bluuebunny/crossref_metadata_2025 huggingface dataset:
Deterioration of GaAs Esaki Diodes
Authors: Shibata Akikazu
Published: November 2005

The deterioration of GaAs Esaki diodes is caused by the rapid diffusions of interstitial impurities. Among the diffusion processes involved, the electric-field-assisted diffusion of interstitial Zn which acts as a donor is the most important one. The migration of impurities produced intermediate states and a defect level or levels, most probably a trap level, in the forbidden band. This defect level is then responsible for the vicinity peak at about 0.5 V found in deteriorated samples. Vacancies at and in the vicinity of a junction act against deterioration. It is found that a quantity C/n
I
p, where C is the junction capacitance measured at the valley in p
f, n=I
p/I
v, I
p and I
v the peak and the valley currents in ma is a useful measure of deteriorability of GaAs Esaki diodes. A GaAs Esaki diode with C/n
I
p<0.35 deteriorates significantly while a unit with C/n
I
p<0.8 will not.
Pulse Shortening Effect in Linear Accelerators
Authors: Hirakawa Hiromasa
Published: November 2005

The injection current into an electron linear accelerator has a threshold beyond which the emerging accelerated beam is unstable in the latter part of the pulses, resulting in partial or complete loss of the output current. The experiment and the theoretical analysis show that the effect is due to RF excitation of the accelerator in an unwanted mode. Several ways to suppress the excitation are discussed.
Some Characteristics of a Duoplasmatron Ion Source
Authors: Tawara Hiroyuki
Published: November 2005

A Duoplasmatron ion source capable of producing about 10 mA of hydrogen ion beam has been constructed and tested. The effect of a resistance which connects the intermediate electrode and the anode has been studied. The ratio of the anode current to the total arc current is strongly influenced by the value of the resistance. It is shown that the intermediate electrode of the Duoplasmatron ion source plays the same role as a grid of the electron tube or an ignitor of the mercury rectifier. Changing the resistance periodically a high intensity pulsed ion beam has been obtained from the Duoplasmatron ion source.
Theory of a Parallel-Plate Plastometer for Bingham Body
Authors: Oka Syoten , Ogawa Sekiko
Published: November 2005

It is shown how to determine the yield value f and the plastic viscosity η of a Bingham body by means of a parallel-plate plastometer. Calculation have been made starting from the general equations of motion for Bingham body, and the relationship between the thickness h of the specimen and the time t has been obtained when a constant force is applied perpendicularly to the plates. Calculations have been made for the two cases: a) The plates are larger than the specimen; thus the volume of the specimen between the plates is constant. b) The specimen is larger than the plates; thus the area under compression is constant. The formulae are reduced to the well-known equations derived by Stefan and Healey for Newtonian liquid in the limit f→0.
A Paraffin-Moderated 4π-Neutron Detector
Authors: Teranishi Eizo , Furubayashi Bunji , Michikawa Taichi , Kageyama Misao , Yura Osamu
Published: November 2005

A flat response 4π-neutron detector has been constructed by arranging BF3 counters in multiple concentric rings in a cylindrical paraffin moderator. The sensitivity is flat within ±5% for neutrons between 50 keV and 700 KeV. The absolute efficiency is 2.24% for 50 to 700 keV neutrons and 1.76 % for RaD–Be neutrons in the standard counter arrangement. This efficiency can be increased by mounting more BF3 counters but the relation is not linear because of the mutual interference effect in BF3 counters. The dependence of the counting efficiency on the angular distribution of neutron source was investigated by measurements of thermal neutron distributions in the moderator, and it has proved to be quite small (<1.5%) even for the T3(p, n) He3 reaction in its threshold region.
An Automatic Recorder of the Spark Chamber
Authors: Fukui Shuji , Hayakawa Satio , Kajikawa Ryoichi , Kikuchi Ken , Mori Kunikazu
Published: November 2005

An automatic digitizing-recording system of the spark chamber by means of television vidicon cameras is constructed. It is possible to record two spark columns in one gap simultaneously, and two cameras are used to define the position of a spark column.
One picture is decomposed into 200 horizontal sweep lines in one vertical sweep; among them 40 sweeps are arbitrarily selected for the digitization according to the structure of the chamber.
The digitization area (67% of the sweep length) is divided into 1000 scales and the position of the spark is represented by the 3 digital numbers. The capacity of the memory is just enough to memorize a set of stereoscopic pictures of an event.
At present, the position of the spark is determined with an error of scale 2, the resolving power of two lines is about scale 7 and the linearity between the geometrical position and the digitized result is good.
Messung der zwischen Schi und Fuß spielenden Kräfte
Authors: Ohnishi Tsuyoshi
Published: November 2005

Forces acting between ski and ski-boot were recorded by newly devised measuring apparatuses. In various types of ski-turns, body-forms of skier skiing with such apparatuses were cinematographed. Force measurements were synchronyzed with cinematograph by time signals which were sent to the skier by radio. Relation between such forces and the changes of body-form of the skier were studied.
Die Temperatur aktivierter Teilchen bei der Verbrennung
Authors: Terao Kunio
Published: November 2005

