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Y. C. Liu, T. H. Hsu, E. K. Lin, P. K. Tseng, C. C. Hsu, C. W. Wang
1975 年 39 巻 1 号 p.
1-6
発行日: 1975/07/15
公開日: 2007/05/29
ジャーナル
認証あり
The
70Ge(p, γ)
71As reaction has been investigated in the energy range from E
p=1.0 to 2.5 MeV. Excitation function was obtained for the reaction over this energy region. High-resolution measurements of the de-excitation γ-rays from this reactions have been made at E
p=2.434 and 2.030 MeV by using a 50 cm
3 Ge(Li) detector. The energy levels of
71As up to 2947 keV excitation and γ-ray branching ratios were determined; several new levels are proposed. The Q value for this reaction was also determined.
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Takeo Fujiwara, Yukito Tanabe
1975 年 39 巻 1 号 p.
7-17
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
General feature of the magnon sideband is investigated taking into account the inter-sublattice exciton transfer and the orbital degeneracy of the exciton state. The results are applied to
4E
g(G) states of RbMnF
3 and MnF
2. The effect of large transfer integral as a possible mechanism responsible for the appearance of exciton-magnon bound state and multi-magnon sideband is proposed and discussed. Fair agreement with experiments for RbMnF
3 is obtained by assuming this mechanism. The observed change in the absorption spectra due to Co impurity of the system KMn
1−xCo
xF
3 is understood by the proposed mechanism.
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Michisuke Kobayashi, Junya Mizuno, Isaaki Yokota
1975 年 39 巻 1 号 p.
18-21
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
The plasma dispersion of a layered electron gas in a magnetic field is calculated in the random phase approximation for the Voigt configuration. We found that the plasmon gradually changes its character from the two-dimensional to the three-dimensional ones as the spacing between the planes of the layer decreases.
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Kimiaki Konno, Heiji Sanuki
1975 年 39 巻 1 号 p.
22-24
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
The Bäcklund transformation for the equation of the motion for the nonlinear lattice under the influence of the weak dislocation potential is discussed. It is found that Bäcklund transformation is derived from Riccati form of inverse method and that a recursion formula to obtain a ladder of kind solutions is constructed. An infinite number of conservation laws is obtained.
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Yoshitsugu Oono
1975 年 39 巻 1 号 p.
25-29
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
For a lattice polymer on the cubic lattice and for a Gaussian polymer in three dimensional space, it is proved that the square of the expansion factor α is zero for negative real
z, the measure of the strength of the intrachain interaction, when the polymer length becomes infinite under the condition that
z is kept finite. This fact implies that the perturbation series for α
2(
z) is not convergent except at
z=0.
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Hiroshi Sato, Susumu Sasaki
1975 年 39 巻 1 号 p.
30-35
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Asymptotic behaviors of the distribution of number of events in a fixed interval of time and of the distribution of interval length between the first and the
N+1 st events of a stationary point process, where N is some fixed number, are discussed and a simple relation between variances of these two distributions is derived from the normality of the two distributions. From this a relation is derived which expresses the number fluctuation in terms of the correlation coefficients between lengths of neighboring intervals. Those behaviors and relations are confirmed by experiments in which the number of events and the length of the time interval are measured by electronic counters directly connected to a computer. Measurements are made for the zero-crossing points of a continuous Gaussian noise.
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Takashi Iwashita, Norikiyo Uryû
1975 年 39 巻 1 号 p.
36-41
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Spin wave analysis has been made on CoCl
2·6H
2O for its antiferromagnetic, spin flop and paramagnetic states when the external magnetic field exists. The temperature and the field dependences of the magnetic susceptibility have been calculated with the exchange constants
J1,
J2 and
J3 estimated by Kimura. The experimental results by Metselaar and De Klerk can be satisfactorily explained by the present calculation. The magnetic phase diagram is also discussed.
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Koichi Katsumata
1975 年 39 巻 1 号 p.
