ZMT zurich med tech

In Sim4Life, the complex field S(x,y,z,f0) is (one half of) the cross product of the complex fields E(x,y,z,f0) and H(x,y,z,f0), both of which are the complex representation of harmonic fields (actually S = 0.5 E cross H*, where H* is the complex conjugate of H)
The time-averaged Poynting vector (if you want the power flow) is given by Re(S)

See the Wikipedia article (https://en.wikipedia.org/wiki/Poynting_vector) for more detail.

EDIT: this post was corrected to reflect the notations used in Sim4Life, namley that S(x,y,z,f0) is already the time-averaged quantity and includes the factor 1/2.

@LJ thanks

One needs to be careful with the naming of the quantities. Notice that B1(x,y,z,f0) refers to a field with two components, namely (B1+, B1-) !!!! I personally find the name a bit unfortunate but it was directly taken from MRI jargon where they denote B1 to the RF B-field to distinguish it from the static magnetic field, denoted as B0.

Do NOT confuse with B(x,y,z,f0) that is a C^3 quantity with (Bx, By, Bz) components!!

Check in the manual B1(x,y,z,f0) for more details.