Summary of main changes between version 1.3 and version 1.4
May 5th 2001

=========Geometry and Kinematics changes========

Dave Gill

 NEW ffcards have been introduced for the user to control various
aspects of a GEANT run.The details of the use of each of these cards is
given below and in the .ffcards file.

 Two of these new cards are used to control the generation of particles
in gukine.F COSM controls the generation of cosmic rays.  SORC controls
the generation of the muon beam (i.e. the source).

 A card DPOL has been introduced which controls the depolarization of
the muons. At present it only allows for the possibility of spin flip
for a stopped muon.
 
 Four other cards are used to control aspects of the geometry for design
studies.
 ROOM controls the atmospheric pressure and temperature of all the gases
in the detector and beamline.
 HEBG installs a helium bag (which by default contains air) between the
end of the beamline and the first detector foil.
 PABR installs a plastice absorber/degrader upstream of the muon
scintillator. Both this plastic degrader and the scintillator are in the
helium bag(HEBG). In addition a scintillator to be employed for positron
timing studies has been installed in the helium bag. This scintillator
is refered to as the t0 scintillator. The size and shape of all
scintillators are controlled in the dt_geo file.
 TECM installs a time expansion chamber as defined by the itams on this
card.
 YOKE has a single entry to allow for not installing the yoke in the
tracking geometry.

 In addition the functions of two of the existing cards have been
modified.
 STPL controls the tracking step length limiting parameters tmaxfd,
stemax, deemax, epsil and stmin. The modification accomodates a second
set of inputs so these parameters can be independently controlled for
the stopping target.
 GABS now controls the type of gas mixture, the length of the gas
absorber and the mixture ratio of the gases in the gas absorber.

============= Monte Carlo data banks ================================

Maxim Vasiliev, Renee Poutissou, Roy Wilds

Data banks containing data known by GEANT have been added to help in
debugging and understanding the analysis program.  Banks 'MCEV' - random
number seed, spin info,
               initial momentum and position for each particle
      'MCWH' - list of wires that have been HIT by a particle 'MCSP' -
      Space point information for every cell traversed
               by a particle

=============Changes to run script===================================

Renee Poutissou

Apart from the "ffcards", the program gets input from files
defined by environment variables:

setenv CHGEOM  $CAL_DB/dt_geo.00014
setenv ISOMAP1 dc_drift_times.00001
setenv ISOMAP2 pc_drift_times.00000
setenv RAYFILE testbeam.dat
setenv TDCMAP1 $CAL_DB/fbc1_map.00007
setenv TDCMAP2 $CAL_DB/fbc2_map.00007

Files dt_geo.00014, fbc1_map.00007 and fbc2_map.00007 have
been substantially changed. These 3 files should normally 
be found in the calibration area $CAL_DB but they have also
been included in CVS in case you do not have an uptodate 
calibration area. 

Output files will be created in directory defined by E614GEANT 
example: setenv E614GEANT ./  selects the current directory
         setenv E614GEANT /twist/data4/renee/  selects a data disk

The output file names are automatically created using the 
run number you have selected in the ffcards.

=================Digitization Changes=============================

Roy Wilds

Digitization is now done at the tracking stage (courtesy of Rob 
Macdonald). 

Hit structures have been re-designed to accomodate new digitization scheme.

The Fast Bus Crate Maps have been altered to accomodate: 
 -Multiplexing of PC wires 1->64 and 97->160 of planes 1->4 and 9->12 
 -Addition of ADCs to PC wires 57->104 of planes 5->8
 -All 4 scintillators are "wired" up to TDCs and ADCs.

The width of a TDC signal is now calculated using the maximum drift time
of a hit, instead of the constant width used in version 1.3

Processing of digitization resolves possible signal overlap in a TDC (due
to multiple hits on a wire, or multiple hits on a group of Multiplexed 
wires).

A TDC window and ADC gate are implemented (set in GUTREV). 

ASCII output of hits data has been altered slightly (due to new digitization
scheme).

DC efficiencies (if turned on) determine if a hit is "seen" by a wire 
(courtesy of Paul Nord).