B1 rms field

If you want to visualize the RMS value for a field, you will need to perform scaling manually.
Select the desired field in the sensor outputs, then go to Field Data Tools > Field Scaling.
Scale the field by 1/sqrt(2) by entering 0.7071 as the Scale Factor.
Then you can visualize the slice as you normally would.

Note that the above is only true in the case of a harmonic signal, which is why Sim4Life does not provide the RMS by default. It is up to the user to calculate the RMS based on their knowledge of the signal.
If you are interested in B1+/B1, the rotational components of B1 are by definition constant in time and so their RMS magnitudes are equal to their absolute magnitudes.