The electron temperature of a propagating flame of an n-Hexane-air mixture was measured using the double probe method. The observed electron temperature showed two peaks nearly at 10,000°K∼15,000°K. Assuming that the electron temperature in the flame front should be in equilibrium with that of the activated particles in the burning process, the activation energy of the chemical reaction of n-Hexane-air was calculated, and the following value was obtained, E=30∼45 Kcal/mol.
Piezoelectric Ceramics of Pb(Zr–Ti)O3 Modified by A1+B5+O3 or A3+B3+O3
Authors: Ikeda Takuro , Okano Tatsuya
Published: November 2005

The properties of the solid solutions (Pb1-x
–A
x
)((Zr
y
–Ti1-y
)1-x
–B
x
)O3 or (1-x)Pb(Zr
y
–Ti1-y
)O3–xABO3 are studied, where A is a mono- or trivalent ion and B a penta- or trivalent ion as follows: A1+=K, Na, B5+=Sb, Nb, Bi; A3+=Bi, La, B3+=Fe, Al, Cr. The composition ranges examined are mostly within x<0.2 and 0.4<y<0.7. With the present method of preparation by the solid state reaction, the soluble range lies mostly within about ten mole percent substitution, but in some cases, for example, for the combination of Bi–Fe or Na–Nb, it spreads much wider. The effects of B ion on the falling of the Curie point and on the shift of the boundary between the tetragonal and rhombohedral phases are discussed. The piezoelectric performances of Pb(Zr–Ti)O3 ceramics are improved by the present modification with ABO3; that is, the dielectric constant increases and the electromechanical coupling coefficient first increases to a broad maximum and then decreases. The coupling coefficient over 0.5 is easily obtained even for less dense ceramics, especially in the case of NaNbO3 substitution.
Decay of Switching Current in Switching of BaTiO3 Crystal due to a-Domain Formation
Authors: Hayashi Mitsuhiko , Imaizumi Shigeo , Abe Ryuji
Published: November 2005

BaTiO3 single crystals are found to be fatigued through formation of many thin a-domains by repetitive switching at applied flelds from 3 to 6 kV/cm. The thickness of the a-domains is of the order of 10-4cm. The origin of the a-domain formation is heat generation by switching and the consequent strains in the crystal. The fatigue increases with increasing switching frequency and with increasing temperature of the crystal. This is explained by the heat generation together with the way the tetragonal deformation of the crystal depends on temperature. Decrease in switched charge is approximately 40% of the initial amount for 10kc/s at room temperature. Details of switching current pulses suggest that there are residual opposite domains to which the most part of the switching current in early stages is attributed and that wall motion is almost completely hindered by the a-domains formed.
Imperfections in Silicon Induced by Diffusion of the Impurities
Authors: Ino Hiroyuki , Kawamura Toyosaku , Yasufuku Matami
Published: November 2005

The fact is shown by means of the chemical etching methods, that the imperfections occur in the peripheries of the diffusion portions in case the selective diffusion of a high concentration of boron or phosphorus is carried out in the silicon single crystal. It was found that in the case of boron, the imperfections occur when the surface concentration is 5×1019 cm-3 and the depth is more than 3µ, and in the case of phosphorus 1×1020 cm-3, more than 3µ respectively. The same method has been applied to the double diffusion. In this case the imperfections were observed around the diffusion portions when the selective diffusion of a high concentration of the phosphorus was carried out while the surface concentration of the boron is less than 5×1019 cm-3. However the imperfection was not observed when that of boron becomes more than 5×1019 cm-3. It is necessary to consider the imperfections caused by the emitter diffusion on transistors.
Decay Rates of Metastable Helium Atoms and Laser Enhancements in Afterglow Period
Authors: Suzuki Norihito
Published: November 2005

The decay rates of the singlet and the triplet metastable atoms of helium and those of the helium-neon mixture are measured by an absorption method. The absorption tube is excited by the pulsed r.f. which is the same as the pulse operation of the laser.
The afterglow of the neon line corresponding to the 2p4–1s4 transition is measured simultaneously. From the decay of the triplet metastable helium atoms and the decay of neon line in the afterglow, the enhancement of the 1.153µ laser oscillation in the afterglow period is investigated. Because the decay of the singlet metastable helium atoms is faster than that of the triplet metastable helium atoms, the visible laser oscillation at 6328Å is not enhanced in the afterglow period.
A New Type of Oscillations in Germanium under the Magnetic Field
Authors: Komatsubara Kiichi , Takasugi Noboru , Kurono Hirokazu
Published: November 2005

A negative resistance characteristics is observed in compensated germanium at liquid helium temperature. The sustaining field strength is changed by the transverse magnetic field. A new type of oscillation phenomenon is observed at the sustaining region when a magnetic field over a critical value is applied.
Samples were prepared from highly compensated germanium single crystal and shaped in a form of rectangular bars. The oscillation frequency, w, is dependent on the crystal orientation with respect to the magnetic field and the current directions. The empirical formula relating the oscillation frequency to the cross section of a sample, L
2, a magnetic field strength, H, and a majority impurity concentration, N

m
, is given by

ω∝\frac{N{_{m}}^{1/3}H}{L^{2}}∼\frac{H}{r_{m}L^{2}}

where r

m
is the mean separation of a majority impurity atoms.
PEM Effect in Silicon
Authors: Ishigame Mareo
Published: November 2005

The PEM effect in silicon was observed by using two p-type specimens doped with boron, which have the charge carrier concentration of 1.96×1013and 3.66×1013cm-3respectively, at 300°K. From the variation with illumination and with temperature, it was found that the energy gap of the recombination center was about 0.35 eV. The spectral dependence of the PEM effect together with that of the photoconductive effect indicated that the diffusion process controlled by the concentration gradient was effective in PEM effect.
The Effect of Squeezing on the Phase Transformation and Magnetic Properties of γ-Fe2O3
Authors: Goto Yasumasa
Published: November 2005

