This paper describes the study framework for material property measurements related to spacecraft charging, methods, and measurement results. This report introduces a summary of some typical measurement results following a brief explanation of the measurement project.

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This paper describes an uncooled infrared (IR) camera especially optimized for small size & weight, less power consumption without degrading noise equivalent temperature difference (NETD). This camera has two features, including a wafer-level chip scale vacuum package with 160x120 SOI-diode array and germanium lid for good IR transmission, and also a real-time signal correction capability with respect to ambient temperature. These features enabled the considerable size/power consumption reduction and the operation without thermoelectric cooler (TEC) which usual IR cameras require for temperature stabilization. As a result, we realized compact infrared camera (less than 71grams) with low-power consumption and excellent NETD of 22 mK (F/0.8 optics).

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The temporal spectroscopic characteristics of the terahertz pulse transmitted through the metal hole array is investigated by using the THz time domain spectroscopy in combination with the short-time Fourier transformation. It is found that the THz wave at around the resonant frequency of the surface plasmon-polariton (SPP) delays compared with that at higher frequency region. From the dependence of the delay time on the thickness of the metal hole array and the frequency, the delay at the SPP resonant frequency is attributed to the deceleration of the group velocity of the THz wave in the metal hole.

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This paper describes an effort for development of a thermal imaging equipment aboard a high speed vehicle to detect anomalous regions in concrete structures of road tunnels. This type of infrared equipment would be required for the use of tunnel safety inspection with no traffic regulations on real expressways. Presented in this paper are theoretical analyses of the detection capability for inner thermal anomalies in the concrete wall, discussions on applicability of infrared detectors and on optimum scanning schemes for the imaging system, and finally, results of design and prototyping of the equipment along with field data.

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Simultaneously oscillated multi-line far infrared (FIR) lasers from a single FIR laser cavity have been developed as optical sources of a two-color interferometer for plasma diagnostics. Using two pump CO₂ lasers which oscillated at the different wavelength, we have obtained simultaneously oscillated 119-μm laser pumped by 9P(36) CO₂ laser and 57-μm laser pumped by 9R(8) CO₂ laser from mixed gases of CH₃OH and CH₃OD. Common beam splitters of the two-color FIR laser interferometer have been designed by using precise optical constants (refractive index and absorption coefficient) of silicon.

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Biological imaging with a method for diffusion optical tomography is demonstrated. The present method is based on weight function of discrete model for scattering tissues. The weight function is given as a product form between sensitivity function and optical mean path length. The method is applied to two-dimensional imaging for inhomogeneous media by simulation. As results of the simulation, it is verified that the present method can extract parts with stronger absorption coefficient from backgrounds.

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Radiation of the electromagnetic waves (THz waves) in the terahertz frequency region from atomic clusters illuminated by intense femtosecond laser pulses is studied. The power of the THz wave from argon clusters is ∼40 times larger than that from argon molecular gas. The enhancement of the THz radiation originates from strong laser energy absorption by the clusters. The angular distribution of the power and the polarization state of the radiated THz wave are compared to the predictions of the several models of the THz radiation from the laser produced plasma.

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In this paper a spatial filter to discriminate similar textures is proposed. This spatial filter is composed by based on the linear prediction method. We have done two kinds of experiments to show the effectiveness of this proposed method. One is to the textures generated form the 2-dimentional random noise, and the other is to the texture recomposed from the Brodatz's texture. In the results it is showed that the proposed method is useful for both of the isotropic and an-isotropic textures.

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We have developed a 3-D electromagnetic field measurement system using 2-D lock-in amplifier. This system uses an amplitude modulated electromagnetic wave source to heat a resistive screen. A very small change of temperature on a screen illuminated with the modulated electromagnetic wave is measured using an infrared thermograph camera.
In this paper, we attempted to apply our system to microwave imaging. By placing conductor patches in front of the resistive screen and illuminating with microwave, the shape of each conductor was clearly observed as the temperature difference image of the screen. In this way, the conductor pattern inside the non-contact type IC card could be visualized. Moreover, we could observe the temperature difference image reflecting the shape of a Konnyaku (a gelatinous food made from devil's-tonge starch) or a dried fishbone, both as non-conducting material resembling human body. These results proved that our method is applicable to microwave see-through imaging.

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Thermograph shows the radiant temperature distribution of the observed surface, including the influence of the reflection from the surroundings. In this study, the method to generate the surface temperature images from 3D thermograph is developed. First, three-dimensional geometric model of the built environment space is generated by the stereo photography method using spherical thermograph system. The observed thermal images, which have the accurate coordinate information, are matched with 3D geometric model, three-dimensional thermal image is then generated. The directional emissivity and reflectivity data, which are the essential factors for the surface temperature calculation from radiant temperature, are obtained for several architectural materials through the measurement. The influences of reflection from the surroundings on the radiant temperature in the thermal image are removed by the ray tracing in the three-dimensional thermal image using the directional emissivity and reflectivity data, the three-dimensional surface temperature image is then completed. The calculation accuracy of the surface temperatures and the effectiveness of this conversion method are confirmed.

