Monte Carlo digitization

[beni zihlmann <bzihlman@indiana.edu>]

Hi Folks,
I guess this is the correct mailing list to address this topic (probably 
again).

I write down here a few points I gathered while looking into the 
digitization
of the FTOF detector but I am sure most of what I found is also true for 
the
other detector parts. Before any of use can/should implement any 
digitization
of his/her detector we need some clear guide lines otherwise we will do the
work twice or more.

1) currently nothing really is done yet (to my knowledge)

2) the user function GUDIGI.F does not exist (yet). This
   is the logical place to connect all the digitization routines of
   all detectors to. Also in view of a future upgrade to GEANT4.

3) currently some very poor man's energy attenuation etc. is  done
   in the sequence of GUSTEP.F. This is the wrong place to do any
   digitization part. Different hits should not be mixed already at this 
stage.
   Also, hit positions are not stored and other additional information 
maybe
   also needed like parent particle.

4) a lot of hard coded parameters are floating around that should be 
defined
   in a database (could be a simple file) and initialized at the proper 
location
   in the code

5) as we will use FLASH ADCs and Multi-Hit TDCs the exact functionality
   of them and how the readout will work and what exactly is read out is 
crucial
   for the implementation of the digitization. In particular for example 
how will
   the pedestal subtraction be done on the level of the FLASH ADC in a 
FPGA etc. ?

7) the GEANT cutoff parameters for the particles and volumes needs 
attention and
   definitions in the code.

8)  currently the whole MC code resides in almost just one directory. In 
view of the future
    massive increase in code we need a structure that helps us keeping 
an over view.
    9) and many more points I am sure come to your mind that I have not 
mentioned.

All this issues can probably not be solved by e-mail. However we should 
start now collecting
all necessary information and opinions so that we can come to a 
conclusion/guide-lines asap.

Opinions?

cheers,
Beni

-- 

B. Zihlmann
Indiana University
Physics Department
727 E. Third Street
Bloomington, IN 47405
phone: (812) 855 6973
Fax:   (812) 855-5533