a commercial unit which ironically looks like Rossi's shipping container fusion source. Too bad IH did not get any return for all the risks they took, but who knows - maybe they have invested in Norront as well. Jones