GCR-ALLF source definition issues

Versions

Please provide the used software versions.

FLUKA:4.5.1
Flair:

Description

While using the GCR-ALLF card, the manual explained that WHAT(2) means height of the (infinitely large surface) source when set to negative values, and means radius when set to positive. The explanation is not so clear and raises a few concerns.

1.Is the height WHAT(2) or the absolute value of WHAT(2)? (for example if WHAT(2) is -50.0, is the height -50cm or 50cm)

2.By default, does the source generate particles in one direction or both directions? If in one, is it up or down? Does it shoot all particles in the same direction or evenly spread over solid angle?

3.Is it possible to set the source in the other half of the world (cuz if surface source is only when WHAT(2) <0 it naturally could only be in one half of the geometry)? And is it possible to set the source surface in a direction other than the default xy-plane?

Idk but my estimators are giving out zero outputs so there’s gotta be something wrong with my comprehension of the manual. Thx.

Input files

Please upload all relevant files. (FLUKA input file, Flair project file, user routines, and data files)