FLUKAFIX

     Sets the size of the step of muons and charged hadrons to a fixed
     fraction of the kinetic energy in different materials

     See also EMFFIX, MULSOPT, STEPSIZE

     
WHAT(1)
 = fraction of the kinetic energy to be lost in a step
               (cannot be > 0.2)
               
Default
: if option DEFAULTS is used with 
SDUM
 = ICARUS, the
                        default is 0.02.
                        With 
SDUM
 = HADROTHErapy or PRECISIOn, the default
                        is 0.05.
                        If 
SDUM
 = CALORIMEtry, the default is 0.08.
                        With any other 
SDUM
 value, or if DEFAULTS is missing,
                        the default is 0.1.

     
WHAT(2)
 = "epsilon" parameter used to check the finite size of the
               nucleus when the nuclear form factor is not invoked by
               the multiple scattering algorithm (see Note 3 below)
               For code development only, do not change!
               
Default
 = 0.15

     
WHAT(3)
 = high-energy limit for the fraction of energy to be lost
               in a step (the fraction is given by 
WHAT(3)
 times 
WHAT(1)
)
               For code development only, do not change!
               
Default
 = 0.012

     
WHAT(4)
 = lower index bound (or corresponding name) of materials where
               the specified energy loss per step is to be applied
               (From material 
WHAT(4)
...)
               
Default
 = 3

     
WHAT(5)
 = upper index bound (or corresponding name) of materials where
               the specified energy loss per step is to be applied
               (... to material 
WHAT(5)
...)
               
Default
 = 
WHAT(4)

     
WHAT(6)
 = step length in assigning indices
               (...in steps of 
WHAT(6)
)
               
Default
 = 1

     
SDUM
 :   not used

     
Default
 (option FLUKAFIX not given): the defaults listed above apply

    
Notes:
        1) Usually there is no need for changing the general default value of
           10% (0.1) for 
WHAT(1)

* Start_Devel_seq
        2) The input value is actually applied as such only at intermediate
           energies (between about a few tens of MeV and 1 GeV): at low energies
           it is slowly increased to twice the requested value, while at high
           energies it decreases to a limit controlled by 
WHAT(3)
, usually about
           one hundredth of the input value.
        3) The "epsilon" parameter controls the accuracy of the multiple
           scattering algorithm by limiting the step. In most cases the
           length of the step is practically limited anyway by the hadron
           interaction length, so the "epsilon" default value is of little
           importance and does not need to be changed.
           However, in some problems of large dimensions, especially when
           transporting muons, a small value of epsilon can slow down the
           calculations without necessity. In such cases, 
WHAT(2)
 can be
           safely set = 1000.0
* End_Devel_seq
* Start_Prod_seq
        2) The input value is actually applied as such only at intermediate
           energies (between about a few tens of MeV and 1 GeV): at low energies
           it is slowly increased to twice the requested value, while at high
           energies it decreases to a limit usually about one hundredth of the
           input value.
* End_Prod_seq

     Example (number based):

 *...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....
 FLUKAFIX        0.03        0.        0.       21.        0.        0.
 *  The maximum fractional energy loss for hadrons and muons is set to
 *  3 percent in material 21.

     The same example, name-based:

 FLUKAFIX        0.03        0.        0.   CALCIUM        0.        0.

Previous Index Next