Re: [fluka-discuss]: Heavy Ion collision using DPMJET in FLUKA framework

From: Sourav Tarafdar <Sourav.Tarafdar_at_weizmann.ac.il>
Date: Wed, 19 Nov 2014 07:10:53 +0000

Dear Francesco,
  Eventually I can extract the kinematic information of particles in FLKSTK . It will be helpful if you please confirm whether the steps followed by me is in order.

1) Customizing usrein.f routine involves adding following lines in the routine
        INCLUDE '(FLKSTK)’
INTEGER:: ii
DO ii = 1, NPFLKA
        WRITE(LUNOUT, *) Iloflk(ii), Pmoflk(ii), Loflk(ii), Zflk(ii)
ENDDO
2) Compiling usrein.f :
$FLUPRO/flutil/fff usrein.f generates usrein.o

3) Creating executable with link to DPMJET-III generator :
$FLUPRO/flutil/ldmqmd -o executable_name -m fluka usrein.o

4)Running Fluka
      $FLUPRO/flutin/rfluka -e executable_name input_file

So now I am getting the particle kinematics information in my standard fluke output file. It will be helpful if you please confirm whether this is the right way to extract the kinematic information of the particles and nuclear remnants from beam after H.I. collision. Further I have few questions.

1) So far I didn’t see any variable to distinguish between spectator fragments and produced particles in Heavy Ion collision for FLKSTK. Can you please tell me whether there is any tag to distinguish between spectator fragments and produced particles ? If not will it be more appropriate to look at contents of FHEAVY which will most probably will contain spectator fragments ? But somehow I am worried that FHEAVY don’t provide the information of free protons and neutrons as it works from deuteron ?

2) In the output for FLKSTK I noticed some of the particles had ID "-6214308 “ or is short having 7 digits. What are these particles ?


Thanks
-Sourav

On Nov 17, 2014, at 7:02 PM, Sourav Tarafdar <Sourav.Tarafdar_at_weizmann.ac.il<mailto:Sourav.Tarafdar_at_weizmann.ac.il>> wrote:

Dear Francesco,

Thanks for your help. Eventually it is running without any crash. However I am still stuck at retrieving the kinematic information of particles and nuclear fragments remained after H.I. collision. As per your suggestion I needed to look at the FLKSTK content by adding INCLUDE (FLKSTK) in usrein.f routine. However I am not sure which scoring card I need to use in my fluke inout file for dumping out FLKSTK variables ? Further I am wondering if in FLUKA no scoring card exist which can dump out FLKSTK variables in output file then shall I have to customize usreou.f routine specifically for that purpose ?

I have another confusion. Looking at FLUKA user manual it says if primaries are loaded by input option “BEAM” then there is one source particle per event. In my case as I am using “BEAM” for defining type of beam , so I am wondering whether the FLKSTK will store only my colliding beam kinematic information or also all the particles and nuclear remnants from H.I. collision ?

It will be really helpful if I get step by step procedure to extract the kinematic information of particles and nuclear fragments remained after H.I. collision.

Thanks
-Sourav


On Nov 13, 2014, at 11:43 PM, Francesco Cerutti <Francesco.Cerutti_at_cern.ch<mailto:Francesco.Cerutti_at_cern.ch>> wrote:


Dear Sourav,

i. your previous crash is due to the fact that your colliding nuclei are ... not colliding, since in SPECSOUR you input the same lab momentum for both, whereas they should have opposite direction (i.e. negative z-component for one of the two).

ii. Then please note that SPECSOUR requires the total momentum, while HEAVYION in the BEAM card requires momentum or kinetic energy per nucleon (in fact per nuclear mass unit). Moreover, in the presence of SPECSOUR, the only relevant parameters in BEAM are the particle species and the energy/momentum, with the latter just used for transport initialization purposes (the upper limit of stopping power tabulations is defined based on it).

iii. You do not need EVENTYPE (obsolete), IONTRANS (ion transport and interaction already on by default for HEAVYION beams), nor the DPMJET card (whereas you obviously have to use - as I believe you are doing - an executable where dpmjet is linked, like flukadpm3 generated by the ldpmqmd script). You need instead a PHYSICS card with SDUM=LIMITS, specifying an upper threshold for nucleon CMS momentum (110 GeV/c is fine for your case). Standard USERDUMP is not an useful option here.

iv. Note also that the simulated Au-Au collisions are nuclear non-elastic reactions, disregarding electromagnetic dissociation (which has a much higher cross section, but in the present release is not yet available for source collisions).

v. Your XYP plane is useless since you set it exactly upon the RPP downstream face, this way your regAu4 is empty (i.e. has got zero volume). The two VACUUM ASSIGNMA are odd, since the first in fact applies only to regAu4 (FROM regAu4 TO regAu3, but the respective region numbers are such as 2[regAu3] < 3[regAu4]) and the second anyway redefines the regAu4 material (keeping in mind that this region is meaningless as just said).

vi. Concerning CPU time, a 100GeV/n Au + 100GeV/n Au event takes on my machine a bit more than half a second, so 1E5 collisions require less than 20 hours of CPU, i.e. less than 2h on 10 cores, which looks to me as a reasonable time.