42-49
発行日: 1975/07/15
公開日: 2007/05/29
ジャーナル
認証あり
Magnetization in metamagnetic FeCl
2·2H
2O has been studied in detail under both a pulsed and a static magnetic fields at temperatures between 1.5 K∼14 K. At high temperatures, a transition from the antiferromagnetic (A.F.) to the ferromagnetic (
Ms⁄3) states at
Hc1 and that from the
Ms⁄3 to the ferrimagnetic (
Ms) states at
Hc2 are observed. A large hysteresis has been observed at
Hc1 even under a slowly varying field. As the temperature is lowered, a transition from the A.F. to a
Ms⁄2 states followed by that from the
Ms⁄2 to the
Ms⁄3 states accompanying with that from the
Ms⁄3 to the
Ms states takes place in an increasing field. The
Ms⁄2 state which is a high energy state in this salt becomes stable with decreasing temperature. Below 2.24 K, a large hysteresis at
Hc2 is observed even under a slowly varying field.
It is shown that the main origin of the anomalously large hysteresis comes from the energetic barrier due to a strong single ion anisotropy energy. The appearance of a new phase (
Ms⁄2 state) arises from the fact that a
Ms⁄2 state is constructed by a simple reversal of down spins in the A.F. state, while the
Ms⁄3 state by a complicated rearrangement of up and down spins.
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Tsuyoshi Murao
1975 年 39 巻 1 号 p.
50-57
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Along the same line as in the previous paper, an effective nuclear spin Hamiltonian is derived for the system where magnetic ions have the electronic singlet ground state and are interacting each other by the exchange interaction. All crystal-field levels of electrons are taken into account so that the Hamiltonian can be used for any realistic case in the nuclear regime. The exchange enhancement appears in the form of (1−η)
−1 for the electronic Zeeman energy, the
I–
I coupling, the pseudo nuclear quadrupole interaction, and the pseudo nuclear Zeeman effect, η being proportional to the exchange constant. Examples are shown for rare earth ions and the resulting
I–
I coupling has the form of the Heisenberg model in the cubic case but of the
X–
Y model in the uniaxial case.
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Takashi Iwashita, Norikiyo Uryu
1975 年 39 巻 1 号 p.
58-62
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
The spin wave analysis has been made on an antiferromagnet NiCl
2·6H
2O. With the use of the crystalline field parameters
D and
E, and the exchange constants
J1 and
J2 estimated by Kimura in the paramagnetic region, the temperature dependence of the magnetic susceptibility and the specific heat does not show an agreement with experiment. A good agreement, however, can be obtained with a slightly modified values of
D and
E, and with a slightly large exchange constant.
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Yoshikazu Nishihara, Shinji Ogawa, Shinya Waki
1975 年 39 巻 1 号 p.
63-69
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Mössbauer experiment has been performed of
57Fe doped in antiferromagnetic NiS
2. The supertransferred hyperfine field of 19 kOe has been observed at 4.2 K. From the analysis of the supertransferred hyperfine field, it is concluded that NiS
2 has a non-collinear spin structure. The Ni spins with ordering of the first kind for fcc lattice make a constant angle θ with the principal axis of the electric field gradient at the Ni sites. The angle θ is (12±4)° above 30 K and (21±6)° below 30 K. The component of Ni spin with the first kind ordering varies smoothly through 30 K. No anomaly has been observed in the isomer shift and the quadrupole splitting at 30 K and at Néel temperature of 54 K. The quadrupole splitting is −(0.27±0.01) mm/sec at 295 K. An effect of
u parameter of crystal lattice can explain the negative sign and the weak temperature dependence of the quadrupole splitting of
57Fe in NiS
2.
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Hiroshi Nagasawa, Masayoshi Senba
1975 年 39 巻 1 号 p.
70-75
発行日: 1975/07/15
公開日: 2007/05/29
ジャーナル
認証あり
Resistivity of α-Mn alloys containing dilute V, Cr, Fe, Co, and Ni impurities was measured between 1.6 K and room temperature.
T2-dependence in resistivity was found below 10 K in these alloys. The anomalously large coefficient of
T2-term of 0.125 μΩcm/K
2 in low temperature resistivity of α-Mn was drastically influenced by addition of 1 at% V, Cr, Fe, Co and Ni impurities and the coefficient varies to −0.01, +0.05, +0.06, −0.005 and −0.05 μΩcm/K
2 respectively for transition metal impurities. This
T2 law of resistivity in α-Mn alloys was discussed as the effect of spin fluctuations.
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Taro Toyoda
1975 年 39 巻 1 号 p.