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A PbTe/PbS multilayer mirror was prepared by Hot Wall Epitaxy. A reflectivity as high as 99% in the mid infrared region was obtained using about seven periods of the multilayer structure, owing to the relatively large difference in the refractive index of PbTe and PbS. Such a mirror has potential applications for electrically pumped EuTe/PbTe vertical cavity surface emitting quantum cascade lasers.

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A new high current type pulsed neutral beam injection device has been developed using washer gun for the plasma source. We extracted the maximum beam current of 3.7A for then acceleration voltage of 10kV successfully. We confirmed from examination of experiment results that aim specifications (15kV, 20A) are enabled by the improvement of some device conditions.

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The absorption characteristics of sulfur dioxide (SO₂) and sulfur trioxide (SO₃) in the infrared region were measured using a quantum cascade laser and an absorption cell of length 1 m heated to 150°C. The laser was scanned over the wavelength range 6.9-7.4 μm, which included the absorption bands of SO₂ and SO₃. Measurement results showed that the absorption bands of SO₂ and SO₃ partially overlapped, with peaks at 7.28 μm and 7.35 μm for SO₂ and 7.14 μm and 7.25 μm for SO₃. These results showed the possbility of using infrared laser absorption spectroscopy for measurement of sulfur oxides (SO_x) in flue gas. For SO₃ measurement, infrared absorption spectroscopy was shown to be more suitable than ultraviolet absorption spectroscopy. The absorption characteristics of open air in the same wavelength region showed that the interference due to water vapor must be efficiently removed to perform SO_x measurement in flue gas.

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The experiment was aiming for making anisotropic magnet by using hot-forming process. And this experiment was carried out to investigate the effects of Cu addition, and hot-forming temperature on magnetic properties of Didymium-Fe-Co-Nb-Y-B and Didymium-Fe-Co-Nb-V-Y-B alloys. The results are summarized as follows:1) In the X-ray diffraction patterns which were taken in the direction of applied compressive stress in the hot-forming process, large peaks corresponding to (004), (105) and (006) planes were observed. These planes are facing the direction of the c-axis of the Nd₂Fe₁₄B-type crystal. These observations suggest that crystallites are oriented toward the c-axis by the hot-forming process.2) The optimized preparatory conditions for the anisotropic magnet Di_12.5Fe_68.3Co₁₀Nb₁V₁Y_0.7Cu_0.5B₆ are as follows: roller velocity in the process of preparing the melt-spun ribbons : 25 m/s, and temperature of the hot-forming process: 840°C. Typical magnetic properties of the anisotropic magnets obtained: J_r=1.041T, H_cJ=812.5 kA/m, H_cB=561.7 kA/m, (BH)_max=176.8 kJ/m³, (J_r - J_r')/J_r × 100 =54.5 %. The α-Fe type phase is contained several percent in the sample. Good results are obtained in this study, which can be related to the industrial “die-upset process”.

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The three-dimensional polycrystal magnetic field analysis method is compared with the distributed magnetic measurement. In the three-dimensional polycrystal magnetic field analysis method, the local coordinates are fixed in each crystal grain and the global coordinates are defined in the polycrystal steel. It is assumed that each crystal grain has the same magnetic characteristics as those of a single crystal grain. When it is applied to the real grain oriented (GO) steel with two crystal grains and with 56 crystal grains in 80-mm × 80-mm, and with 0.35 mm thick, their results of the magnetic flux density distribution and the inclination angle are mainly explained by α angle distribution of the polyctristal steel and seem to be in good agreement.

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Practice is very important in education because it not only can stimulate the motivation of learning, but also can deepen the understanding of theory. However, due to the limitations on the time and experiment resources, experiments cannot be simply introduced in every lesson. To make the best use of multimedia technology, this paper designs five virtual experiment systems, which are based on the knowledge of physics at the high-school lever, to improve the effectiveness of teaching data processing. The systems are designed by employing the cognitive theory of multimedia learning and the inner game principle to ensure the easy use and to reduce the cognitive load. The learning process is divided into two stages: the first stage teaches the basic concepts of data processing; and the second stage practices the techniques taught in the first stage and uses them to build a linear model and to carry out estimation. The virtual experiment systems have been tested in an university's data processing course, and have demonstrated their validity.

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Effects of a charged metallic particle of milli-size on sparkover characteristics under dc quasi-uniform gap of 2 cm long in atmospheric air. The results show that the sparkover voltage depends on the position and charging of the sphere particle of 0.1 or 0.2 cm in diameter along the gap axis. Ions generated by natural radiation in the gap lead to charge the metallic particle and contribute significantly to the sparkover voltage depending on the humidity in air. With the high humidity, the particle is quickly charged and the sparkover voltage falls in lower than half of the voltage without the metallic particle.

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