Magnetic resonance transition

From Figure 1.2 we can see that nuclear magnetic resonance transitions... 

The first level to be studied in detail by Tichten [35] was the N = 2 level of both para-Hi and ortho-H2. He measured a series of fixed-frequency magnetic resonance transitions, determining effective g- values and proving the identification of the c3nu state in the process. An effective Zeeman Hamiltonian may be written, in the space-fixed axis system,... 

The authors do not mention the values of the nuclear g-factors, but we may take them to be gF = +2.628 87 and gN = +0.403 76 nuclear Bohr magnetons. Consequently it is now a simple matter to calculate the energies of the 30 levels for a range of magnetic fields between 9400 and 10 600 G the magnetic resonance transitions are those which obey the selection rules AM/ = 1, AMn = AMp = 0 and their frequencies may also be calculated. 

Figure 9.26. Left lower rotational levels of SO 3 in zero magnetic field, and the transitions observed (see chapter 10). Right microwave magnetic resonance transitions observed in SO at 8762 MHz [56].

Figure 9.28. Zeeman levels for N = 0 and 1 of NH 3E (v = 0) and the observed far-infrared laser magnetic resonance transitions [58]. These were recorded using four different FIR lines at 31.7615, 32.1466, 33.0822 and 33.1922 cm-1.

Figure 9.29. The laser magnetic resonance transition N=l,J=l, M = 0—> N = 2, J = l, M = 1 for ND 5 X. showing fully resolved hyperfine splitting from both nuclei, each with spin 1 [58]. The laser frequency was 991.7778 GHz.

Figure 11.9. Radiofrequency magnetic resonance transitions observed by double resonance at two different frequencies for OH in the A 2 + state [10].

Figure 11.13. Energy levels of II2 in the N = 1 level of the G E+ state in an applied magnetic field, and the observed magnetic resonance transitions [21],...

Historically this field is an extension of the optical detection of magnetic resonance transitions of... 

The ZFS of the Trp triplet state are shown in Fig. 1, along with the location of the principal axes. Magnetic resonance transitions occur at the three frequencies, v, of ( D E )lh and 2 E /h. Assignment of any two of the transitions allows determination of the absolute values of the zero-field parameters, D and JE]. Because the ZFS is produced by the... 

The following is the personal view of the author, based on his experience with the discussed techniques. The advantage of frequency-domain techniques, described in Sects. 2.1-2.3 is that no external field is required and ZESs are obtained directly. The ability to apply a small field is useful, especially at frequencies above ca. 20 cm in order to distinguish magnetic resonance transitions from molecular vibrations and other phonon-type excitations. The advantage of field-swept techniques is that field-swept spectra tend to have flatter baselines, which increases sensitivity. Cavity and other resonator methods, which are only easily implemented in field-swept experiments, are much more sensitive. Therefore, single-crystal... 

Fig. 10. Transient response of the phosphorescence intensity of bovine scrum albumin monitored at 414 nm to a microwave fast-passage magnetic resonance transition which occurs at / = 0. The magnetic resonance, which is centered at 1.657 GHz is due to the tryptophan Tz Tx transition (see Fig. 8). The temperature is 1.3 K, no external magnetic field is present, the solvent is 50% ethylene glycol-water, and the sample is continuously optically pumped. The transient decays os a single exponential since only Tj, is radiative. If both and T had been radiative, a response such as shown in Fig. 1 of Winscom and Maki 8) would have been observed. (From Zuclich et al. lOOh)...

Fig. 14. Zero-zero phosphorescence emission band of tryptophan in ethylene glycol-water at 1.25 K (top). Below this, in order, are shown the half-width of the zero-field 2 magnetic resonance transition, the zero-field parameter E, the zero-field parameter >, and the half-width of the zero-field f) —1 transition, each as a function of the monitored optical wavelength with narrow monochromator slits. (From von Schutz et al.

Fig. 1. Schematic diagram of a triple resonance atomic beam apparatus. Between source S (a hot oven) and detector D, magnets A and B produce inhomogeneous deflecting fields, and act as polarizer and analyzer magnet C produces a homogeneous field in which magnetic resonance transitions occur at loops A, B and C. Resonance is detected by the deflection of atoms away from the detector D, if the gradients in magnets A and B are in opposite directions.

To keep Eqs. 15 17 more ludd, only one out of the three triplet sublevels was considered. Actually, in purely optical experiments with pentacene in p-terphenyl [36], the correlation decay seems to be dominated by a single level. A more detailed analysis of correlation experiments in connection with microwave induced magnetic resonance transitions between the triplet sublevels (see Section 1.6) allowed to determine the kinetics of all three triplet sublevels of a single pentacene molecule [69]. 

Figure 6. Comparison of the lineshapes of the Y -]Zy magnetic resonance transition for a single molecule (top) and for an ensemble of about 10 molecules (bottom). In contrast to the previous figure the vertical scale corresponds to a decrease of fluorescence. The ensemble spectrum was recorded with the laser tuned to the top of the inhomo-geneously broadened 0 absorption line whereas the single molecule was selected in the red wing of this line.

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