Kind regards

Francesco

**************************************************
Francesco Cerutti
CERN-EN/STI
CH-1211 Geneva 23
Switzerland
tel. ++41 22 7678962
fax ++41 22 7668854

On Mon, 10 Nov 2014, Sourav Tarafdar wrote:

Dear Fluka experts,
In continuation of the problem I came up with couple of days ago I want to add few more
things. After removing “SPECSOUR” card from my input file while keeping DPMJET physics
process and executing FLUKA after linking DPMJET to it , “core dump” problem got removed.
So basically the input file is with just unidirectional Au beam with momentum of
100GeV/nucleon. For p+p collision by keeping “SPECSOUR” card it takes forever to finish
even 1 FLUKA cycle. Is it some limitation regarding SPECSOUR card for invoking heavy ion
collision or something related to it is missing in my input file ? I am hereby attaching
my input file. The collision vertex is defined in vacuum within +/- 0.001 cm along X-Y-Z
coordinate and it has been divided into upstream and downstream along Z axis by XYP cut
plane.
Thanks
-Sourav
On Nov 9, 2014, at 12:44 PM, Sourav Tarafdar <Sourav.Tarafdar_at_weizmann.ac.il<mailto:Sourav.Tarafdar_at_weizmann.ac.il>> wrote:

    Dear Francesco,
 Thanks for the suggestions. I implemented your suggestions as far as defining the
collision vertex is concerned , i.e., inclusion of BEAM card and HI-PROPE card on
top of SPECSOUR card. Also I removed Au material region relevant for my collision
vertex. However I got the error on my terminal which looks like
======================= Running FLUKA for cycle # 1 =======================
$FLUPRO/flutil/rfluka: line 359: 13280 Floating point exception(core dumped)
"${EXE}" < "$INPN" 2> "$LOGF" > "$LOGF"
Just wondering whether I am missing something in my input file ? My error file and
output file are completely empty.
Thanks
-Sourav
On Nov 9, 2014, at 12:28 AM, Francesco Cerutti <Francesco.Cerutti_at_cern.ch<mailto:Francesco.Cerutti_at_cern.ch>> wrote:

    Dear Sourav,

          1) Shall I have to define Target region of Au material at
          collision vertex
           ?

    not at all (unless your collisions are supposed to take place in gold
    instead of vacuum...). You defined the second beam species in the
    SPECSOUR card, where you have also said that your first beam is made by
    HEAVYIONs. So you need a HI-PROPE card to specify the HEAVYION nature.
    And you still need a BEAM card (where you shall put HEAVYION - making
    redudant your SPECSOUR WHAT(11) setting - and an energy per nucleon
    exceeding 100 GeV/n for transport initialization purposes).

          2) Which scoring card should be used in order to retrieve
          kinematic
          information of produced particles and nuclear remnants
          after H.I. collision
          ? So far I have used ???USRYIELD??? card.

    USRYIELD does not work yet for the SPECSOUR collision event. You can
    inspect the properties of the products by customizing the usrein.f
    routine - which is automatically called before source particles start
    to be transported - in order to look at the FLKSTK content (to this
    purpose remember to add the
         INCLUDE '(FLKSTK)'
    statement).

    Cheers

    Francesco

    **************************************************
    Francesco Cerutti
    CERN-EN/STI
    CH-1211 Geneva 23
    Switzerland
    tel. ++41 22 7678962
    fax ++41 22 7668854

    On Sat, 8 Nov 2014, Sourav Tarafdar wrote:

          Dear Fluka users,
            I have been trying to simulate Au+Au collision at C.M.
          energy of 200
          GeV/nucleon using DPMJET3 within FLUKA framework. For
          defining the colliding
          beam I used SPECSOUR card with PPSOURCE type. I am mostly
          interested in
          getting the kinematic variables (px, py, pz, energy , pid
          etc) of the
          particles after the collision and also the remnants of the
          nuclei after
          collision. My questions are
          1) Shall I have to define Target region of Au material at
          collision vertex
           ?
          2) Which scoring card should be used in order to retrieve
          kinematic
          information of produced particles and nuclear remnants
          after H.I. collision
          ? So far I have used ???USRYIELD??? card.
          Any suggestions will be of great help.
          Please find the attached input file for FLUKA and the
          output file after
          executing FLUKA using the command $FLUPRO/flutil/rfluka -e
          flukadpm3 test
          Any suggestions will be of great help.
          Thanks
          -Sourav
<fluka_dpm_wotarg.inp>
Received on Wed Nov 19 2014 - 09:50:38 CET

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