Experimental Search for μd 3 He Fusion

The vast majority of muon catalyzed fusion research has been concerned with muonic molecules of hydrogen isotopes only, since the dynamics of higher-Z muonic atoms in general preclude the formation of molecular systems. In the specific case of hydrogen–helium mixtures, bound muonic molecular states can exist, and thus it is possible to search for the reaction μd 3 He μ+α(3.66 MeV)+p(14.64 MeV). Until recently, the theoretical predictions for the nuclear fusion rate in the μd 3 He molecule, λ̃ f , ranged over one order of magnitude, from 10 5 to 10 6 per second. An experimental upper limit has been measured for λ̃ f in HD + 3 He giving a value (<6×10 4 s −1 [1]). We report on the analysis of an experiment in D 2 + 3 He which has shown a signal coming either from the muon catalyzed reaction, or from the fusion in flight of 3 He's formed from dμd fusion.