A Study of Multiple Quantum Transitions by Rotary Saturation of Nuclear Magnetic Resonance

Multiple quantum transitions between the spin Zeeman levels of proton in water has been investigated by the rotary-saturation method in nuclear magnetic resonance. Experiments were carried out up to 3rd-order multiple quantum transitions. A quantitative analysis of the rotary-saturation data were accomplished by the use of the calculation of high-order quantum mechanical perturbation. The experimental results are in good agreement with the perturbation theory

Frequency Modulation Method for Performing Adiabatic Demagnetization in the Pulsed Nuclear Magnetic Resonance

Frequency modulation method for performing adiabatic demagnetization in the rotating reference frame in the pulsed NMR has improved. Using simple circuits which are described in this paper, we have been able to change the frequency by 146 KHz. This large deviation of frequency corresponds to a change in h_0 field for Li^7 of 88 G and sufficiently satisfies the condition h_0≫H_1. With the improved method, spin locked state of the most nucleus is perfectly performed and then this method may be useful for many pulsed NMR experiments

Calculation of the Distributions of Magnetic Fields used in Rotary-saturation Experiments

In order to interpret the disagreement between the experimental results and the theory in the rotary-saturation study, the distributions of the magnetic-field intensities are calculated. It is found that this discrepancy is considerably reduced by using these distributions, but it is not sufficient to consider only these distributions. It is necessary to consider another physical factors for the correction of this discrepancy. The actual calculation is made over 435600 sites in the sample by using numerical integrals by computor

The Measurement of a Magnetic Field Strength in the Second Rotating Reference Frame

To perform a rotary-saturation experiment, it is necessary to add an audio channel to a standard nuclear-magnetic resonance apparatus. In this paper, the method for measuring of the strength of the magnetic field produced by the audio coils is represented. Measurement is performed by treating with the behaviour of the magnetization in the second rotating reference frame. The error of the results by this method is at most a few percents

ヒカリ ポンプ サレタ F チュウシン ノ ジキ エン ヘンコウ ブンキョクド ト スピン コンゴウ カテイ

The pumping photon energy E_ dependence of the net spin-mixing parameter ε_t and δ(1-2ε_) for KI, where ε_ is the spin-mixing parameter in the nonradiative relaxation process of pumping F center, are determined from the analysis of the magnetic circular polarization of F center emission observed. These experimental dependences are explained using the theoretical plots of ε_0 and δ as well as assuming the empirical E_ dependence of ε_. The ω dependence of the spin polarization is estimated using these spin mixing parameter

コウオン チョウデンドウタイ YBA2 CU3 O7-δ ニオケル カク シジュウキョク キョウメイ ノ ヨコ カンワ

The anomaly of transverse relaxation rate of YBa_2Cu_3O_ is mainly observed at 35K and near superconducting transition. The anomaly at 35K can not be explained by dynamical factor. It is considered that the static factor causes the anomaly and it is the change of anisotropy of indirect interaction between nuclear spins because the change of shape of decay curve accompanies with the anomaly. If the interaction between electron spin and nuclear spin obeys Mila-Rice theory even in superconducting state, it is considered that the change of the anisotropy is owing to change of electron spin correlation. As for the anomaly near superconducting transition it seems to be owing to an extraordinarily slow motion such as softening

NMR ニヨル コタイチュウ ノ タコウシ キュウシュウ カテイ 2 ジッケン

The theory of multiphoton processes in solids by a rotary-saturation method in NMR have been proposed by us. In this paper, we apply the theoretical ideas to fluorine nuclei in a CaF_2 single crystal and analyse the experimental results by the theory. We found evidence that (1) the experimental results of multiphoton processes can be explained fundamentally by the theory but cannot be fully ; (2) one type of single spin-n photon transitions is taking place, but another type of two spin-n photon transitions is not confirmed yet in this crystal ; (3) the linewidths of the multiphoton absorptions are extremely narrow at the magic angle but do not completely vanish because of the presence of a perturbing field ; (4) the effects of the energy level mixing through the dipole-dipole interactions on the multiphoton transitions are negligible over a wide range around the magic angle ; (5) the inhomogeneity of the rf field used to quantize the spin system in the rotating frame affects considerably the results of the rotary-saturation experiments

NMR ニヨル コタイチュウ ノ タコウシ キュウシュウ カテイ 1 リロン

Theoretical investigation of multiphoton processes in solids by rotary-saturation method in NMR is presented. In order to analize the results obtained by this method, it is necessary to introduce the conception of doubly rotating reference frame. The second quantization of a perturbing field, the calculation of the nth order time-dependent perturbation, dipole-dipole interaction and the motion of magnetization are all treated in this frame. Multiphoton transitions in solids have strong dependences on the time during perturbation, the strength of perturbing field and the angle between the direction of quantization and that of perturbing field. Rotary-saturation method produces easily magic angle at which the width of multiphoton absorption lines extremely narrow, so that even higher-order transitions can be observed separately each other