[Solid_tracking] GEM_digitization_validation

[Zhiwen Zhao]

Dear Nilanga

As we talked at the SoLID weekly meeting, here is more info about what's 
needed for the GEM_digitization_validation study
https://hallaweb.jlab.org/wiki/index.php/SoLID_Study#GEM_digitization_validation

The parameters needed to be validated are listed at
https://hallaweb.jlab.org/wiki/index.php/Solid_GEM_Digitization#GEM_response
My guess is some info can be extracted directly without simulation

Here is a copy of current SoLID GEM standalone simulation
https://jlabsvn.jlab.org/svnroot/solid/subsystem/gem/gem_solid_gemc/
It can be taken as an example to build a standalone simulation to match 
GEM test condition
Once we know who will do it.
I can show details and also get an idea about timeline.
By the way, Xinzhan already knew how to run simulation

Thanks

Zhiwen