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The absorbed doses in the TLDs are estimated scoring the energy deposited in virtually superimposed cartesian grids. This is accomplished by means of the USRBIN cards. The position of these grids as well as the dimensions of the elementary cells are chosen in such a way as to reproduce faithfully the TLD matrices used in the experiment. As can be learned from the FLUKA manual, the accurate binning algorithm for energy deposition is invoked. This means that a charged particle deposits in every bin traversed by the step a fraction of energy proportional to the respective chord (track-length apportioning). In this way statistical convergence is much faster.

The results of our scoring are expressed in GeV/cm³ per electron at atmospheric pressure. We remind you once again that in order to obtain doses in Gy per electron at the operating pressure of the machine, they must be multiplied by 1.60·10^–7/ρ, where ρ is the TLD density (2.64 g/cm³), and rescaled with the pressure. The multiplication may be done off-line by an analysis program. Alternatively, in a more elegant way, the multiplication can be performed on line, at the time of scoring, by adapting and linking one of the user routines: comscw.f.

*
      DOUBLE PRECISION FUNCTION COMSCW(IJ,XA,YA,ZA,MREG,RULL,LLO,ICALL)

      INCLUDE '(DBLPRC)'
      INCLUDE '(DIMPAR)'
      INCLUDE '(IOUNIT)'
*
*----------------------------------------------------------------------*
*                                                                      *
*     Input variables:                                                 *
*                                                                      *
*           Ij = (generalized) particle code                           *
*     Xa,Ya,Za = position                                              *
*         Mreg = region number                                         *
*         Rull = amount to be deposited                                *
*          Llo = particle generation                                   *
*        Icall = call id                                               *
*                                                                      *
*     Output variables:                                                *
*                                                                      *
*       Comscw = factor the scored amount will be multiplied by        *
*       Lsczer = logical flag, if true no amount will be scored        *
*                regardless of Comscw                                  *
*                                                                      *
*     Useful variables (common SCOHLP):                                *
*                                                                      *
*     Energy/Star binnings/scorings (Comscw):                          *
*          ISCRNG = 1 --> Energy density  binning                      *
*          ISCRNG = 2 --> Star   density  binning                      *
*          ISCRNG = 3 --> Residual nuclei scoring                      *
*          JSCRNG = # of the binning                                   *
*                                                                      *
*     Useful variables (common SOUEVT):                                *
*                                                                      *
*          X,Y,Zsoevt(i) = position    of the i_th source particle     *
*          TX,Y,Zsoev(i) = direction   of the i_th source particle     *
*              Wtsoev(i) = weight      of the i_th source particle     *
*              Pmsoev(i) = momentum    of the i_th source particle     *
*              Tksoev(i) = kin. energy of the i_th source particle     *
*              Agsoev(i) = age         of the i_th source particle     *
*              Aksoev(i) = Kaon ampl.  of the i_th source particle     *
*              Ussoev(i) = user var.   of the i_th source particle     *
*              Ijsoev(i) = identity    of the i_th source particle     *
*              Nrsoev(i) = region      of the i_th source particle     *
*              Nlsoev(i) = lattice     of the i_th source particle     *
*                Npsoev  = number of the source particles              *
*                                                                      *
*                                                                      *
*----------------------------------------------------------------------*
*
      INCLUDE '(MAPA)'
      INCLUDE '(SCOHLP)'
      INCLUDE '(SOUEVT)'
*
      LSCZER=.FALSE.
      COMSCW=ONEONE
* ======== In order to compute doses ========= *
*     (Medium(n) is the material number of region n
*      Rho(m) is the density of material m)
      IF ( ISCRNG .EQ. 1 ) COMSCW = 1.6 D-07 / RHO (MEDIUM(MREG))
      RETURN
      END

We remind you here that, in order to activate the call to comscw, an USERWEIG directive must be issued with WHAT(6) > 3.0 (this is not done in the example file presented here). Binning informations are accessible through the SCOHLP common. More detailed informations are reported in the FLUKA manual ("How to write, compile and link a user routine").

Giuseppe Battistoni; INFN, Milano
Alberto Fassò; SLAC, California

Last updated: 10th of October, 2008