Density effect in d–dd–d muon-catalyzed fusion with ortho- and para-enriched D2

The ortho–para dependence of d–dd–d fusion neutrons time spectra was investigated in wide range of the target densities at similar temperatures [ϕ   = 0.86 liquid-hydrogen density (LHD), T=35 KT=35 K for liquid and ϕ=0.03–0.17 LHDϕ=0.03–0.17 LHD, T=36 KT=36 K for gas]. The result showed significant density dependence. For the first time, a delayed transient structure in the spectra that depends on the ortho ratio, presumably due to the slow dμ thermalization, was found in gaseous D2, whereas no significant structure was observed in liquid. The resonant ddμ formation rates in the gas phase were extracted considering the structure.