$d$-D nuclear fusion events were observed in an electron-screened, deuterated metal lattice by reacting cold deuterons with hot deuterons $\left(d^{*}\right)$ produced by elastically scattered neutrons originating from bremsstrahlung photodissociation (where “d” and “D” denote ${}^2\mathrm{H}$). Exposure of deuterated materials ($\mathrm{Er}{\mathrm{D}}_3$ and $\mathrm{Ti}{\mathrm{D}}_2$) to photon energies in the range of 2.5–2.9 MeV resulted in photodissociation neutrons that were below 400 keV and also the 2.45-MeV neutrons consistent with ${}^2\mathrm{H}(d,n){}^3\mathrm{He}$ fusion. Additionally, neutron energies of approximately 4 and 5 MeV for $\mathrm{Ti}{\mathrm{D}}_2$ and $\mathrm{Er}{\mathrm{D}}_3$ were measured, consistent with either boosted neutrons from kinetically heated deuterons or Oppenheimer-Phillips stripping reactions in the highly screened environment. Neutron spectroscopy was conducted using calibrated lead-shielded liquid (EJ-309) and plastic (stilbene) scintillator detectors. The data support the theoretical analysis in a companion paper, predicting fusion reactions and subsequent reactions in the highly screened environment.

• Received 15 October 2018
• Accepted 6 December 2019

DOI:https://doi.org/10.1103/PhysRevC.101.044610