NUCLEAR SPIN RELAXATION IN GASES AND LIQUIDS: II. MOLECULAR HYDROGEN

1963 ◽  
Vol 41 (10) ◽  
pp. 1580-1590 ◽  
Author(s):  
Myer Bloom ◽  
Irwin Oppenheim
Keyword(s):  
Intermolecular Interactions ◽  
Spin Relaxation ◽  
Nuclear Spin ◽  
Correlation Functions ◽  
Molecular Hydrogen ◽  
Nuclear Spin Relaxation ◽  
Approximate Theory ◽  
Rotational States ◽  
Schwinger Model

T1 and T2 in H2 are expressed in terms of correlation functions of the intamolecular interactions in the Schwinger model. A relationship between these correlation functions and correlation functions of the intermolecular interactions is derived. An approximate theory of the influence of higher rotational states is given.

scholarly journals Nuclear spin relaxation by intramolecular interactions in gases of homonuclear diatomic molecules

1976 ◽  
Vol 54 (22) ◽  
pp. 2209-2212 ◽  
Author(s):  
Myer Bloom ◽  
Peter Beckmann ◽  
B. C. Sanctuary
Keyword(s):  
High Temperatures ◽  
Spin Relaxation ◽  
Nuclear Spin ◽  
Diatomic Molecules ◽  
Intramolecular Interactions ◽  
Spin Density Matrix ◽  
Nuclear Spin Relaxation ◽  
Nuclear Spins ◽  
Rotational States ◽  
Homonuclear Diatomic Molecules

The differential equations which describe the relaxation of macroscopic observables associated with nuclear spins in homonuclear diatomic molecules are derived using an expansion of the nuclear spin density matrix in terms of irreducible tensors. It is shown, using an intramolecular quadrupole mechanism, that the only difference between nuclear spin relaxation of the ortho- and para-species arises from the rotational states being restricted to odd and even values. This difference is vanishingly small at high temperatures so that the relaxation equations for nuclear magnetization become identical for both species. A previous paper predicting a difference even at high temperatures is shown to be in error and is corrected.

ON THE NUCLEAR SPIN RELAXATION IN HYDROGEN GAS

1961 ◽  
Vol 39 (6) ◽  
pp. 870-880 ◽  
Author(s):  
G. T. Needler ◽  
W. Opechowski
Keyword(s):  
Relaxation Time ◽  
Explicit Expression ◽  
Spin Relaxation ◽  
Nuclear Spin ◽  
Low Temperatures ◽  
Room Temperature ◽  
Hydrogen Gas ◽  
Nuclear Spin Relaxation ◽  
Approximate Theory ◽  
Nuclear Spins

The Schwinger formula for the relaxation time T1 of nuclear spins in hydrogen gas is valid only for sufficiently low temperatures. In this paper an approximate theory of T1 is developed valid for any temperature. An explicit expression is given for T1 valid for temperatures up to room temperature; this expression reduces to the Schwinger formula for sufficiently low temperatures.

scholarly journals Nuclear-Spin Relaxation in Low-Density Molecular Hydrogen at Room Temperature

1972 ◽  
Vol 6 (4) ◽  
pp. 1684-1686 ◽  
Author(s):  
Peter A. Beckmann ◽  
E. Elliott Burnell ◽  
Krovvidi Lalita ◽  
Robin L. Armstrong ◽  
Kenneth E. Kisman ◽  
...  
Keyword(s):  
Spin Relaxation ◽  
Nuclear Spin ◽  
Molecular Hydrogen ◽  
Room Temperature ◽  
Nuclear Spin Relaxation ◽  
Low Density

Nuclear Spin Relaxation by Defect Mechanisms of Self-Diffusion in Crystals

1971 ◽  
Vol 26 (11) ◽  
pp. 1816-1824 ◽  
Author(s):  
D. Wolf
Keyword(s):  
Temperature Dependence ◽  
Spin Relaxation ◽  
Nuclear Spin ◽  
Correlation Functions ◽  
Nuclear Spin Relaxation ◽  
Cubic Crystal ◽  
Self Diffusion

The present paper shows how to incorporate the correlation between successive nuclear jumps, which are well known to play a role in defect mechanisms of self-diffusion in crystals, into the calculation of the correlation functions describing the temperature dependence of the nuclear spin relaxation in solids. The treatment is based on an extension of Torrey’s theory of nuclear spin relaxation by randomly migrating nuclei. Explicit and detailed results are given for the monovacancy mechanisms of self-diffusion in an isotopically pure face-centred cubic crystal.

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