In the present review, the necessity of surface analysis, basic problems on knock-on effect and sputtering phenomenon and a quantitative analysis are discussed from the viewpoint of ion microprobe mass analysis (IMA) in metallurgical study. Examples of the application of IMA are also given for the following topics; analysis of the hydrogen induced cracking, hydrogen as an element, grain boundary segregation and oxidation films in metallurgical study.
Macroscopic behavior of a constricted arc and a plasma jet operating in argon, is studied by high speed photography. When the arc current is increased, the takeover mode predominates in general, the pressure at the axis of an arc column is increased by the influence of the thermal pinch effect, meanwhile the anode arc terminus location recedes to the entrance of the nozzle constrictor. When the gas flow rate is increased, the restrike mode is most likely to occur, so the axial velocity of the anode spot maintains at a high value and the magnitude of travel keeps relatively large. The axial fluctuation range of a plasma jet is correlated with the travel length of an anode spot moving back and forth on the nozzle constrictor wall, and the frequency of the fluctuation synchronizes with the arc mode.
A new multicolor liquid-crystal display device is described. The device is of a field-in-duced tunable birefringence type and employs a unique hybrid-aligned nematic (HAN) electro-optical cell between polarizers. The cell consists of two electrode substrates sandwiching a nematic fluid with either a positive or negative dielectric anisotropy, the two substrates hav-ing homeotropic and homogeneous boundary surfaces, respectively; thereby the nematic direc-tor is varied continuously, lying perpendicular to one substrate and parallel to the other. The multicolor display based on the HAN has such practically favorable features as remarkably lower driving-voltage, easier tolerance for fluctuation of operational conditions, and higher brightness of colors compared to previously described color liquid-crystal displays.
Experimental studies on the gain coefficient of an after-mixing-type CO2 gasdynamic laser are described over a wide range of various parameters. The population inversion could be generated by mixing (CO2+He) into a supersonic N2 flow, which is cooled by rapid expansion through a Lavel nozzle. The gain coefficient was found to depend on the distance from the mixing holes, and the flow rate of (CO2+He). With the increase of (CO2+He) flow rate, the gain coefficient increased linearly, and the distance from the holes for maximum gain coefficient decreased. The region where the gain was observed to be positive extended about 30cm along the flow axis, and the maximum gain was 0.8m-1 at 111mm downstream from the holes. An analysis of the gain coefficient was conducted from the measurement of the pressure and the flow speed along the flow axis.
HgTe crystals were epitaxially grown on various single-crystalline materials in an atmosphere of hydrogen gas flow. The close-spaced technique of a confined type was employed for the crystal growth. A growth rate of 5μm/hr was achieved at a substrate temperature of 360°C and a transport rate of source HgTe of 10mg/hr. Single crystals of InSb, GaAs, InAs, CdTe, CdSe, Ge, KBr and NaCl were used as the source material. However, epitaxial growth of HgTe took place only on InAs, CdTe, and CdSe substrates in the growth temper-ature range (from 320° to 420°C) of our experiments. Hall measurements on the HgTe layers grown on the (100) faces of InAs showed that the layers were all n-type and had an electron mobility of about 25, 000 cm2V-1sec-1 at 300K.
A new type of compact TEA laser, which has a ladder-type pre-ionization discharge circuit and a special low inductance circuit for laser gas pumping discharge, are developed. Uniform glow discharge input up to 265 J/l•atm is achieved within a volume of 2×2×60 cm for an arbitrary laser gas mixture and even for pure CO2 gas. Maximum laser power 10MW is obtained for the mixture ratio of CO2:N2:He=2:1:4. Saturation energy of 400 mJ/cm2 are obtained for a 70 nsec normal Q-swiched pulse with a low-power tail of 1μsec, and 35 mJ/cm2 for a 2 nsec single pulse. Output laser energy is improved about 30% using tri-n-propylamine as a low-ionization seed gas. A maximum output energy of 21J/l•atm is achieved. Steady stable operation of up to 40, 000 shots in 1_??_2 pps has been obtained.
A magnetic shielding case, which is made of mu-metal, was fabricated in order to screen out the terrestrial magnetic field and thus to allow the production of a uniform magnetic field for the Cs primary frequency standard. The total length of the outmost case is 1.5m. The uniformities of the residual fields and the shielding factors were measured with a flux gate type magnetometer for two positions of the shielding assembly with respect to the ter-restrial field. For the transverse field, the shielding factor is about 6, 000, and the maximum variation of the residual field is 2×10-3A/m when the case has been demagnetized with a current of 10A AC. For the longitudinal filed position, the shielding factor is about 200, and the uniformity is approximately ten times poor than for the transverse field. The uni-formity of the residual transverse field satisfies the requirement for the Cs primary frequency standard.