power outflow, time average mwp.nPoav

Hello,
using a 2D-axial symetric model in rf-module (plasma),

on my coaxial power input port I put 50 W..
inner diameter 8mm, outside 50mm (21 mm radial distance).

how does mwp.nPoav come on -800 W/m ?

50W distributed on 2pi angle.. gives me the power per angle (the linear value?) on my 21 mm distance.
so 50/(2.pi.21) would give me the maximum W/m value on mwp.nPoav ?
I get 380 W/m and not some 800 calculated..

where is my mistake?

how can I verify these 50W, on 3.5 there used to be boundary integration.. how to use that on 4.3 ?
in derived values? or data sets?

thanks,

lukas