Re: [fluka-discuss]: About the age of the particle in MGDRAW

From: Luigi Salvatore Esposito <>
Date: Fri, 8 Mar 2019 11:40:47 +0000

Dear Qi,

ATRACK gives the time at the end of each step and it is computed from the start of the event.

If you want the time when a photo-neutron as been produced, you need to use USDRAW, activated by WHAT(4) in USERDUMP,
filter on a photo-nuclear interaction (ICODE=101 and JTRACK=7) and check that at least a neutron is among the secondaries.

Attached you can find the mgdraw modified for the scope.

Hope this could help.

Cheers luigi

On 7 Mar 2019, at 16:40,<> wrote:

Dear Fluka experts,
I want to simulate the transport process of electrons being injected into a Ta target and record the data of photoneutrons. With MGDRAW user routine, I can get the age of the neutron by variable ATRACK. But when I modified the MGDRAW.f file as follow: SUBROUTINE MGDRAW ( ICODE, MREG )
      IF ( JTRACK .EQ. 8 ) THEN
     & SNGL (WTRACK)
         WRITE (92,*) ( SNGL (XTRACK (I)), SNGL (YTRACK (I)),
     & SNGL (ZTRACK (I)), I = 0, NTRACK ),
     & ( SNGL (DTRACK (I)), I = 1, MTRACK ),
     & SNGL (CTRACK)
I will get the data as follow(here I only show the data of one neutron for example):
           1 0 8 0.939982057 9.70298983E-03
  0.322248042 6.06961399E-02 5.58620729E-02 -5.55111512E-17 9.48838666E-02 -0.100359999 0.359747052
 -0.895762861 9.50326771E-02 -0.434255302 4.14305951E-10 4
           1 0 8 0.939982057 9.70298983E-03
  -5.55111512E-17 9.48838666E-02 -0.100359999 -79.0000000 8.47609901 -38.3986320 88.1929855
 -0.895762861 9.50326771E-02 -0.434255302 9.92574911E-08 4

These data means that there are two step of this neutron, so 3 point of the path exist. However, there are only two data of the age of the neutron. Why? If I want to get the birth time of neutron, which age is what I need? Is it the first one? If it is ture, what is the age of neutron at the end point of the last step?
Best Regards


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Received on Fri Mar 08 2019 - 14:13:27 CET

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