Mismatch in photon and proton differential fluence spectra between PHITS and Fluka

Hi, I was ccomputing the neutron, photon, and proton spectra comparison between PHITS and FLUKA for a very simple accelerator geometry. While neutron spectra agreed between two codes, there was a mismatch in photon and proton spectra at low energies (<1 MeV) for photons and higher energies (~100 MeV) for protons. The target I used was Cu and shielding was 1 m thick concrete. The incident beam was 300 MeV/u Ca-48. I am att
Fluka_Input_Geom1.inp (5.9 KB)




aching the input file of Fluka and physics setting for PHITS as well as the graphs.

[ T i t l e ]
Computation of dose map and particle track; Inside and outside a 1 m thick concrete shielding
$OMP=0
[ P a r a m e t e r s ]
icntl = 0 # (D=0) 3:ECH 5:NOR 6:SRC 7,8:GSH 11:DSH 12:DUMP
rseed = -1
maxcas = 1.00E+03 # number of particles per one batch
maxbch = 2000 # (D=10) number of batches
maxbnk = 10000000
mdbatima = 3000
emin(1) = 1.000000000E-03 # (D=1.0) cut-off energy of proton (MeV)
emin(2) = 1.000000000E-10 # (D=1.0) cut-off energy of neutron (MeV)
dmax(2) = 20.0000000 # (D=emin(2)) data max. energy of neutron (MeV)
emin(14) = 1.000000000E-03 # (D=1.d9) cut-off energy of photon (MeV)
dmax(14) = 1000.00000 # (D=emin(14)) data max. energy of photon (MeV)
emin(15) = 1.000000000E-03 # (D=1.d9) cut-off energy of deuteron (MeV)
emin(16) = 1.000000000E-03 # (D=1.d9) cut-off energy of triton (MeV)
emin(17) = 1.000000000E-03 # (D=1.d9) cut-off energy of 3He (MeV)
emin(18) = 1.000000000E-03 # (D=1.d9) cut-off energy of Alpha (MeV)
emin(19) = 1.000000000E-03 # (D=1.d9) cut-off energy of Nucleus (MeV)
esmin = 1.000000000E-06 # (D=0.001) min energy for charged particle range
e-mode = 2 # (D=0) 0: Normal, 1: Event generator mode
itall = 1 # (D=0) 0:no tally at batch, 1:same, 2:different
negs = 1 # (D=0) =1 EGS photon and electron
irqmd = 1 # JQMD-2.0 for nuclear reactions
nspred = 2
nedisp = 1
iMevperU = 1
file(6) = phits.out # (D=phits.out) general output file name
file(7) = C:/phits/data/xsdir.jnd
file(20) = C:/phits/XS/egs

Dear @Rajarshi,

Thanks for your question,

Could you please share me the PHITS input and the results you obtained with both codes?
This might help me to find the reasons of these differences.

Thanks,
André