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.

Nuclear-spin relaxation in the presence of Mansfield–Ware-4 multipulse sequence

1986 ◽  
Vol 64 (6) ◽  
pp. 733-735 ◽  
Author(s):  
J. S. Blicharski
Keyword(s):  
Relaxation Time ◽  
Spin Relaxation ◽  
Nuclear Spin ◽  
Nuclear Spin Relaxation ◽  
Nuclear Spins

The effective relaxation time T2e is calculated in the weak-collision case, for identical nuclear spins in the presence of a Mansfield–Ware-4 multipulse sequence. The dipole–dipole, quadrupole, and spin-rotational interactions are taken into account.

Longitudinal Relaxation Time Measurements in Hydrogen Gas Mixtures at Low Densities

1975 ◽  
Vol 53 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Robin L. Armstrong ◽  
Kenneth E. Kisman ◽  
Wallace Kalechstein
Keyword(s):  
Relaxation Time ◽  
Spin Relaxation ◽  
Nuclear Spin ◽  
Molecular Nitrogen ◽  
Hydrogen Gas ◽  
Inelastic Collisions ◽  
Nuclear Spin Relaxation ◽  
Longitudinal Relaxation Time ◽  
Preliminary Information

Measurements of the longitudinal nuclear spin relaxation time through the region of the characteristic minimum at 49 MHz in mixtures of molecular hydrogen with the noble gases helium and argon and with molecular nitrogen are reported at 298 K. The data obtained serve as a further test of the basic approximations in the Bloom–Oppenheim theory and provide preliminary information concerning the role of inelastic collisions in the nuclear spin relaxation process.

Nature of uncommon nuclear spin relaxation in NaCl with high concentration of reorienting OH-impurities at low temperatures

1995 ◽  
Vol 134 (1-4) ◽  
pp. 337-339 ◽  
Author(s):  
O. Kanert ◽  
M. Backens ◽  
M. Fricke ◽  
S. Kapphan ◽  
R. Küchler ◽  
...  
Keyword(s):  
Spin Relaxation ◽  
Nuclear Spin ◽  
Low Temperatures ◽  
Nuclear Spin Relaxation ◽  
High Concentration

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.

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.

COPPER SITE NUCLEAR SPIN RELAXATION ANOMALY AND THE KNIGHT SHIFT

2007 ◽  
Vol 21 (18n19) ◽  
pp. 3143-3147
Author(s):  
WEI GUO ◽  
LIKUN WANG ◽  
RUSHAN HAN
Keyword(s):  
Spin Relaxation ◽  
Nuclear Spin ◽  
Knight Shift ◽  
Component Model ◽  
Nuclear Spin Relaxation ◽  
Nuclear Spins ◽  
Local Electron ◽  
Copper Site ◽  
Two Component ◽  
Anomalous Relaxation

In the low doping limit, a high Tc cuprate preserves a two band structure. O2p electrons are itinerant, Cu3d electrons are localized. Therefore the two component model is suitable to describe nuclear spin relaxation at copper sites. In addition to the Korringa process, the hyperfine interaction between nuclear spins and local electron spins is considered, which gives rise to the anomalous relaxation rate 1/T1 = a + bT. The decrease of the susceptibility near Tc, as shown by the Knight shift measurements, can be attributed to the ordering of local spins and the pairing of the uncompensated spins created by holes at the oxygen sites.

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