The γ→α phase transformation of Fe2O3 under high pressure and after effects of pressure squeezing upon the magnetic properties of γ-Fe2O3 were studied. The study on the phase transformation was conducted under the pressure up to 3.3×104 kg/cm2 in the temperature range of 150°–300°C. It was found that γ-Fe2O3 has no definite transition temperature even at high pressure and the rate of the transformation increases remarkably with increasing pressure. The rate constant depends principally on the thermodynamic parameter P
Δ
V, where Δ
V is the volume difference between γ and α-forms. Two notable phenomena were also found after pressure squeezing; the saturation magnetization is reduced about 7%, and γ-Fe2O3 becomes more unstable, i.e. it transforms at lower temperature compared with virgin specimen. The two phenomena were explained on the basis of the structure of stacking faults caused by plastic deformation during squeezing.
Isotope Effect on Fragmentation and Kinetic Energy of Fragment Ions from Carbon Dioxide Produced by Electron Impact
Authors: Inoue Miyako , Watanabe Tsutomu , Danno Akibumi
Published: November 2005

To clarify the discrepancy between the values of the isotope effect on C+ ion formation obtained by using magnetic-field scanning and electric-field scanning type mass spectrometers, the errors resulting from the electric field scanning are estimated. Isotope effect on the formation of the C+ ions from carbon dioxide produced by electron impact is measured as a function of electron impact voltage. The effect on the C+ ion yield, defined as the ratio [(13C+)/(12C+)]/[(13CO2
+)/(12CO2
+)] where the parenthesis means the peak height of each ion, is determined as 1.008±0.0015 at 70 V. of electron impact voltage. The kinetic energy of the C+ ions is measured by the discrimination method and is about 0.9 eV. Based on the results of isotope effect and kinetic energy measurements, the dissociation processes from the parent ion to C+ ion are discussed.
Liquid Flow Neutron Monitor
Authors: Okabe Shigeru , Fukuda Kyue , Azuma Toshio , Kurosu Tatsuo
Published: November 2005

A method for continuous monitoring of thermal neutron flux was developed using short lived activities produced by (n, γ) reactions in a circulated liquid solution. It was tested satisfactorily for the neutron flux ranging from 106 to 108 n/cm2/sec produced either by the electron linac of ORC or by the atomic pile of JAERI. Used solutions were Rh2(SO4)3, In(NO3)3 and AgNO3.
Magnetic Properties of Cobalt-Substituted Ni–Zn Ferrites
Authors: Mizushima Masahiro
Published: November 2005

The imaginary part µ'' of the complex magnetic permeability \hatµ (\hatµ=µ'-jµ'') was found to be linearly related to the real part µ' for cobalt-substituted ferrites with the same composition which were annealed at 280°C for various kinds of hours. This fact is explained by assuming that the imaginary part is associated with wall displacement and the contribution of this process to µ' is related to the value of induced anisotropy which is different among specimens heat-treated differently. Two peaks of the imaginary part µ'' were observed in magnetic spectra for the AC demagnetized specimens. The low frequency peak is ascribed to the resonance of domain walls which were displaced from their stable positions. Abrupt increase of the imaginary part µ'' and disappearance of constricted loops were observed at low temperatures, which are explained in terms of the change in sign of the cubic crystalline anisotropy constant K
1.
X-ray Topographic Study on Stacking Faults in Silicon Single Crystals
Authors: Yoshimatsu Mitsuru
Published: November 2005

Various types of stacking faults are studied in more detail. Boundaries of stacking faults are concluded to be partial dislocations of the Shockley type. Stacking faults introduced by splitting of total dislocations into partial dislocations are also observed. By comparative studies of X-ray image with optical ones of the etched surface, it is found that some stacking faults consist of multi-planes of different dimensions.
Dielectric Relaxations in Polyoxymethylene and Polyethylene Oxide
Authors: Arisawa Kunio , Tsuge Kenji , Wada Yasaku
Published: November 2005

Dielectric properties in the frequency range 10-1 to 106 c/s are studied above 100°C for polyoxymethylene (POM) and above -32°C for polyethylene oxide (PEO). In case of POM, a dielectric dispersion which corresponds to the mechanical α dispersion in its frequency and temperature position is observed and is assigned to the crystalline phase. The relaxation strength Δ
ε of this dispersion increases with increasing crystallinity and, when compared at a constant crystallinity, Δ
ε is larger and the relaxation time is longer for the sample of larger lamella thickness. This behavior follows qualitatively the prediction of Okano's theory of the crystalline dispersion. The magnitude of Δ
ε, however, is larger than the theoretical one by the order of three. Several possible origins of this discrepancy are suggested. In case of PEO, the primary dispersion which comes from segmental motion in the amorphous phase is observed. The relaxation strength of the dispersion agrees well with theory. Dispersion maps of the two polymers compiled from existing literatures as well as the present study are presented.
The Decay in Electrical Resistance in Evaporated Gold Films
Authors: Kinbara Akira , Sawatari Yuji
Published: November 2005

