Function rad_per_ppm 

pub fn rad_per_ppm(te_s: f64, b0_t: f64) -> f64

Phase (rad) per ppm of field at echo time te_s (s) and field strength b0_t (T): 2π·γ·B0·TE with γ/2π = TGV_GAMMA_MHZ_PER_T.