After making the compact.xml, you have to convert to a lcdd file ( for SLIC) and a heprep file (later, for org.lcsim and wired). both can be done using GeomConverter.
The next step is to make a little macro for SLIC to use the particle gun and generate a few events. This is sample:
/lcio/PDGFlag true /generator/select gun /gun/position 0 0 0 /gun/direction 0. 0. 1 /gun/energy 10 GeV /gun/particle neutron /lcio/filename slic_clichcalstack_neutron_10GeV_Wscint.slcio /lcdd/url /home/marcel/demo/stack/clichcalstack.lcdd /run/beamOn 125
The particle Gun is set up as
/generator/select gun /gun/position 0 0 0 /gun/direction 0. 0. 1 /gun/energy 10 GeV /gun/particle neutron
This creates a particle gun and 0/0/0 firing along the z-axis using neutrons at 10 GeV, a list of particles is available in the GEANT manual common examples are gamma, electron, neutron...
/lcio/filename slic_clichcalstack_neutron_10GeV_Wscint.slcio /lcdd/url /home/marcel/demo/stack/clichcalstack.lcdd
this two lines specify the outputfile name and location and the location of lcdd file created with GeomConverterFinally, you decide how many events you want, in this example 125
Start SLIC using
SimDist/scripts//slic.sh -m slic.macro
and off you go