qspec.alpha_atom  (  alpha ,  v  )[source]

The angle in the rest frame of the atom $\alpha^\prime = \arccos\left[\frac{(v/c) + \cos(\alpha)}{1 + (v/c)\cos(\alpha)}\right]$.

Parameters:

alphaarray_like

The angle $\alpha$ between a velocity- and a wave-vector in the laboratory frame (rad).

varray_like

The velocity $v$ of a body (m/s).

Returns:

outarray_like

The angle $\alpha^\prime$ between the velocity- and the wave-vector in the atom's rest frame (rad).