The irreversible changes in electrical resistance (time-decay) of gold films evaporated at room temperature were measured as a function of time to know the mechanism of the forming process of evaporated films. An experimental formula was derived for the change in electrical resistance. For the initial portions of the decay curves, the decay ratedR/dtwas found to be proportional to (R-R∞)n, wherenwas almost independent of the evaporation rate. When the film thickness is 140 A±10 A,nis about 6.0 and it increases with increasing thickness. The mechanism of decay is understood as annihilation process of distortions generated in films during deposition. It is found that recombination theory and diffusion theory already proposed to explain the phenomenon are unsuitable to interprete the decay of the very initial stage of the film formation. It seems that much more complicated processes take place at this stage.
Vapor Reaction Growth of SnO2 Single Crystals and Their Properties
Authors: Nagasawa Masahiro , Shionoya Shigeo , Makishima Shoji
Published: November 2005

In order to obtain single crystals of SnO2 which can be used for the investigation of the intrinsic electrical and other related properties, crystal growth by the method using the vapor reaction of SnCl4 with H2O was attempted, and was successfully performed. Colorless transparent single crystals with sizes up to 2×5×15 mm could be obtained by 24 hr run at 1300°C. The measurements of crystallographic properties, optical transmission, electrical conductivity and Hall effect were carried out with the grown single crystals. The crystals were found to be twins having {011} twinning plane. It was shown that the crystal is a typical n-type broad-band semiconductor having the value of the conductivity of a few Ω-1·cm-1 and the mobility of about 200 cm2·volt-1·sec-1 at room temperature. The mobility of the crystals was found to change by the equation µ∝T
-2 above 250°K.
Internal Stress of Evaporated Thin Gold Films
Authors: Kinbara Akira , Haraki Hiroshi
Published: November 2005

The character of a planar tensile stress (observed) in evaporated gold films has been investigated by means of bending method and X-ray diffraction. It has been found that stress increases with increasing film thickness in films thinner than 1000 Å and approaches to a certain values of the order of 109 dyn/cm2 in thicker films. By annealing, the bending of the substrate increases, showing the increase of the stress in films but the X-ray diffraction shows that the stress in crystal grains in films decreases.
Switching Transient in NaNO2
Authors: Hatta Ichiro , Sawada Shozo
Published: November 2005

The switching transient in NaNO2was observed in a temperature range between about 100°C and the Curie temperature and in an applied electric field range up to 7 kv/cm. The shape of the switching transient depended remarkably on temperature; in the immediate neighborhood of the Curie temperature it was asymmetric, and it approached to a symmetric one as temperature decreased. Judged by Fatuzzo's theoretical consideration, the nucleation density would increase abruptly in the neighborhood of the Curie temperature and in the low temperature region the sidewise motion of the domain wall would be predominant. The field dependence of the switching transient showed only a slight change.
Evaluation of Surface State at Oxidized Silicon from the Characteristics of Surface Varactor Diode
Authors: Horiuchi Shiro , Yamaguchi Jiro , Shibata Keizo
Published: November 2005

Surface state at the interface of silicon and oxidized silicon are studied by observing the capacitance-voltage characteristic of silicon surface varactor diodes. Typical value of the trap density is 1×1011cm-2 at 0.24 eV above the center of band gap and 4×1011cm-2 at the center of band gap. Validity of the procedure for obtaining the state density from varactor characteristics is also considered briefly.
A Ruby Laser with External Mirrors of Large Spacing
Authors: Shimizu Tadao , Shimizu Fujio , Kawaguti Minato , Shimoda Koichi
Published: November 2005

Characteristics of a ruby laser are studied when the separation between mirrors of the resonator is as long as 10.5 m and 24.5 m. The experiments performed are: (1) the observation of beat signals between axial modes by an oscilloscope, and (2) Fabry-Perot analysis of the spectrum. Relation between the two results is discussed. Mode selection effect due to the characteristics of its double resonator is found.
Oscillation Modes of Oscillistors I Uniform Magnetic Field.
Authors: Arizumi Tetsuya , Umeno Masayoshi
Published: November 2005

In order to investigate the dominant mode in the oscillistor oscillation, the density oscillations of m=0 and helical modes have been studied by observing simultaneously both the transmitted microwave signal through a sample whose diameter was smaller than the skin depth and the potential difference between two probes alloyed axial-symmetrically on the sample.
Experiments showed the following results: (1) The m=0 mode oscillation of plasma density is predominant in oscillistor oscillation, and (2) the helical mode oscillation is excited at larger magnetic field or current than that of the m=0 mode oscillation. (3) The terminal voltage oscillation is equivalent to the m=0 mode oscillation. (4) The oscillation is excited only in a limited region 2–4 mm from the injecting junction, and this density oscillation travels along the drift direction of the minority carriers. (5) The drift velocity of the density wave increases with the distance from the exciting position.
On the Design of the Vacuum System of Tokyo Electron Synchrotron
Authors: Horikoshi Gen'ichi
Published: November 2005

Design and operation of the vacuum system of the electron synchrotron at the Institute for Nuclear Study, University of Tokyo are described. The number of pumps to be installed around the donut ring of the electron synchrotron was determined by a quantitative estimation based on experimental data. Eight pumping units are installed around the donut ring. These units are all linked at the backside, and are backed by one fore-pump system consisting of an oil diffusion pump and a rotary pump. The role of the diffusion pump in the fore-pump system is discussed with results of pressure distribution measurement in the vacuum system under various conditions. Each pump unit used in the vacuum system of the synchrotron is operated without any cold trap.
Direct Observation of the Multiplication of Dislocations in a Thin Foil of an Aluminium-Silver Alloy
Authors: Nemoto Minoru , Koda Shigeyasu
Published: November 2005

