I subscribed to this list but I've not gotten any
direct mailings. Only by reading the web and Will's
forwarding stuff to me.
Regarding David's results...I agree that the 65% in a
DC volume cannot be right. I suspect these are showers
in the torus coils. If you are throwing electrons according
to a Mott cross section without a proper theta cut many of
them will end up in the coils.
SHD1 is part of the mini-torus shielding. The mini-torus and
beamline geometry was completely revamped last year and should
accurately reflect the actual hardware. Please don't disturb it.
Our acceptance is determined by the magnetic field and the trigger
threshold, not by particles running into structures. Its true some
of our triggers arise from electrons scraping things, but these
events do not (hopefully) end up determining our acceptance other
than through simple fiducial cuts.
Therefor, for acceptance studies I would just turn off all the non-detector
geometry, i.e.-
NOGEOM 'FOIL' 'TORU' 'MINI' 'PTG'
At this point GSIM will be dominated by the EC showers. One possibility
is to turn off the EC geometry as well and use the ECHITS bank which
records the particle hits on a plane just in front of the EC module.
Normally these banks are turned off with the card:
NOMC 'EC' 'SC' 'CC' 'DC'
All we really need to know is whether the electron entered the fiducial
area. We can use the MCTK momentum and fudge the energy resolution and
trigger threshold later.
By the way, at UVa we have a 12 node farm of Penitium II 300 MHz Linux
machines that will come on line soon (it is actually available now). I
can start testing some of my rhetoric on this system and try studies that
others may suggest.
Previous work can be found at:
http://apollo.phys.virginia.edu/clas/sim.html
Cole Smith
cole@apollo.phys.virginia.edu