The suggestion is also made that Co& may be strongly dissociated by the metastable Xe atoms (and H~O somewhat less strongly), thus producing oxygen atoms which combine to form the O~molecules; (D(CO~) =5.5 v, D{HgO) =5.0 v). If so, the fact that CO did not yield the bands would indicate that the dissociation energy of CO is greater than the energy of the upper metastable state of Xe, namely 9.4 volts. (Energy of lower metastable state equals 8.3 v.

The exchange of energy between a system of nuclear spins immersed in a strong magnetic field, and the heat reservoir consisting of the other degrees of freedom (the "lattice") of the substance containing the magnetic nuclei, serves to bring the spin system into equilibrium at a finite temperature. In this condition the system can absorb energy from an applied radiofrequency field. With the absorption of energy, however, the spin temperature tends to rise and the rate of absorption to decrease. Through this "saturation" effect, and in some cases by a more direct method, the spin-lattice relaxation time T 1 can be measured. The interaction among the magnetic nuclei, with which a characteristic time T 2 ' is associated, contributes to the width of the absorption line. Both interactions have been studied in a variety of substances, but with the emphasis on liquids containing hydrogen.Magnetic resonance absorption is observed by means of a radiofrequency bridge; the magnetic field at the sample is modulated at a low frequency. A detailed analysis of the method by which T 1 is derived from saturation experiments is given. Relaxation times observed range from 10-4 to 10 2 seconds. In liquids T 1 ordinarily decreases with increasing viscosity, in some cases reaching a minimum value after which it increases with further increase in viscosity. The line width meanwhile increases monotonically from an extremely small value toward a value determined by the spin-spin interaction in the rigid lattice.

The exchange of energy between a system of nuclear spins immersed in a strong magnetic field, and the heat reservoir consisting of the other degrees of freedom (the "lattice") of the substance containing the magnetic nuclei, serves to bring the spin system into equilibrium at a finite temperature. In this condition the system can absorb energy from an applied radiofrequency field. With the absorption of energy, however, the spin temperature tends to rise and the rate of absorption to decrease. Through this "saturation" effect, and in some cases by a more direct method, the spin-lattice relaxation time T 1 can be measured. The interaction among the magnetic nuclei, with which a characteristic time T 2 ' is associated, contributes to the width of the absorption line. Both interactions have been studied in a variety of substances, but with the emphasis on liquids containing hydrogen.Magnetic resonance absorption is observed by means of a radiofrequency bridge; the magnetic field at the sample is modulated at a low frequency. A detailed analysis of the method by which T 1 is derived from saturation experiments is given. Relaxation times observed range from 10-4 to 10 2 seconds. In liquids T 1 ordinarily decreases with increasing viscosity, in some cases reaching a minimum value after which it increases with further increase in viscosity. The line width meanwhile increases monotonically from an extremely small value toward a value determined by the spin-spin interaction in the rigid lattice.

No abstract

No abstract