The transmission electron microscopic investigation of the thin foil of an aluminium-silver alloy has revealed the operation of a spiral type of Frank-Read source induced by high-intensity and fine-focus illumination. A part of a dislocation whose Burgers vector lies in the slip plane has rotated around the point of emergence of the other part of the dislocation not lying in the same slip plane. It has been observed that the source has emitted at least seven dislocation loops in the life time. The nature of the dislocation has been defined from the cross slip traces. The thickness of the foil has also been estimated, from the width of the slip traces and the surface orientation, at about 5700 Å.
Non-Ohmic Conduction in Vacuum-Deposited SiO Films
Authors: Hirose Hidenori , Wada Yasaku
Published: November 2005

The current through vacuum-deposited SiO films in the thickness range 1–4 µ is measured as a function of voltage and temperature between 10° and 80°C. Three regions are distinguished in the current-voltage relationship; (1) voltage below 0.1 V, (2) from 0.1 to 10 V and (3) above 10 V. The current-voltage characteristic is linear in the region (1) but becomes nonlinear in the regions (2) and (3). In the region (3), the current depends on voltage and thickness only through the electric field E, the activation energy decreases linearly with increasing E
1/2 and the logarithmic current increases linearly with increasing E
1/2. These results are quantitatively explained in terms of field enhanced thermal excitation of trapped electrons into the conduction band (Poole-Frenkel effect). The energy gap between trap level and conduction band is estimated to be 0.54 eV.
X-Ray Micrographic Study of Silicon Carbide Crystals
Authors: Ohta Kiyoshi , Tomita Takanori , Watanabe Tamaki
Published: November 2005

The traverse X-ray diffraction micrography is applied to studies on silicon carbide single crystals of 6H structure. Two kinds of dislocations of new types, having the Burgers vector in a <11̄00> direction and in an average direction <33̄02>, are found. The second kind of dislocation is often found in distorted regions of the crystals and sometimes created by chopping or neutron irradiation. Impurity layers which are proved to exist seem to be a cause of the lattice distortion. The mechanism of crystal growth is discussed in relation to the second kind of dislocation.
Growth of Copper Whiskers from Cupric Oxide
Authors: Kittaka Shigeyoshi , Kishi Kiyoshi
Published: November 2005

A great number of copper whiskers of the order of 109 have been grown in a single run when CuO is reduced in CO-CO2-N2 atmosphere with the addition of small amounts of CuCl and graphite. The whiskers grow on the surface of the graphite particles mostly in length of 0.1∼1.5 mm, in some cases as long as 15 mm, their diameter being between 0.5 and 3µ and fairly uniform for a single run. Some interesting forms of whiskers are observed. The fundamental properties of the whiskers thus obtained are nearly the same as those formed by the known method of hydrogen reduction of copper halides.
Resonance of Phase Oscillations in a Synchrotron
Authors: Kawasaki Sunao
Published: November 2005

A possibility that accelerated electrons in a synchrotron escape beyond the region of stability in their phase oscillations owing to fluctuations of operating parameters of the machine was calculated. The results predicts that the non-linearity of the oscillations has the most important role in this problem, especially in AG machine, and that there are resonance between the oscillations and the fluctuations when the frequency of fluctuations takes a value of 0.6∼0.7 times that of the phase oscillations, as a principal mode with a rather wide frequency spread. The analyses were compared with the results of the experiments in which the external perturbations were imposed on the amplitude of the accelerating RF voltage in Todai 170 MeV AGS. Their consistence was rather good.
Similarity Principle and Its Application to a High Frequency Gas Discharge Multiplier
Authors: Chiyoda Katsuji
Published: November 2005

On the basis of the Boltzmann equation, the similarity principle is slightly extended after the method of H. Margenau. In terms of the results a basic idea for the design of a frequency multiplier using a gaseous discharge is proposed. The theory is briefly compared with experimental results.
Switching Characteristics of Composite Magnetic Thin Films
Authors: Goto Eiichi , Hayashi Nobuo , Honma Noriyuki , Kuroda Ryo , Miyashita Takaaki
Published: November 2005

The effects of the strong exchange coupling between magnetic spins within a composite film, composed of multiple layers of ferromagnetics, are represented by biaxial and triaxial anisotropy terms to be added to the ordinary effective magnetic energy. The influences of these multiaxial terms on the form of the critical switching curves are studied theoretically and experimentally. An experimental result is given showing a considerable improvement of the pulse coincidence switching characteristic of an ordinary uniaxially anisotropic permalloy film by adding a very thin Ni-Co alloy layer thereupon.
Superficial Plastic Deformation due to Surface Finishing Pevealed by Preferential Precipitation in an Aluminium 25 Per Cent Silver Alloy
Authors: Takahashi Noboru , Kosuge Hiroko
Published: November 2005

