GEANT321/gphys/gbirk.F

   1 *
   2 * $Id$
   3 *
   4 * $Log$
   5 * Revision 1.1.1.1  1995/10/24 10:21:22  cernlib
   6 * Geant
   7 *
   8 *
   9 #include "geant321/pilot.h"
  10 *CMZ :  3.21/02 29/03/94  15.41.21  by  S.Giani
  11 *-- Author :
  12       SUBROUTINE GBIRK(EDEP)
  13 *
  14 ************************************************************************
  15 *                                                                      *
  16 * *** apply BIRK's saturation law to energy deposition ***             *
  17 * *** only organic scintillators implemented in this version MODEL=1   *
  18 *                                                                      *
  19 * Note : the material is assumed ideal, which means that impurities    *
  20 *        and aging effects are not taken into account                  *
  21 *                                                                      *
  22 * algorithm : edep = destep / (1. + RKB*dedx + C*(dedx)**2)            *
  23 *                                                                      *
  24 * the values of RKB and C can be entered via :                         *
  25 *                                                                      *
  26 * call gstpar(imate,'BIRK1',value) to set the model (must be 1 or 2)   *
  27 * call gstpar(imate,'BIRK2',value) to set RKB                          *
  28 * call gstpar(imate,'BIRK3',value) to set C                            *
  29 *                                                                      *
  30 * the basic units of the coefficient are g/(Mev*cm**2)                 *
  31 * because the de/dx is obtained in Mev/cm                              *
  32 *                                                                      *
  33 * exp. values from NIM 80 (1970) 239-244 :                             *
  34 *                                                                      *
  35 * RKB = 0.013  g/mev*cm**2  and  C = 9.6e-6  g**2/(Mev**2)(cm**4)      *
  36 *                                                                      *
  37 *    ==>Called by : <USER>,GUSTEP                                      *
  38 *       Author    R.Brun , N.Van Eijndhoven    *********               *
  39 *                                                                      *
  40 ************************************************************************
  41 *
  42 #include "geant321/gcbank.inc"
  43 #include "geant321/gcjloc.inc"
  44 #include "geant321/gckine.inc"
  45 #include "geant321/gcmate.inc"
  46 #include "geant321/gctrak.inc"
  47 C.
  48 C.    ------------------------------------------------------------------
  49 C.
  50       EDEP=DESTEP
  51 C
  52 C --- no saturation law for neutral particles ---
  53       IF (ABS(CHARGE) .LE. 1.E-10) GO TO 99
  54 C
  55 C --- get the values for the BIRK coefficients stored via GSTPAR ---
  56       JTMN=LQ(JTM)
  57       IF (JTMN .LE. 0)GO TO 99
  58       MODEL=Q(JTMN+27)
  59       IF(MODEL.GT.2)GO TO 99
  60       RKB=Q(JTMN+28)/DENS
  61       C=Q(JTMN+29)/DENS**2
  62 C
  63 C --- correction for particles with more than 1 charge unit ---
  64 C --- based on alpha particle data (only apply for MODEL=1) ---
  65       IF(MODEL.EQ.1)THEN
  66          IF (ABS(CHARGE) .GE. 2.) RKB=RKB*7.2/12.6
  67       ENDIF
  68 C
  69       DEDXCM=1000.*Q(JLOSS+IEKBIN)
  70 C
  71       EDEP=DESTEP/(1.+RKB*DEDXCM+C*DEDXCM**2)
  72 C
  73   99  RETURN
  74       END
  75