High resolution image devices have been required in the region of imaging under radiation. So we have developed 213 inch MF (Mixed Field,same as MS) high resolution chalnicon, the type No. of N4182, which is suitable for radiation tolerant imaging. N4182 can be used reliably under radiation up to 10^5R/h and even after the accumulated exposure of 10^8R. In addition to those, this tube has such excellent features as high sensitivity(0.15 μA/lx), high resolution(1150 TVL when a scanned area is 6.6x8.8mm^2) and maximum operating temperature of 85℃.

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In this report, some properties of the avalanche multiplication photodiode operated in a charge storage mode are studied. Consequently, it is found that the use of the APD as the photo element is useful to obtain a highly sensitive image, because the wide dynamic range and the reduction of the excess noise areexpected.

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ZnS:TbF_3 thin films were observed using TEM and X-ray diffraction. Strcture of TbF_3 was investigated. Accordingly the following results are obtained, (1) Tb atoms or pa rticles disturb the formation of recrystalization of ZnS film. (2) The structure of TbF_3 b elongs to YF_3 type orthorhombic system.

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Color plasma display panels utilize vacuum ultraviolet Xe resonance photons to excite phosphor. Trapping effect of these photons in the panels causes luminance saturation, efficiency decrease, and also enhances color cross-talks at values of discharge current. It is difficult to analytically trace photon trajectories in the plasma displays, mainly due to complicated panel structures. In this report. Monte Carlo simulation technique is used to calculate number of photons arriving at the phosphor in plasma display panels which have square barrier ribs. The saturation of luminance and decrease of luminous efficiency are checked in detail, and compared with theory. Structural requirements for reducing the luminance saturation and color cross-talks are also discussed.

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Surface-Discharge plasma displays have the characteristics such as wide viewing angle,and they are recognized as leading display devices for full color display with a large areas. A Barrier Ribs electrode ac plasma display with the new structure of electrode has the advantages of high luminance and high luminous efficiency. Then we analyzed the action of the barrier ribs electro de plasma display by the computer, and obtained high luminance and high luminous efficiency compared with surfa-ce-Discharge plasma displays, because of the result of the surface potential, wall discharge, and the variation of light emitting region.

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The most important problem for the DC-PDP is how to extend its life. We have earlier reported that it can be resolved by means of a resistor-in-cell panel with high gas pressure. We conducted theoretical studies on cathode sputtering, which determines the life, with regard to deterioration of the luminance and other characteristics. A two-dimensional cell model was adopted. Sputtered cathode atoms diffuse in accordance with the solution of a diffusion equation and deposit the cell walls. A stationary state solution is obtained. The luminance decay curve obtained from the solution agrees with the measured one. A theoretical expression of life in terms of the pressure and current is obtained from a sputtering rate study by Townes. This expression agrees qualitatively with the experiments. The theory is applied to the AC-PDP.

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