The surface of Al-25% Ag alloy, solution treated at 570°C for 3 hr and water-quenched, have been ground by various mechanical operations of surface finishing and aged at 150°C for 5 hr and at 300°C for 1 hr respectively, leading to the formation of two kinds of precipitate particles, i.e. G. P. zones and a Widmanastätten structure, respectively. The nature and distribution of precipitate particles thus formed in the surface layers were examined by replica method of electron microscopy. Observations normal and oblique to the surface layers were carried out for the purpose of studying the gradual change of precipitate particles.
Scratches are decorated by two kinds of precipitate particles. It is noted that the form of the precipitate particles is different on the side and the bottom of a groove produced by finishing, leading to the conclusion that shearing stresses act principally on the side of the groove, while compressive stresses are predominant on the bottom of it. In the latter case, a normal Widmanstätten structure does not develop, but granular particles are found.
Precipitation of Cu-Be Compounds from a Supersaturated Solid Solution of the Cu-2% Be Alloy
Authors: Nakagawa Masayuki
Published: November 2005

The precipitation of Cu–Be compounds from a supersaturated solid solution of the copper-2 percent beryllium alloy by ageing at a temperature lower than 400°C was studied with a transmission electron microscope and by the X-ray diffraction method. The structures of precipitates, their orientation relationship, and the effects of dislocations, and grain boundaries on the precipitation process were investigated. The change of lattice constant of the alloy aged under various conditions was examined by the X-ray diffraction method, and the ageing conditions for different kinds of precipitate were determined.
Plastic Deformation of Pd-H Alloys
Authors: Takagi Seizo , Sugeno Takesi
Published: November 2005

Tensile tests at various temperatures and strain rates have been carried out on palladium-hydrogen alloys. Hardening in the α-phase alloys has been measured over the temperature range -78 to +130°C and the result was explained by the chemical interaction between dislocations and solute atoms. Existence of Cottrell effect in the alloy was not evident enough for the hardening to be explained. At liquid nitrogen temperature the Portevin-LeChatelier phenomena were observed. These phenomena were not explained by the strain aging mechanism. Some other interesting results are also reported.
Information Volumes of Radiographs Modified by Sharpness and Visual Effects
Authors: Kanamori Hitoshi
Published: November 2005

Information volume due to contrast in an image (macroscopic characteristics) defied in a previous paper is first modified by sharpness (microscopic characteristics). Instead of normal contrasts, contrasts in images of a slit with a fixed width, as well as frequency responses at a fixed spatial frequency, were utilized. Because of unsharpness, sharpness information is usually less than contrast information. This situation, however, reverses when the edge effect is noticeable. Secondly, information volume is modified by minimum perceptible contrasts. It also takes a maximum with proper quality and quantity of radiation.
Cosmic-Ray Contribution to the Background of NaI Scintillation Spectrometers
Authors: Tanaka Eiichi , Itoh Susumu , Hiramoto Toshiyuki , Iinuma Takeshi A.
Published: November 2005

The cosmic-ray contribution to the background of a 3-in. by 3-in. NaI detector in an iron room has been studied by coincidence technique with a 4π plastic scintillator covering former detector. The NaI detector was surrounded by various material inside the 4π guard detector in order to find the effect of the surrounding material.
The observed counting rate due to the cosmic-ray component was about 19% of the total background in 0.1–0.4 MeV and 31% in 0.6–0.9 MeV when the NaI detector was surrounded by 5 cm lead. The cosmic-ray contribution did not critically depend upon the atomic number of the surroundings in the energy of 0.6–0.9 MeV and in the annihilation peak but it decreased rapidly with increasing atomic number in 0.1–0.4 MeV.
Photoconduction du Sulfo-Séléniure de Cadmium en Couche Evaporée
Authors: Asano Sumitada , Yamashita Nobuhiko
Published: November 2005

Some films of the solid solution Cd(S:Se) are prepared by vacuum evaporation. When the temperature of the glass plate or quartz plate used as a support is raised regularly from 300° to 600°C with increasing CdSe proportion, films with nearly constant hexagonality of about 80% are obtained. The c-axis of hexagonal cristallites is oriented perpendicularly to the plane of film. The spectroscopic studies and the measurements on thermally excited current and temperature dependence of photo-current yield show that some deep hole traps and shallow ones are formed in addition to deep electron traps and shallow ones. The ionization energies of these electron and hole traps as well as the band gap are regularly reduced with CdSe proportion. The experimental results are compared with those obtained previously for Cd(S:Se) Single crystals and some remarkable differences are found.
Preparation of Ge-GaAs Heterojunctions by Vacuum Evaporation
Authors: Ryu In-Soun , Takahashi Kiyoshi
Published: November 2005

Heterojunctions have been made by depositing Ge epitaxially on GaAs substrate by vacuum evaporation. The crystalline structures are examined by electron diffraction. Some electrical and photoelectrical characteristics are investigated, which are well consistent with those prepared by vapor growth. The good characteristics of heterojunction can be obtained at substrate tempepatures in the vicinity of 800°C.
Temperature and Bias Characteristics of Pb(Zr-Ti)O3 Families Ceramics
Authors: Uchida Naoya , Ikeda Takuro
Published: November 2005

