I am using a preprocessor command in my input data to define the particle type.
For instance, I use
#define Particle NEUTRON
and my beam card is
BEAM -99999.0 0 0 0 -1.0$Particle
which corresponds to neutron and works well.
However, if the particle is a PION+
#define Particle PION+
The input data does not work because it seems fluka/flair tries to perform an addition here.
The error is
*** Invalid operator at the beginning/end of a subexpression, execution terminated *** PION+ Abort called from EXPREV reason INVALID OPERATOR IN SUB-EXPR! Run stopped! STOP INVALID OPERATOR IN SUB-EXPR!
Is there a way to avoid this kind of problem?