In a previous paper, a positive columu in Ar glow discharge was analysed by a diffusion equation method and the result showed that cumulative ionization was the most dominant ionization process. Electron swarm parameters used in the analysis, however, were deduced from a Boltzmann equation method neglecting the cumulative ionization.
In the present paper, the electron energy distribution function and electron swarm parameters are calculated by the Boltzmann equation method considering the cumulative ionization. The number density of metastable atoms used in the calculation are deduced from the result of diffusion equation.
It is found that the calculated distribution function and electron swarm parameters by the present calcula-tion differ from those by the previous one at low electric field and high number density of metastable atoms. This suggests that, for the accurate analysis of a positive column in Ar glow discharge, the Boltzmann cquation method fully considered the cumulative ionization is important.

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An investigation was conducted on the formation of controlled plasma and damage-less modification of the surface of a carbon material by this controlled plasma. We developed a method to control the sheath voltage independently of the other plasma parameters. A controlled plasma with high ion density and low sheath voltage was formed by this method. The surface of glassy carbon (GC; bulk density: 1.50g/cm³; intrinsic resistance: 4, 200μ•cm; flexural strength: 1, 700kg•f/cm²) was modified by this plasma. In order to estimate effects of the surface modification, the contact angle of water with the glassy carbon surface and ESCA spectra before and after plasma surface modification were measured. To evaluate the damages to the glassy carbon surface, we observed the surface by SEM and measured Raman spectra.
We controlled Ar plasma to have the high ion density of 6×10¹⁰cm^-3 and the low sheath voltage of 50V. In the case of no control, the sheath voltage is 200V with the same density. The contact angle of water with the GC surface decreases from 60° to 1° (untreated surface: 90°) and the O/C value (ratio of O to C) obtained by ESCA increases from 0.1 to 0.21 (untreated surface: 0.06) as the ion density increases from 1.8×10¹⁰cm^-3 to 6×10¹⁰m^-3. The data show that the GC surface is modified more strongly as the ion density increases. However, the half-width of the Raman band at 1, 360cm^-1 of the GC surface does not appreciably increase, and little morphology change upon increasing the ion density is observed.
These results suggest that damage-less modification can be carried out by using the controlled plasma with high ion density and low sheath voltage.

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The mean temperature of central region of the arc for producing fullerene molecules is estimated through the following procedure. First, particle densities of carbon vapor-helium mixture gas are calculated as a function of temperature for various carbon mixture ratios, assuming local thermal equilibrium. From those particle densities, the spectral power-wavelength characteristics (spectral power profiles) are calculated for various temperatures of 3, 000 to 15, 000K and for various carbon mixture ratios of 10 to 100%. The results show that the spectral power of C₂ is stronger than that of C₊ in the temperature range from 3, 000 to 9, 000 K at a constant carbon mixture ratio of 50%, and that the latter is stronger than the former in the carbon mixture ratio from 10 to 30% at a constant temperature of 9, 000K whereas the former is stronger than the latter in the carbon mixture ratio from 50 to 100%.
Next, the spectral intensity profile of the arc (DC 170 A, graphite electrodes, gap length: 3mm, He, 10kPa) is measured with a monochromator. Then, by comparing the measured spectral intensity profile with the calculated spectral power profiles, the mean temperature of central region of the arc and the carbon mixture ratio are estimated to be 7, 000 to 9, 000K and 80 to 100%, respectively.

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Voltage generated in MIM structures of polymide LB films is analyzed by diffusion of electronic carriers in the LB films. The DC voltage of several hundred milivolts is generated in the MIM and the current in the outer circuit of the MIM becomes nearly constant after several hours. In this paper, first, diffusion constant of the carrier (electron) in polyimide LB films is measured, then diffusion current is decided. On the other hand, conduction current in the LB films due to the generated voltage is measured then conductivity of polyimide LB films is decided. Next generated voltage is analytically calculated in various values of resistance in the outer circuit of the MIM and it coincides with the value measured in the experiments.

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The starting voltage of self-maintaining discharge as a function of pressure, the so-called Paschen curve, was measured in various N₂/CO mixture gases. Paschen curve received the influence by discharge in N₂/CO mixture gas. Conditioning of the electrode surfaces by means of glow discharge was found to be effective to get rid of this variation of the curve. It was ascribed to the effect of the CO molecules adsorbed on the electrode surfaces. Thus, it is argued that the effect to discharge characteristics of the CO admixture in N₂ gas is not limited only to the discharge characteristics as the quenching gas in the discharge space, but consideration of the effect of CO at the surfaces seems also to be important. Positive characteristics of Townsend discharge, which was mentioned previously by us, was observed also in this gas mixture.

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Refractory compound thin films of transition metal nitrides, carbides and silicide were prepared on alumina substrates. Their temperature dependence of electrical resistance were investigated at elevated temperature. The maximum temperature Tc at which the films were stable in air were 200-400°C lower than those in poor vacuum (-10-1Torr). The nitrides of tantalum, hafmium and titanium had generally wide temperature range of ohmic properties in air than their carbides, and Tc of the nitride are generally 100-200°C higher than those of carbides. The nitride and carbide of zirconium were found to have poor ohmic properties and low Tc. On the other hand, titanium silicide films had stable ohmic properties below 900°C in air, however its temperature coefficient of resistance was found to have higher value which was comparable to that of platinum.

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Electrical conduction of PPS films has been investigated in the range of 100-160°C. The results obtained manifests three characteristics dependence on the electric field: low field (0-0.2MV/cm), medium field (0.2-0.6MV/cm) and high field (0.6-1.6MV/cm). No dependence of electrical conduction on electrode materials was obtained in the low and medium electric field regions. The current increses with electric field superlinearly in the medium field region, and ionic hopping has been proposed as the dominant mechanism.
The explicit dependence on electrode materials has been obtained in the high field region, where Au electrode gives larger current than Al electrode. That is, as the current show the dependence on the pos-itive electrode material, hole injection is taken into account for the discussion of the conduction mechanism.

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