Temperature and bias characteristics of ceramics of Pb(Zr-Ti)O3 and its families have been measured. Bias dependence can be understood with a schematic model on the reorientations of 180° and 90° domains. Dielectric and elastic anisotropies of the single crystal are expected to be larger in the rhombohedral phase than in the tetragonal one. Temperature dependence under fixed biases have led to a supposition that ε
11 and s
11 are more temperature dependent than ε
33 and s
33, respectively. Physical constants of ceramics are not single-valued functions of polarization P
*. This fact will support Marutake's criticism on the thermodynamic treatments of ceramics formerly reported. A trial of dividing P
* into the increment P
180
* caused by 180°-reversals and that P
90
* by 90°-rotations make it possible to understand behaviors of piezoelectric constants d
31
*, g
31
* and coupling coefficient k

r

*
versus
P
*. Constants d
31
* and k

r

* do not represent the degree of poling, and g
31
* will be recommended as its practical measure.
Oxygen Effect and Temperature Dependence of Fluorescence Intensity in Naphthalene Scintillators
Authors: Kobayashi Shigeo , Hayakawa Sohachiro
Published: November 2005

In solution scintillators with molten naphthalene as a solvent, fluorescence quenching by dissolved oxygen and the temperature dependence of light output are studied with excitation by gamma-rays and uv lights. The fluorescent solutes are PPO, BBO, POPOP, QP, DPH and DPS. Dissolved oxygen can be removed rapidly by bubbling nitrogen. Quenching by oxygen is shown to be in competition with energy transfer from solvent to solute. It may be estimated that the lifetime of excited molecules in molten pure naphthalene is increased to almost twice by removal of oxygen. The bubbling of nitrogen increases the fluorescence intensities of practical solutions by 20–40%. The negative temperature coefficients of light output of naphthalene solutions are 2–7×10-3/°C independent of excitation modes. The fluorescence intensities of the solutions equilibrated with air remain almost constant over the temperature range of 80–130°C.
Quenched-in Vacancies in Zone-Refined Aluminum
Authors: Kabemoto Satoru
Published: November 2005

The decay curves of quenched-in resistivity in zone-refined aluminum have been analyzed in detail to estimate the basic data of quenched-in vacancies. The results are as follows.
The formation energy of a single vacancy is 0.77±0.02 eV. The vacancy resistivity per unit concentration at room temperature is (2.5±0.8)×10-4Ωcm, the activation energy of self-diffusion evaluated from the apparent activation energy in the second annealing stage is 1.48±0.02 eV, the migration energies of a single vacancy and a divacancy are 0.71±0.04 eV and 0.55±0.03 eV, respectively, and the binding energy of a divacancy is 0.18±0.03 eV.
Finally, brief discussion is made on the vacancy sinks formed during ageing from the number of jumps necessary for a single vacancy or a divacancy to reach sinks.
The Activation Energy for Oxygen Desorption from Zinc Oxide Surfaces
Authors: Watanabe Hideo , Wada Masanobu , Takahashi Tadashi
Published: November 2005

The presence of adsorbed oxygen decreases the electronic conductivity of zinc oxide powder. The rate of desorption of oxygen increases with temperature. The resulting deta yield an activation energy of 1.0 to 1.1 eV for the oxygen desorption. It is shown that this is the binding energy for the chemically adsorbed oxygen.
Effect of Orientation on Surface Charge Density at Silicon-Silicon Dioxide Interface
Authors: Miura Yoshio
Published: November 2005

The effect of the orientation of the silicon substrate on the surface charge density, N

F
B
, at the silicon-silicon dioxide interface is studied. Surface oxidation of silicon is carried out at 1140°C in dry oxygen. The surface charge density is determined from the capacitance-voltage characteristics of the MOS diode. Measurements are made at 1 Mc/sec small singnal superposed on a dc bias. The orientation of silicon has a remarkable influence on N

F
B
, and its magnitude becomes smaller in the order of (111), (211), (110), and (100) planes. In the case of (100) silicon substrate, the depletion of electrons at the silicon-silicon dioxide interface is observed.
X-Ray Observations of Defect Structures in Silicon Crystals
Authors: Sugita Yoshimitsu
Published: November 2005

The structure of defects in silicon crystals, which causes X-ray double images, was studied in detail by the X-ray diffraction topography and the etching technique. Generation of these defects was found to be closely related to growing conditions of the crystal, particularly to the condition of hydrogen gas flow used as an ambient. A pair of parallel etch pit arrays was observed on an etched surface and was confirmed to have one-to-one correspondence to the double image. When a specimen was annealed in the range from 700°C to 1000°C, the double image showed fine structures, which could be only observed by using softer radiation, CuKα1. Two types of dislocation loops were generated from the defect corresponding to the double image when a specimen was annealed at 1200°C. The origin and the mechanism of formation of the defect was discussed.
Non-Glare Headlight with a Sodium Nitrate Polarizer as a Filter
Authors: Yamaguti Tasaburô
Published: November 2005

With a view of obtaining a polarization headlight which is sufficiently bright for a free field driving and at the same time is dim to a driver of an oncoming vehicle who views the headlight through an analyser placed in the crossed position to the polarizer over this headlight, a set of polarization headlight system is constructed. It consists of a sealed beam headlamp with a smooth front cover glass, having the same 50 watt filament as the conventional sealed beam one, a cylindrical lens system over a part of the aperture and a sodium nitrate polarization plate. Illuminance of this set satisfies the Japanese Industrial Standard (JIS), which is equivalent to the SAE in America. Its maximum light intensity, 26200 Cd, is about 2.7 times as high as that of the known type of polarization headlight (9800 Cd) with the use of “Dichrom” or “Polaroid”, and is about 86 per cent of 30600 Cd of the conventional sealed beam headlight.
Preparation and Electrical Properties of Polytetracyano-ethylene Copper Chelate Film
Authors: Naraba Tsunezo , Mizushima Yoshihiko , Noake Haruo , Imamura Akira , Igarashi Yoshitaka , Torihashi Yoshikazu , Nishioka Atsuo
Published: November 2005