76-83
発行日: 1975/07/15
公開日: 2007/05/29
ジャーナル
認証あり
Resistivities of a series of Au- or Cu-based dilute alloys containing 4
d elements were measured between 1.5 K and 4.2 K in order to investigate the effect of these elements in noble metals. It was found that there was no temperature dependence of the resistivity over the above range on any of the dilute alloys and that the obtained values of residual resistivities were considerably smaller than those for the 3
d elements.
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Naokatsu Sano, Kenji Shimizu, Junkichi Itoh
1975 年 39 巻 1 号 p.
84-92
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
NMR spectra of Tb
159, Dy
163 and Er
167 in various heavy rare earth alloys which are all in magnetically ordered states were investigated at liquid helium temperature, and the values of magnetic dipole and electric quadrupole hyperfine interactions were determined. In these heavy rare earth alloys, the main contribution to the hyperfine interactions arises from the unfilled 4f electrons of the parent ion. But there exist some other minor contributions; the electric quadrupole interaction arising from the lattice and conduction electron charges and the internal field produced by the polarization of the conduction electrons, which are discussed by analysing our experimental results.
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Naokatsu Sano, Kenji Shimizu, Yukio Aoki, Junkichi Itoh
1975 年 39 巻 1 号 p.
93-97
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
The semi-cone angles of Tb and Er in Tb–Er alloys and of Dy and Er in Dy–Er alloys both in conical structure are calculated by analyzing the results of our spin echo measurements on these alloys. It was found that the angles of individual components are different with each other, indicating a double cone structure. A simple molecular field calculation shows that really such double cone structure is the most stable one in these alloys, provided that the exchange and anisotropy constants are properly chosen.
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Masatoshi Sato
1975 年 39 巻 1 号 p.
98-102
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Magnetic properties and electrical resistivity of (Ni
1−xPd
x)
3Al were measured. The value of
x were varied up to 0.20 through the ferromagnetic critical concentration
xc\simeq0.095. The magnetic susceptibility of this alloy series can be explained by the simple uniform enhancement model approximately. The experimental results were discussed by the recent theories developed by Moriya and Kawabata. The qualitative agreement between the experimental result and the theoretical one is satisfactory.
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Masanori Hidaka
1975 年 39 巻 1 号 p.
103-108
発行日: 1975/07/15
公開日: 2007/05/29
ジャーナル
認証あり
The magnetic structure of KMnF
3 has been deduced from group-theoretical consideration based on the new space group
P4⁄
mbm. In the uniaxial antiferromagnetic region, the structure is of the G-type with the sublattice magnetization parallel to the
z axis, while in the weak-ferromagnetic region the structure is of the pseudo-G-type with the sublattice magnetization nearly parallel to the
x (or
y) axis and slightly canted towards the
y (or
x) axis. These proposed structures are examined by trying an interpretation of the magnetic torsion curves given by Heeger
et al. [Phys. Rev.
123 (1961) 1652]. By taking the crystallographic and magnetic domain structures into account, it is shown that the new magnetic structures are fully consistent with the torsion curves including the magnetic-field dependence.
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Yoshihisa Suido, Yositaka Yosida, Shoichi Mase
1975 年 39 巻 1 号 p.
109-116
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
From the measurements of the giant quantum attenuation of longitudinal sound waves, the anisotropy of the spin splitting factor γ (the ratio of the spin splitting to the Landau splitting) for the holes in principal ellipsoid in antimony has been determined for two cases,
H⁄⁄
a binary-trigonal plane and
H⁄⁄
a bisectrix-trigonal plane. The values of γ obtained for
H along the binary (
x-), bisectrix (
y-) and trigonal (
z-) axes are as follows: γ
xh=0.43, γ
yh=0.80, and γ
zh=0.74. The deformation potential tensor components
Diih for the principal hole-ellipsoid have also been determined from an analysis of line shapes of the attenuation curves. The results obtained are as follows: |
Dxxh|=4.7 eV, |
Dyyh|∼1.6 eV, |
Dzzh|=0.62 eV, and
Dyyh⁄
Dxxh∼−0.34.
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Kunihiko Iwasaki, Masahiro Koiwa, Ryukiti R. Hasiguti
1975 年 39 巻 1 号 p.
