FTPC Drift Map Generator

FMG - FTPC Drift Map Generator

calling parameters:

fmg_(
fcl_det_h, fcl_det,	geometry and runtime parameters for fcl (parameters)
fcl_padtrans_h, fcl_padtrans,	ExB drift table, to calculate (parameter output)
fcl_zrow_h, fcl_zrow,	z positions of all padrows (parameters)
fmg_fmgpar_h, fmg_fmgpar)	parameters for drift table calculation (parameters)

FMG automatically recalculates the drift and ExB distortion map for the STAR Forward TPCs from parameters like gas composition, drift voltage and temperature. The magnetic field is taken from the gufld stored with the data processed in the current chain.

The FTPC drift map generator is implemented in root as a pam via its own wrapper, St_fmg_Maker.

The main fmg routine is written in C by Holm Hümmler. However, to do the gas calculations (actually the bulk of the work), it uses the Magboltz program package, in the form of Fortran routines which are called to calculate the drift properties at different points in the FTPC volume.

Magboltz was written by DR.S.F.BIAGI, PHYSICS DEPARTMENT, UNIVERSITY OF LIVERPOOL, LIVERPOOL, U.K. It is the same program used to calculate electron drift properties in the Garfield field simulation program.

To run fmg, replace St_fcl_Maker with St_fmg_Maker in your chain and start only one event (get a cup of coffee...). Then write out the new StDb/params/ftpc/fclpars/padtrans.C, with a macro like StRoot/macros/examples/SavePrimitive.C.

This page was updated by Holm Hümmler on July 29, 1999