The preparation and physical properties of polytetracyano-ethylene (TCNE) copper chelate film were studied. The reaction of TCNE with copper consists of the first rapid and the second slow processes. An optimized condition for the preparation was to heat for 9 to 24 hours at 400°C. Element analysis of carbon and copper, and electron probe microanalysis revealed nonuniform distribution of copper atoms across the film, about 30 % near the surface based on the copper plate and 20 % on the opposite side. The electrical conductivity shows a remarkable anisotropic effect in both directions of perpendicular and along the base side, with activation energy of 0.1 to 0.5 eV, and the highest conductivity of 10-1 mho.cm-1. Heat treatment changes the distribution of copper, free radical concentration, electrical conductivity, and dielectric properties of the film. Nonohmic conduction appears on the perpendicular direction and was interpreted as space-charge-limited mechanism. The excess copper atoms over the chelate composition (TCNE: Cu=2:1) may contribute to the high conductivity on the base surface and dielectric properties.
Treeing in Solid Insulator
Authors: Toriyama Yotsuo , Mitsui Hideo
Published: November 2005

The mechanism of dendritic growth of discharge, or “Treeing” in solid insulator was investigated and the following conclusions were obtained. In the first stage of “Treeing”, there occurs pure electronic breakdown due to ionization by collision of electrons. In the second stage rupture of chemical bonds by electron collision occurs. Then the processes produce molecules of lower molecular weight or gas phase. The existence of these processes were confirmed in consequence of the growth of bubbles from “Treeing” by heating Plexiglas immediately after the occurrence of “Treeing” up to a temperature near its softening point.
Ion Cyclotron Instabilities in a Bounded Beam-Plasma System
Authors: Hasegawa Akira
Published: November 2005

Ion cyclotron instabilities in a bounded cold beam-plasma system are considered, with an electron beam injected parallel to an applied uniform magnetic field. The conditions and the growth rates of the instabilities of both of the electromagnetic and the electrostatic ion cyclotron waves due to their interactions with the electron beam are obtained. The surface current created by an azimuthal dc spinning times the radial ac displacement of the beam is found to have a significant role on the electromagnetic growth rate, while the presence of warm plasma electrons is found to be essential for the electrostatic instability. It is shown that if the direction of the dc spinning of the beam is in the same sense as that of the plasma ion gyration, the electromagnetic instability is remarkably enhanced.
Dependences of Output Powers on the Discharge Current in Single-Line and Two-Line Oscillations of He-Ne Lasers
Authors: Asami Shigeo
Published: November 2005

A general method of expressing the output powers of gaseous lasers on a single line or simultaneous oscillations on two lines as a function of pumping rates and transition probabilities is developed from the standpoint of an electronic network analog of the rate equations. By application of this method to the 1.15 µ, 6328 Å, and 3.39 µ lines of He-Ne lasers, the dependences of their powers on the discharge current are discussed and found to be in agreement with experimental results. Furthermore, example of simultaneous oscillations of the 1.15 µ and 6328 Å lines as well as those of the 6328 Å and 3.39 µ lines are treated, giving results which are also in agreement with experimental results. Features of the dependences of the output powers on the discharge current in the simultaneous oscillations are stated in connection with those in the single-line oscillations.
Transient Behavior of He-Ne Lasers
Authors: Ohi Misao
Published: November 2005

An experimental study on He-Ne laser (1.15 µ) under pulsed H.F. excitation reveals that there exist delay in oscillation build-up and a peak in the output at the beginning of oscillation. From qualitative discussions on the behavior of photon density and inversion density on the basis of coupled rate equations, these transient phenomena are shown reasonable. Contributions of various factors related to lasing mechanism are clarified from numerical calculations of simplified rate equations by the use of electronic computers. Both loss terms for the photon and the inversion effect strongly the shape of the curve of the solution. The increase of the former produces an oscillating build-up, while the contribution of the latter is opposite. Resultant contribution of the loss terms is also analysed. A reasonable set of the coefficients is found to lead to a solution having the delay which agrees with the experiment.
Mn-Zn-Ferrites with Low Loss Property and High Initial Permeability
Authors: Hirota Eiichi
Published: November 2005

The effects of the addition of CaO and GeO2 in iron excess Mn-Zn-ferrites were investigated for improving the high frequency loss property. The µ·Q value of 8×104 with µ of 700 at 1 Mc/s was obtained. The low loss property is attributed to its high resistivity caused by the addition of CaO and GeO2, followed by the domain wall stabilization by an induced anisotropy.
Optimum Design of Elliptical Pumping Chambers for Solid Lasers
Authors: Kamiryo Kozo , Kano Tetsuo , Matsuzawa Hidenori
Published: November 2005

Fundamental charts for designing optimum elliptical pumping chambers are obtained from numerical calculations which contain all the geometrical sizes of pumping lamps and laser rods and the reflectivity of walls. The coupling efficiency between the lamp and the laser rod is compared with that of cylindrical chambers. When 2a/r

R
\gtrsim72, where 2a is the major axis of ellipse or the diameter of cylinders and r

R
is the radius of laser rod, elliptical chambers are approximated by the cylindrical. The lowest energy for laser action is about 85J in the present experiments with the elliptical chambers whose reflectivity is about 0.7.