Search for nuclear fusion in deuterated targets under cluster-beam impact

Stimulated by the recent report of Beuhler, Friedlander, and Friedman on the observation of dd fusion under the impact of heavy-water clusters on deuterated solid targets, we undertook a similar study with pure deuterium clusters (${\mathrm{D}}_{200}^{+}$–${\mathrm{D}}_{300}^{+}$) in the same range of incident energy per deuteron (less than 1 keV). We observed no fusion event and our upper limit for the fusion rate is more than 1 order of magnitude below the Brookhaven value. Additional measurements performed with ${\mathit{N}}_{\mathit{n}}^{+}$ projectiles were not conclusive but showed that beam-contamination problems may be very serious.