117-124
発行日: 1975/07/15
公開日: 2007/05/29
ジャーナル
認証あり
The internal friction of cold worked dilute copper alloys (Cu–Ag and Cu–Au) is studied in the temperature range between −150°C and +140°C with an inverted torsion pendulum. The internal friction peaks which appear in cold worked pure copper are suppressed by the addition of solute atoms. In place of them two new peaks
Pa and
Pb are found at about −125°C and −60°C, respectively, in silver doped specimens, while no new peak is observed in gold doped ones. Detailed investigations are carried out on the behavior of the peak
Pb, which is interpreted to be due to thermal unpinning of dislocations from pinning silver atoms. The behavior of the other peaks is also described.
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Kyôzô Takeyama, Kazuo Kitahara
1975 年 39 巻 1 号 p.
125-131
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Fluctuations of the carrier density causes instabilities of the electrically uniform state in conductors with a negative differential resistance. Transitions to electrically non-uniform states are studied, based on evolution criterions derived after Glansdorff and Prigogine. The method enables us to analyze the phenomena in an analogous way as we discuss the thermodynamics of the usual two-phase separations.
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Tadashi Itoh, Shin-ichiro Narita
1975 年 39 巻 1 号 p.
132-139
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
The wavelength derivative absorption spectra of Cu
2O have been measured in the energy regions of the yellow and green exciton series over a wide temperature range. Three phonon assisted indirect transition edges are newly found at 4.2 K, and the structures associated with direct transitions to the 1s state and the higher exciton states are observable up to room temperature. By analysing the impurity associated transition and using the Rydberg constants for both the yellow and the green exciton series, we determine the effective mass of the electron in the conduction band and those of the holes in the valence bands to be
me*\simeq0.99
m0,
mlh*\simeq0.64
m0 (light hole) and
mhh*\simeq1.40
m0 (heavy hole).
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Tadashi Itoh, Shin-ichiro Narita
1975 年 39 巻 1 号 p.
140-147
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
The line shapes of the exciton absorption spectra of Cu
2O at various temperatures obtained by the wavelength modulation technique have been analysed on the basis of Toyozawa’s theory. The n-th exciton lines for the yellow (
n≥2) and the green exciton series have asymmetric Lorentzian line shape and their half value widths are proportional to
T (the absolute temperature) in a high temperature region. While the yellow 1s line has a characteristic line shape with the half value width proportional to
T2. The temperature change of the spectrum indicates that the
Γ12− optical phonon in Cu
2O plays a predominant role in the exciton-phonon interaction.
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Katumi Suzuki, Noboru Miura
1975 年 39 巻 1 号 p.
148-154
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Quantum effects have been observed in the cyclotron resonance of holes in GaSb and Ge by using a far-infrared H
2O laser (λ=119 μm) in pulsed high magnetic fields up to 330kG. An analysis of the experimental results in GaSb was made on the basis of the method of Pidgeon and Brown, and on referring to the assignment of the peaks in Ge made by Hensel and Suzuki. The experimentally determined Luttinger parameters of GaSb are: γ
1=12.4, γ
2=3.9, γ
3=5.4, κ=3.2. In Ge, the magnetic field dependent mass shift was observed at 119 μm.
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Masahiro Saidoh, Jun-ichi Hoshi, Noriaki Itoh
1975 年 39 巻 1 号 p.
155-161
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Formation of the
H,
HA,
HZ and
V4 centers in pure, Na
+-doped or Ca
++-doped KBr has been measured within the time constant of the thermal annihilation of the
H center between 80 K and 200 K using the flush radiolysis technique. It has been found that the interaction volumes of the radiation-induced dynamic motion of the interstitial halogen with a Na
+ impurity, a Ca
++ impurity of an
H center increase with an activation energy, 0.03 eV between 80 K and 200 K. It is pointed out that the increase in the interaction volume with temperature is due to the increases in the average range of the replacement sequence and that the increase in the average range explains the increase in the
F center production efficiency between 80 K and 200 K.
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Bin Okai, Jiichiro Yoshimoto
1975 年 39 巻 1 号 p.
