Precise measurement of the magnetic moment of17F(I x =5/2+,T 1/2=64.5 s) and its hyperfine interactions in ionic crystals

Hyperfine interactions of β-emitting¹⁷F implanted in single crystals of NaF and CaF₂ were studied. The nuclear magnetic moment of theT ^π=5/2⁺ state was determined with an improved precision to be |μ(¹⁷F;π=5/2⁺,T _1/2=64.5s|=4.72130±0.00025. nm. Isoscalar magnetic moments of the doubly closed shell ±1 nucleon nuclei around mass number 16 were derived and the effective nucleon mass in the nucleus was discussed.     

Temperature dependence of (μ−O) paramagnetic shift in highT c superconductor La2−x Sr x CuO4

In order to investigate the electronic structure around oxygen in superconducting La_2–x Sr _x CuO₄ (x=0.10 and 0.14), precise measurements were carried out on the paramagnetic Knight shifts in the spin rotation frequency of the negative muon bound to the oxygen with reference to antiferromagnetic La_2–x Sr _x CuO₄ (x=0.05). Remarkable temperature as well as crystalline-axis dependence was observed for the highT _c case with a divergence character towardsT _c. Possible mechanisms to explain the observed results are given.     

Exciton and magneto-absorption in tellurium

Infrared magneto-absorption has been investigated in tellurium crystals in magnetic fields up to 45 koe at liquid helium temperatures. When the magnetic field was applied parallel or perpendicular to the c-axis, oscillatory absorptions with many transmission minima involving the exciton absorption were observed. The results were analysed taking into account the complicated structure of the valence band.     

Microwave preionization of the tokamak discharge at the electron cyclotron resonance

When ohmic heating power is applied during the microwave discharge at the electron cyclotron resonance, the plasma current and density build-up become fast and the loop voltage required to start the tokamak discharge decreases. The micro-wave burst observed in the initial stage is reduced and the burst of hard X-rays, occurring at the quasi-steady stage of discharge in the case of no microwave injection, disappears, suggesting that the production of run-away electrons is suppressed strongly.     

A mechanical view of transformation-induced plasticity

Summary A mechanical framework on the transformation-induced plasticity (TRIP) is presented. Numerical illustration of the theory can well explain such phenomena in TRIP as a remarkable increase in elongation at a certain range of temperature in the uniaxial tensile tests and the effect of the residual austenite.

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Eine mechanische Theorie über die umwandlungsinduzierte Plastizität

Übersicht Eine mechanische Theorie über die umwandlungsinduzierte Plastizität (TRIP) wird präsentiert. Es wird durch numerische Illustration gezeigt, daß die Theorie solche Phänomene in TRIP wie eine bemerkenswerte Zunahme der Umformung beim Zugversuch in einem gewissen Temperaturbereich und den Einfluß des residualen Austenit gut beschreiben kann.

     

Azimuthal anisotropy in low-energy ion scattering from SmB6 (001)

A remarkable azimuthal anisotropy has been observed in the scattering of He⁺ ions of an incident energy of 1 KeV from the SmB₆(001) surface. The anisotropy can be interpreted on the basis of “shadowing” effects and clearly reflects the structure of the surface.