The witness plate view (left, bottom) has the harder spectrum: these two views in this simulation have nearly identical TRs
(listed next to the
respective figures on the left).The witness plate view sees more hot spots, and also has a completely cold object (LEH) in its field of view. The net effect is to reduce the soft emission (LEH replacing wall) while enhancing the hard emission (more hot spots).
1.You can see the somewhat different laser spot sizes (and peak temperatures) for the beams in the two
2.VisRad does not incorporate detailed
opacities.Each surface element is taken to re-emit as a
blackbody.Of course, the net spectrum incident on any one surface,
being the sum of multiple blackbodies, is itself not a blackbody.