Cluster-Impact Fusion and Effective Deuteron Temperature

Temperature and kinematic line broadening are the primary contributions to the width of the proton energy spectrum measured in cluster-impact fusion experiments. By ascertaining these two contributions, we have determined an effective temperature for the high-velocity deuteron component that is responsible for the measured fusion yield. The extracted effective temperature is substantially higher than conventional estimates., and implies that cluster-impact fusion is hot fusion on an atomic scale. The proton spectrum rules out contaminants in explaining the high yield.Comment: 11 pages, 2 figures. PACS numbers: 79.20.RF, 25.45.--z, 47.40.Nm, 52.50. L

Non-thermal photodesorption of N{sub 2} from Ag(111)

The authors have measured translational and rotational energy distributions of N{sub 2} molecules following desorption from a Ag(111) surface by infrared (1,064 nm) radiation. The observed desorption yields were large even at laser fluences far below that required for laser induced thermal desorption. State resolved laser techniques using coherent VUV radiation showed that the rotational and translational energy distributions of the desorbing N{sub 2} molecules are not consistent with the predictions of the heat diffusion model governing laser induced surface heating. These results suggest that physisorbed adsorbates can couple directly to the nascent phonon distribution or the nascent electron-hole pairs in the photoexcited substrate without heating of the surface