Are claims of cheap muon production correct?

Background

Muon catalyzed fusion is a process, whereby isotopes of hydrogen undergo nuclear fusion thanks to a muon replacing an electron bringing the nuclei within fusion distance. The muon is then ejected and can facilitate a next fusion process. ‘Break even’ has not been achieved yet in spite of the optimization of isotope mixtures and initial muon energy. A main limiting factor is the muon lifetime and the cost in energy of accelerator-based muon production. The possibilities would receive an immense boost toward practical applications if a cheap muon source could be constructed. We challenge a recent publication claiming to have constructed a very intense, yet very ‘cheap’ muon source.

Main text

A recent publication in this journal (Holmlid in Energ Sustain 12:14, 2022, 10.1186/s13705-022-00338-4) promotes the idea that such a source has been constructed and demonstrated. The suggestion is based on a long series of articles by the same author as main investigator. They all center around a spectacular new aggregation state of hydrogen, so called ultra-dense hydrogen (UDH). The claims in the article (Holmlid in Energ Sustain 12:14, 2022, 10.1186/s13705-022-00338-4), as well as in the previous articles, are based on speculations going far beyond the experiments they purport to explain, and on a striking disregard of very well-established facts, both concerning conservation laws, elementary quantum mechanics and the phase diagrams of hydrogen. There are strong arguments why the claimed muon production does not occur and that the suggested evidence for it is a collection of instrumental artefacts.

Conclusion

The muon source suggested by Holmlid (Energ Sustain 12:14, 2022, 10.1186/s13705-022-00338-4) does not produce any muons.