An ion sensitive probe (ISP) has been applied to ion diagnostics of the edge plasma of the GAMMA10 tandem mirror device. Since high energy ions are created by ion cyclotron range of frequency heating in the central cell of GAMMA10, a secondary electron repeller electrode is set in to suppress secondary electrons emitted from the collector due to high energy ions. Then secondary electrons are successfully suppressed. The ion flux flowing into the collector is evaluated with numerical calculation of ion orbits. This calculation includes the potential profile near the tip of the ISP. Then a correction factor F ␣ of the ion flux to the free streaming one is determined. The calculation yields V -I characteristic of the collector current. The ion density can be estimated by using the measured ion temperature and the factor F ␣ . Sample data of the ion temperature and the ion density in the edge region of the central cell of GAMMA10 are given. The measurement with the ISP shows that the edge ion temperature of GAMMA10 plasma ranges from 100 to 400 eV, and the ion density from 0.5ϫ 10 10 to 2 ϫ 10 10 cm −3 .

The electrical conductivity of the AgI+BN composite system was measured both at 298 and at 453 K. The electrical conductivity increases with the increase of the volume fraction of AgI at both temperatures. The behaviour of ionic conductivity was analysed based on the generalized effective medium (GEM) theory. The threshold values of the volume fraction for the percolation of ionic conduction were 16% at 298 K and 17% at 453 K respectively. These threshold values as well as the determined power indexes agree with those given by computer simulations for the percolation.

A -conjugated compound with two thioacetate end groups was synthesized using a recently developed method. A selfassembled monolayer (SAM) of corresponding dithiol was prepared by dipping a Au(111) surface for 1 min in a 2 mM dithiol toluene solution formed 30 min after the addition of a drop of 30% NH 4 OH in water to the dithioacetate toluene solution. We investigated electronic conduction through isolated single molecules of the -conjugated compound by statistical analysis of molecular junctions repeatedly formed between a gold tip and the SAM on Au(111) using scanning tunneling microscopy (STM) under ultrahigh vacuum (UHV). The single-molecular conductivity of the -conjugated compound is described as G m ¼ T contact with tip Á T -system Á T contact with substrate Á G 0 according to the Landauer equation. Here, Ts are transmission functions and G 0 is the quantum conductance, i.e., 2e 2 =h. Because of observed high values of G m for the -conjugated compound, we could readily analyze the effect of molecule-electrode contacts on T contact with tip Á T contact with substrate . Namely, we successfully observed the dependence of T contact with tip Á T contact with substrate on binding sites of -S À on a Au(111) surface, i.e., the bridge (or the hollow) and the top sites.

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The spontaneous dendrite fragmentation in solidification from undercooled Si melt was analyzed by time-resolved two-dimensional x-ray diffractometry. For the sample solidified at ΔT=261K, several spots appeared at 1ms after recalescence and the subsequent transition from spots to rings occurred within ∼25ms, which suggests that the fragmentation occurred after recalescence but just at the initial stage of the plateau period. Although the present experiment supported that the driving force for the fragmentation is a capillarity effect at the plateau period, the time scale for the fragmentation differed from the current quantitative prediction.