how to kill electrons exiting the target

Dear Fluka users,

My question could sound a bit un-physical, but I am simulating something
unusual for Fluka and according to me this is the only way to have some
reasonable results.
I have a beam of electrons interacting with a target and as results I
obtain a beam of photons and electrons exiting the target. I would like
to kill all the electrons exiting the target, but without killing any
electrons eventually generated elsewhere (i.e. by interaction of the
photon beam with something along the beam line). Is this possible?
I think I cannot use the biasing card, not only because using W(1)=2,
I would select a bias for electrons, photons and positrons (instead I
want to kill only electrons), but also because: if I use W(1)>0, i.e. a
bias in a particular region (in my case the vacuum region outside the
target), the other regions wouldn't see that I killed the electrons in
the vacuum region, and if I used W(1)<0, i.e. a bias in all regions,
this bias would effect also the electrons produced by the photons. Is
what I've written correct or have I misunderstood the way bias functions
work?
The other solutions I could think of would be separating photons and
electrons directly at the exit of the target, writing a file with the
characteristics of the photon beam and then using this file as a source
for the simulation of the other objects along the beam line, but I was
wondering whether there is a quicker way to obtain the same result.

Many thanks in advance for any suggestions,
Francesca

Francesca Fiorini
Medical Physics Group,
School of Physics and Astronomy,
University of Birmingham,
Edgbaston Park Road,
B15 2TT,=20
Birmingham,
UK
Received on Fri May 06 2011 - 16:35:15 CEST