Search

The magnetic field dependence of nuclear spin-lattice relaxation time in zero-dimensional superconductors of Al is measured. The Zeeman effect of conduction electron is observed. The order parameter fluctuation and the discreteness of one-electron levels are discussed.

The electron density of transient plasma was measured with Michelson type CO2 laser interferometer. The stability of the CO2 laser, the directivity of the laser beam and the accuracy of the density measurement were investigated.

液晶を用いた赤外線計測とくにコヒーレントな赤外光に対する干渉測定とホログラフィについて述べる。コレステリック液晶は面状の赤外線センサであり,これを用いて赤外線干渉計やホログラフィなどが行なわれる。またネマティック液晶の電気光学効果を用いたホログラフィ用の光シャッターかホログラム記録などが可能である。

Etch pits of KCl crystals obtained with dehydrated glacial acetic acid were observed. KCl is so soft, comparing with LiF, that dislocations are generated on it by slight mechanical shocks. Therefore, surfaces of KCl crystal are apt to be contaminated in the sense of the dislocation theory. It is supposed its depth usually reaches 100 µ or more and also most of these generated dislocations are surface half loops and isolated loops. One to one correspondence between etch pits and dislocations is discussed.

An apparatus to measure the ordinary and photo-induced Hall effect on solid electrolyte crystals, ionic crystals, and semiconductors is described. A 75 Hz alternating current and a 50 Hz magnetic field are used, where the induced Hall voltage is observed by use of a phase-sensitive detector operating at the sum frequency of 125 Hz. The apparatus has a noise level of the order of 10-10 V; minimum detectable Hall voltage is shown to be 1 nV. Results of measurements on RbAg4I5 single crystals are also presented.

NMR absorption peak of 27 Al in very fine metallic particles of Al with diameters of less than 100 A is observed to shift in the direction of the zero Knight shift, at temperatures below 3.2°K.

Metal-non metal transition in doped silicon is studied by NMR. The result, together with the static susceptibility measurement and the theoretical interpretation with the Hubbard model, seems to give a sound basis for the Mott transition picture.

Output waveforms of a pulsed H2O laser are observed with an indium-doped germanium detector. The waveform is subject to a remarkable undulation and its frequency varies with the discharge current and conditions of the resonator rather than with the wavelength of emission. It is found that the undulation is interpreted as the beat between laser oscillations of different transverse modes. Since the maximum electron density of order 1012 cm-3 in the laser tube produces a change in refractive index of order 10-6 in the far-infrared, the radial distribution of the electron density is responsible for the change in beat frequencies between transverse modes. Effects of the electron plasma in the optical resonator are theoretically given and applied to explain the observed results.

Construction and operating characteristics of far-infrared masers with water and deuterium oxide are presented. The maser tube is 5 cm in inner diameter with internal mirrors of about 5 m separation. The concave spherical mirrors of 6 cm diameter are used. Under the pulsed excitation of 5∼10 kV with 40 µs duration through the water vapor at about 0.2 Torr, strong maser oscillations are obtained at 47.4, 78.4, 79.1, 118.7, 120.1 and 220 µm wavelengths in H2O, and at 36.4, 72.7, 74.5, 84.3, 107.7 and 171.6 µm in D2O. Output characteristics against the gas pressure, the excitation voltage, and the longitudinal magnetic field are shown. At the optimum operation with the longitudinal magnetic fields peak output powers at 118.7 and 171.6 µm are estimated to be as large as about 3 and 6 W respectively.

Infrared holography by using CO2 laser radiation (10.6 µm) is demonstrated. Cholesteric liquid crystals having a response range from 26°C to 31°C and 34°C to 37°C are used as a holographic recording medium in the infrared wavelengths. A hologram represented on the liquid crystal detector is then recorded photographically on an ordinary film and is reconstructed by a 6328Å He–Ne laser beam. It is shown that the observed values of demagnification and the positions of reconstructed images of the IR holography are well represented by calculations based on the Meier's theory.