Assertion: secondary collimator | /r/HasProperty | positioned after either a flattening filter
Facets:
value: for photon therapy
type: PURPOSE
Source sentences:
text: The secondary collimator is positioned after either a flattening filter (for photon therapy) or a scattering foil (for electron therapy).
text: The secondary collimator is positioned after either a flattening filter (for photon therapy) or a scattering foil (for electron therapy).