[fluka-discuss]: my mgdraw output and fluka standart output are different ?

From: babintsev <babintsev_at_ihep.ru>
Date: Thu, 25 Apr 2019 13:38:50 +0300

Hello,

  I use my mgdraw subroutine to analyze time distributions
of neutrons entering into a selected region.
  I use P beam, Ekin = 1.35 , analyze flux at 90 degree to the beam.

  Question-1:

    - I compare time distributions in the selected region
      in my output for neutrons and output of USRYIELD card:

---
USRYIELD       1399.   NEUTRON      -33.      Rbox RW          Nc2
USRYIELD          5.     1E-14       24.3.14159265 0.0        3. &
*
* **** N time-dist.  target ->  air -> hole  -> count2...
*
USRYIELD       2567.   NEUTRON      -33.      Rbox RW          Nc2Time
USRYIELD          1.     1E-10      100.        5. 1E-14        3. &
     - I use the same bin values as it is given in  33_tab.lis
     - all my T-values are bigger the USRYIELD yield by the factor of 125 !
            ...where is it come from ?!
     - example :
       a) from USRYIELD:
               x1                   x2 N                     er
        3.1622793E-08  3.9810740E-08   924.2861           4.037031
       b) from my output : (value = N observed  / T-bin-width)
               xx
           3.5717e-02                           1.1541e+05
          ...and ratio = 1.1541e+05 /  924.2861 = 124.86 - ?!
          I cannot find any time-information about this in the manual..
       ------------------------------------------
  Question-2:
     - when I compare my output with energy distribution
              using USRYIYLD card  I see the following :
     - I use the same bin distribution as it is done   in 33_tab.lis
     - when I get N neutrons for given bin - I consider it as
       the integral for the bin interval and angle interval : 3.14156
       So, to get USRYIELD output value I have to divide N observed by
           bin interval and angle interval:
             dN/dE dAngle = Nobserved / bin / 3.14156
     - but when I compare it to the values in fluka output :
           I have to use another expression :
             dN/dE * dAngle = Nobserved / bin * 3.14156
       to get the same result !
       why is it so ?
     - example
              x1                         x2 N                er
          1.3490300E-12  1.9761499E-12   19894.96       99.00000
        and my output :
            1.6626e-03                               6.2508e+03
                     19894.96 / 6.2508e+03 = 3.182
  -------------------------------------------------
thank you.
Vladimir
PS. let me know if you need any file
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Received on Thu Apr 25 2019 - 13:51:53 CEST