A deeper understanding of the physics and chemistry of clusters has been constrained by the inability to observe experimentally the structure and structural variations for size selected clusters. We report here measurements of trapped ion electron diffraction, a technique that presents the possibility to directly observe the evolution of cluster structure with size and temperature. The results of electron diffraction from C 60 ϩ ions stored in a radio-frequency Paul trap are reported. ͓S1050-2947͑99͒50305-3͔

The magnitude of the \/f noise in indium oxide films and ZnO accumulation layers is studied as a function of static disorder. The noise level, of both systems, is much higher than in typical metals even for the diffusive regime. The correlation between noise and static disorder leads us to suggest that incipient localization may play an important role in determining the noise characteristics of diffusive systems near an Anderson transition.PACS numbers: 72.70.+m, 71.50.+t, 72.10.-dThe resistance of many homogeneous metallic systems fluctuates with a normalized power spectrum, Sy/V^, that often exhibits 1// dependence. This peculiar spectral dependence which seems to suggest the absence of a characteristic scale has been a source of fascination and continued debate over the last two decades. While no single model has yet been recognized as fully explaining the details of the phenomenon there is a growing consensus that in the case of metals, the resistance fluctuations reflect motion of defects that couple to the measured resistance via potential variations [1]. It is customary to characterize the magnitude of this noise through the empirical [l] relation

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The evolutions of the kinetics and of the energy distribution of the secondary electrons in argon gas during and following irradiation by a 350 ns 150 keV electron beam pulse have been studied quantitatively. The investigation was conducted by time-resolved infrared interferometry measurement of the secondary electron density for a wide range of experimental parameters and by comparison with a comprehensive time dependent kinetic code. From the comparison it was concluded that triatomic molecular ions play important roles in the kinetic reactions.

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