Hi Federico,
indeed I believe there is a way to isolate a single isotope using the usrmed.f
routine. It seems that the variable IAZTRK
kindly provides the origin of the particle and could be used to filter.
INCLUDE 'trackr.inc'
IF (IAZTRK .NE. 90232) THEN
WEE = ZERZER
END IF
Cheers,
Markus