Spin relaxation of polarized helium-3 in the magnetic field of a Helmholtz pair

The fact that the motion of the atoms of helium-3 gas is so quick that the spins cannot follow the change of direction of an inhomogeneous magnetic field adiabatically is an important spin relaxation mechanism. The spin relaxation rates are calculated for a spherical sample situated at the centre of a Helmholtz pair. The calculation is made for the first two nonvanishing terms in the inhomogeneity, the fourth and sixth degree terms.