162-165
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
The pressure dependence of the structural phase transition temperature,
Ta, in SrTiO
3 has been measured up to 30 kbar. The initial slope of 1.8 deg/kbar by Sorge
et al. (1970) has been reaffirmed contrary to the prediction by Fossheim and Berre (1972): d
Ta⁄d
p=0.5 deg/kbar. Above 8.5 kbar the transition temperature shifts nonlinearly with increasing pressure. As for the cubic-tetragonal transition temperature of KMnF
3 the measurements to 10 kbar show a linear shift: d
Ta⁄d
p=3.9 deg/kbar. Above 10 kbar a deviation from linearity seems to set in.
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S. S. Bawa, L. K. Khanna
1975 年 39 巻 1 号 p.
166-169
発行日: 1975/07/15
公開日: 2007/05/29
ジャーナル
認証あり
Dielectric constant of compressed AgNa (NO
2)
2 powders of various particle size has been measured at 1 kHz over a wide range of temperature. The dielectric constant decrease with the decrease in particle size. Dielectric anomaly at the ferroelectric transition has completely disappeared for powders of less than 100 μm particle size. The measured values of the dielectric constant even for the biggest particle size are lower than the theoretically expected value for a polycrystalline sample. A reasonably good explanation of such a behaviour has been given by postulating the formation of defective surface layer of low dielectric constant.
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Naoaki Yoshida, Michio Kiritani, F. Eiichi Fujita
1975 年 39 巻 1 号 p.
170-179
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Aggregation process of irradiation-induced point defects in iron is examined between room temperature and 400°C with a high voltage electron microscope. In the whole temperature range examined interstitial type dislocation loops are formed. The loops formed between slightly above room temperature and 350°C have flower-like shape. Especially the petalous loops formed around 300°C are divided into many small loops at the latter stage of irradiation by absorving mobile vacancies. The formation of the loops in the pre-irradiated specimen also tells that the vacancies become mobile at about 300°C. Analyzing the nucleation of the loops by using the chemical rate theory considering the effects of impurity atoms one obtains the activation energy for interstitial migration as about 0.26 eV.
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Masanori Hidaka
1975 年 39 巻 1 号 p.
180-186
発行日: 1975/07/15
公開日: 2007/05/29
ジャーナル
認証あり
The crystal structure of KMnF
3 at 50 K has been determined and refined by least squares method. The crystals are tetragonal with space group
P4⁄
mbm and cell dimensions:
at=5.894 and
ct=8.348Å (
Z=4). Intensity data were collected from Weissenberg photographs by using a microphotometer. Refinement on 122 superlattice reflections reached
R=0.17. The structure is a slight distortion of the perovskite structure in which the tilting of MnF
6 octahedra, around the [001]
t axis, is observed only on the alternate (001)
t planes. The structure is described in terms of successive condensation of the
R25 and
M3 soft phonon modes.
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Takeshi Kambara
1975 年 39 巻 1 号 p.
187-194
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Properties of distorted localized orbitals obtained from the Adams-Gilbert equation are studied. An account is given of a relationship between distorted localized orbitals \varphi in the real manifold and orbitals φ
0 of a chosen “model subsystem”. Each \varphi can be written as a sum of a “localized orbital” φ and the remaining part δφ in the virtual manifold. The orbital φ is defined through an equation with optimized pseudopotential which makes deviation of φ from the corresponding model orbital φ
0 least. It is shown that φ is equal to φ
0 up to the first order in δφ. Appropriateness of the choice of model subsystems or model orbitals in a particular polyatomic system can be judged by the relative magnitude of δφ to φ
0. That is, the smaller |δφ⁄φ
0| is, the better the choice of model orbitals. An expression of δφ convenient for a calculation is given.
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Tadasu Suzuki, Hiroshi Tanaka, Makoto Saito, Hayao Igawa
1975 年 39 巻 1 号 p.
195-199
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
The differential cross section for resonance scattering of electrons by neon near 16 eV was evaluated numerically on the basis of the partial wave method using the phase shift parameter analysis of Fano. The calculation of the differential cross section for various scattering angles was carried out under the assumption of a natural line width
Γ=10 meV and the total energy resolution
ΔE=40 meV, and then compared with the experimental results of Andrick, Ehrhardt and Eyb. The good agreement between them indicates the validity of the assumed conditions for the computation.
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Tadasu Suzuki, Hiroshi Tanaka, Makoto Saito, Hayao Igawa
1975 年 39 巻 1 号 p.
