FTPC Drift Map Maker


StFtpcDriftMapMaker replaces St_fmg_Maker. It is a standalone program.

StFtpcDriftMapMaker calculates the maps for electron drift in the electric and magnetic field for the STAR Forward TPCs for the magnetic field (FF, HF, ZF, RHF or RF) and gas composition requested by the FtpcDriftMapMaker.C macro. The magnetic field is obtained using StarMagField.

The heart of the code are the algorithms of both magboltz1 and 2. In the standard version, magboltz 1 is used because of the much shorter calculation time.

The baseTemperature, basePressure and pressureOffset parameters come from the Calibrations_ftpc/ftpcGas table in the STAR MySQL offline database.

StFtpcDriftMapMaker is written in C++ by Holm Hümmler and is maintained by Janet Seyboth. To do the gas calculations (actually the bulk of the work), it uses the C++ Magboltz program package, which calculates the drift properties at different points in the FTPC volume.

Magboltz was written by
It is the same program used to calculate electron drift properties in the Garfield field simulation program.

To run StFtpcDriftMapMaker:

    mkdir Work 

    cd Work  

    ln -s StRoot/StFtpcDriftMapMaker/macros/FtpcDriftMapMaker.C FtpcDriftMapMaker.C

    root4star -b -q FtpcDriftMapMaker.C(map,factor,deltaAr) 

map select magnetic field valuesDefault: = 2
= 1 use constant field values
= 2 use mapped field values
factor field scaling factor Default: = 1.0 (full field positive)
> 0.8 full field positive
< 0.8 && > 0.2 half field positive
< 0.2 && > -0.2 zero field
> -0.8 half field negative
< -0.8 full field negative
deltaAr the change (+/-) in the percentage of Ar from 50% Default: = 0.0

FtpcDriftMapMaker.C may take over 20 minutes to run. Upon completion, it will write out the drift map tables:

After testing, these files can be uploaded into the Calibrations_ftpc offline database.

This page was created by Janet Seyboth on January 20, 2001
This page was last updated by Janet Seyboth on Nov 10, 2009