Crashing due to pho_event.f

Dear FLUKA users,

I am trying to relaunch some simulations that last completed several years ago. After updating a couple of points in the .inp file to comply with the current version of FLUKA, I tried to run it (in flair on WSL/Ubuntu 20), but it crashed with an error that I unfortunately can’t really make sense of.

The magnetic field maps are loaded and the simulation seems to run for a very short time, but then it would crash with a floating point exception noted in the .log file.

The .log file is attached.

lhcb_UPGRADE_MK1_14TeV_19.4.2021_RICH_PEshield001.log (1.6 KB)

The core dump refers to pho_abort.f at pho_event.f:155, which seems to be the following:


    SQS = SQRT((P1(4)+P2(4))**2-(P1(1)+P2(1))**2-
 &     (P1(2)+P2(2))**2-(P1(3)+P2(3))**2)
 &     'PHO_EVENT: Error: Higher energy requested then sqsglobmax.',
 &     SQS,'>', SQSGLOBMAX
    END IF

 !**anfe Safety margin for initialization energy is 20%
         SQSGLOBMAX = 1.2D0*SQRT((P1(4)+P2(4))**2-(P1(1)+P2(1))**2-
      &     (P1(2)+P2(2))**2-(P1(3)+P2(3))**2)

Because of the code seemingly referring to the primary beam parameters, I was suspecting that maybe it also could be connected to the SPECSOUR card. This has changed a bit since I last used it, as I noticed an addition of a second continuation card since my last runs.

For the slim chance that this might have to do with my problem, regarding the new options in flair I’d also like to ask the following:
When using PPSOURCE for actual pp collisions (7+7 TeV, head on pencil beams), with a BEAM and BEAMpos card, do I still have to select the atomic (&mass) number of the second particle (“A:” and “Z:” in flair) or would the default still be a proton?

Also, since flair shows all 3 options of NonElastic, Elastic and EM dissociation as OFF instead of empty/default, do I have to actively select them or does this represent the default described in the manual?

The main cards for my simulation (without geometry) are as follows, please let me know if you need more.
(The full simulation needs several user routines, and magnetic field maps which are loaded via OPEN cards, but I can provide this if needed.)

GLOBAL         5000.                                                  DEPRBODY
OPEN             33.                                                  READONLY
OPEN             34.                                                  READONLY
OPEN             35.                                                  READONLY
OPEN             36.                                                  READONLY
*  Next options are for activation studies
PHYSICS           3.                                                  EVAPORAT
*USERWEIG  only for PMI scoring in combination with modified fluscw.f ic1.f
USERWEIG                              3.                 0.0
PHYSICS           1.                                                  COALESCE
RANDOMIZ         1.0 46852433.
DEFAULTS                                                              PRECISIO
* Calls subroutine mgfld.f
BEAM         10000.0       0.0                                        PROTON
BEAMPOS         0.04     0.001        1.       0.0       0.0
* Magnet UP&DOWN 14TeV pp
SPECSOUR         0.0       0.0    7000.0       0.0       0.0   -7000.0PPSOURCE
SPECSOUR       0.005     0.004       4.1       10.                     &
EMFCUT        -0.001    0.0001   0.00001  BLCKHOLE  @LASTMAT       1.0PROD-CUT
EMFCUT        -0.001    0.0001                  R1  @LASTREG       1.0

Thanks in advance for any help!

Hello @mkaracso ,

it looks like you miss the card PHYSICS with SDUM=LIMITS to correctly initialise DPMJET.

Let us know.
Cheers, Luigi

Hi @luillo

Thank you very much, this seems to have been the last missing piece! A cycle of 10 primaries just completed.

This requirement was new to me, as in the past these simulations ran just fine using DPMJET without this card. I also didn’t stumble across this in the manual.