200-204
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
The effect of the spin-polarization of the incident electrons on the differential cross section of elastic resonance scattering by neon is evaluated numerically. The differential cross section of the resonance scattering is found to be strongly dependent on the degree of spin-polarization of the incident electrons. This result indicates that resonance scattering by neon can be used as a spin-polarization analyzer for incident electrons as well as a spin polarizer.
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Iwao Yamashita
1975 年 39 巻 1 号 p.
205-212
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
The initial rotational population distribution of OH (
A2Σ+) produced by Lyman Alpha photon impact on H
2O has been measured by the crossed-beam technique. The light source employed is of the plasma jet type, and it is highly monochromatic. The result obtained tells that the population is negligibly small in the lower rotational levels, and the overall distribution curve looks like an asymmetric peak with a narrow half-width situated at
K′=17 to 22.
Measurements have also been made in the target-gas method. However, these results are sensitive to the pressure of the target gas in the fluorescence cell, and they are all different more of less from the result obtained by the crossed-beam technique. Discussions about the discrepancy have led to secondary production of OH(
A2Σ+) due to long lived species such as OH(
X2Π), O(
1D) and H(
2S) because of their random motions in the target gas.
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Toshitaka Idehara, Mitsuyoshi Takeda, Nobuto Miyama, Yoshio Ishida
1975 年 39 巻 1 号 p.
213-220
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
The backward wave along the magnetic field is observed in a Maxwellian plasma. The propagation characteristics of the wave is explained in terms of the dispersion relation of the Bernstein wave. When an electron beam with an intensity above a certain critical value is injected into the plasma, a strongly excited wave is observed, whose frequency spectrum is very sharp. It can be shown from the measurement of the amplification that the waves excited are not explained in terms of a growth rate of thermal noise amplified by the convective instability but in terms of a self-oscillation due to the absolute instability. Dependence of the spontaneously excited wave on the plasma electron temperature and the electron beam parameters is investigated in detail.
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Masatomo Sato
1975 年 39 巻 1 号 p.
221-228
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
In spite of their small relative number, the high energy charged fusion products in a thermonuclear plasma,
e.g., the α-particles form D-T reactions, can have certain influences on the dispersion characteristics of the plasma. In this paper, low-frequency gradient modes (drift waves) in a uniform magnetic field is considered in the electrostatic approximation taking the relative number
Δ=
nα⁄
ne(<<1) and the relative gradient ρ=∇ln
nα⁄∇ln
ne (|ρ|∼1) as parameters, where
nα and
ne are the density of α-particles and electrons, respectively. It is found that in the normal case with ρ>0, the α-particles act to enhance/reduce the stability in the kinetic/hydrodynamic regime of density-gradient modes at small values of the perpendicular wavenumber; the contrary holds for the rather peculiar case of ρ<0. The α-particles have no significant direct effects on the temperature-gradient modes.
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Katuhiko Goda
1975 年 39 巻 1 号 p.
229-236
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Numerical stability in regard to some difference schemes for the Korteweg-de Vries (K-dV) equation is discussed. A stability criterion for the leap-frog explicit scheme which has been used by Zabusky and Kruskal for solving the initial value problem is proposed. It is shown by the energy method that this criterion implies the stability of a linearized difference equation closely related to the scheme concerned. Further, an unconditionally stable implicit scheme is proposed. Some numerical comparisons between the two schemes are given. At the same time, a numerical comparison with analytical solutions of the K-dV equation is also given. These results agree well with each other.
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Tsunehiko Kakutani, Kazuo Matsuuchi
1975 年 39 巻 1 号 p.
237-246
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
The effect of viscosity is examined on long gravity waves of small but finite amplitude. The reductive perturbation method combined with the usual boundary layer theory reveals that the inviscid Korteweg-de Vries equation is not affected by the viscosity if O(α
−5)<
R, where
R is the Reynolds number and α(<<1) the wavenumber. For O(α
−1)<
R≤O(α
−5), the effect of viscosity modifies the Korteweg-de Vries equation and yields new types of equation. On the other hand, for
R<O(α
−1), the complex phase velocity becomes purely imaginary and the free surface is found to be governed by a nonlinear diffusion equation which was first obtained by Nakaya.
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Haruhiko Takada
1975 年 39 巻 1 号 p.
