Any comment here or anywhere in lines not containing parameters. Avoid
using two points character (colon) since it is reserved to indicate the
following value must be read as a parameter

number of rings: 1

#intrinsic PSF#

Sigma(cm): 0.0361

Crystal thickness (cm): 0.3

Crystal attenuation coefficient (cm -1): 4.407

\#……repeat for each ring …………\#

Nangles: 91

ang0(deg): 180.

incr(deg): 3.0

z0(cm): 0.

\#…………until here………………\#
