Search for Enhanced D+D+D Reactions under D+ Beam Irradiation into TiDx Targets

To search possible enhancement of three-body D+D+D fusion reaction in condensed matter, we have studied for 10 years about emitted charged particle spectra from titanium-deuterate (TiDx) samples under low energy D+ beam irradiation. By gas loading technique with changing temperature, we prepared TiDx samples with x = 1.4 - 1.8. A TiDx sample was mounted in a vacuum chamber with cooling and irradiated with 70 – 300 keV D+ beam. A delta-E and E type counter telescope using two Si-SSD detectors was used for charged particle spectroscopy. Charged particles from D+D fusion reactions, e.g., 3MeV protons and 1MeV tritons were observed in every case, as usually expected. Sometimes, in addition, we observed “unknown” peaks at about 4.8MeV, which were identified to be two kinds of particles, i.e., helium and triton. We could not find any candidate reaction channels in two-body nuclear reactions of D+ beam and possible target nuclei (H, D, T, He-3, Li-6, Li-7, Be-9, C-12, N-14, N-15, Ti, etc.) including impurity reactions. We concluded that the 4.8MeV particles were from the D+D+D fusion to the out-going reaction channel of He-3 (4.75MeV) + T(4.75MeV). The yield ratios of [3D]/[2D] were obtained as a function of D+ beam energy in the range of 50 to 300 keV, revealed the increasing trend in the lower energy range than 100 keV and were on the order of 1E-4 which was anomalously large compared with the estimated values on the order of 1E- 30 based on the conventional random nuclear process for the cascade reactions of three-body interaction, i.e, D+D to He-4* and He-4* + D reactions.