247-252
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Separated flow past a two-dimensional smooth curved bluff body can be solved by the use of a free-streamline theory so long as the base pressure and the separation position are prescribed as empirical parameters. The purpose of the present paper is to eliminate one of these parameters by determining the separation position as a function of the base pressure with the help of the boundary layer theory. Calculations were performed for cases of a subcritical and a transcritical flow past a circular cylinder. Although some discrepancy is seen to exist between the theory and the experimental data, it is shown that solutions of Kawaguti, and of Bluston and Paulson can be included in the present theory as special examples. Furthermore, a conclusion of the latter paper is criticised from the viewpoint of the present theory.
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Hiroo Totsuji
1975 年 39 巻 1 号 p.
253-254
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Thermodynamic properties of a two-dimensional system of classical electrons on the surface of a dielectric substance are investigated on the basis of an expansion with respect to the plasma parameter ε=2π
ne4⁄
T2, where
n denotes the surface number density. The correlation energy density
Ec and the pressure
P are calculated exactly to the order of ε:
Ec⁄
nT=2[
P⁄
nT−1]=(1⁄2)ε[ln(2ε)−1+2γ], γ=0.5772···.
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Ken Ichi Arai, Noboru Tsuya, Kiyoo Sato, Kengo Adachi
1975 年 39 巻 1 号 p.
255-256
発行日: 1975/07/15
公開日: 2007/05/29
ジャーナル
認証あり
The magnetostriction constants of CoS
2 single crystal were measured by a capacitance method in a temperature range from liquid N
2 to the Curie temperatures.
The constants λ
100 and λ
111 are −1.9×10
−6 and 5.7×10
−6 at liquid
N2 temperature respectively, and the absolute values of the constants decrease monotonically with the increase of the temperature.
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Muneyuki Date, Mitsuhiro Motokawa, Hidenobu Hori, Shin-ichi Kuroda, Ke ...
1975 年 39 巻 1 号 p.
257-258
発行日: 1975/07/15
公開日: 2007/05/29
ジャーナル
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The exchange interaction in a famous antiferromagnetic linear chain system of CTS (copper tetra-amine sulfate, Cu(NH
3)
4SO
4H
2O) was investigated using millimeter and newly developed submillimeter spin resonance techniques. The “intrachain” exchange interaction
J was determined to
J⁄
k=0.24±0.08 K which is less than one tenth of the exchange interaction to be expected from the linear chain model. The result shows that CTS can not be considered as a typical example of a linear chain antiferromagnet.
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Yoshitami Ajiro, Shun-ichi Matsukawa, Tetsuo Yamada, Taiichiro Haseda
1975 年 39 巻 1 号 p.
259-260
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
The ESR line width of a typical 1d
H S=1/2 AF CuCl
2·2NC
5H
5 has been measured between 1.3 and 300 K. As temperature is lowered the width anomalously decreases down to 5 K with an approximated relation
ΔH∝χ
T and it turns to increase with a relation
ΔH∝
T−1.2. It is suggested that the unusual behaviors can be understood by considering the dominant role of the
q=0 fluctuations at higher temperatures and also of the
q=
K0 fluctuations at lower temperatures in the spin dynamics for S=1/2 AF chains. The critical broadening for 3d ordering will appear at temperatures much nearer
TN.
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Setsuo Ichimaru
1975 年 39 巻 1 号 p.
261-262
発行日: 1975/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Based on the microscopic theory of transport processes, the Buneman resistivity is calculated to be (4πα⁄\sqrt3ω
p)(
me⁄2
mi)
1⁄3, where ω
p2=4π
ne2⁄
me and α=〈δ
n2〉⁄
n2. The saturation level of turbulence in the Hamberger-Jancarik experiment is inferred to be α\simeq0.35; a number of possible mechanisms for the saturation are discussed.
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Hiroshi Oshiyama
1975 年 39 巻 1 号 p.
263-264
発行日: 1975/07/15
公開日: 2007/05/29
ジャーナル
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A new magnetic system of Tokamak for a divertor and for operating Tokamak stationarily by using the modified quadrupole magnetic field is proposed. Numerical calculations of the system using Biot-Savart’s low show that the suitable magnetic surfaces and the scrape-off flux exist by chosing the field parameters.
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