Static Longitudinal Field Relaxation
Relaxonomy --> here
When the muon spin polarization <math>\vec{P}</math> is initially in the same direction as the applied magnetic field <math>\vec{B}</math>, we call that the <math>z</math> direction. This is called the longitudinal field (LF) geometry. The relaxation of <math>\vec{P}</math> is then usually described by
where the lower case <math>g</math> is used (instead of the more general <math>G</math>) to designate a static relaxation function, just like in ZF. (Dynamic cases will be treated later.)
In the limit where <math>B \gg </math> any random local magnetic fields (RLMF), this formulation is valid. (At last, a "low-bogosity" case!) However, in modest applied fields (B <math> \sim </math> RLMF) it is subject to the same caveats as the ZF case, which see.