MCNP5 error: Source distribution in 2 volumetric cells (help please)

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SUMMARY

The forum discussion centers on resolving a fatal error encountered while simulating source distribution in two volumetric cells using MCNP5. The user aimed to distribute a photon source of 356 keV between two cells, with 20% in cell 30 (thyroid without nodule) and 80% in cell 31 (nodule). The error messages indicated issues with source distribution lengths and unused distributions. The problem was resolved by correcting the syntax from "DS8 9 10" to "DS8 S 9 10".

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DePaco
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Hello,
can you help me? In my model, I have to simulate source distribution in two volumetric cells (30 and 31). For example, with a photon source of 356 keV, I have to simulate the distribution according 0.2 (20% in source 30: thyroid without nodule) and 0.8 (80% in source 31: nodule). I use MCNPprimer Script (page 14-15) but I have an error.
Fatal Error :
fatal error. dependent distribution 8 is the wrong length.
warning. source distribution 9 is not used in this problem.
warning. source distribution 10 is not used in this problem.
My code is :
C Cellules
30 50 -1.00 (-1 3 19):(-2 3):(-4 3 -6 5 -7 1 2) imp:p=1 $lobe eau ND
c 31 50 -1.00 -19 3 imp:p=1 $Nodule eau
31 50 -1.00 -19 3 #(-4 3 -6 5 -7 1 2) imp:p=1 $Nodule eau
c 31 55 -3.67 -19 3 #(-4 3 -6 5 -7 1 2) imp:p=1 $Nodule NaI
32 51 -1.19 -8 -9 #((-1 3):(-2 3):(-4 3 -6 5 -7 1 2):(-19 3)) imp:p=1 $cou PMMA
33 52 -2.7 -10 11 imp:p=1 $Cyl Alu
34 53 -1.2e-3 (-11 -13):-16:-18 imp:p=1 $Cyl int air
35 51 -1.19 -11 13 -14 12 imp:p=1 $PMMA
36 54 -3.58 -11 14 imp:p=1 $MgO
37 55 -3.67 -12 imp:p=1 $Cyl NaI
38 56 -11.35 -15 16 imp:p=1 $Cyl Pb
39 57 -7.87 -17 18 imp:p=1 $Inox (Fer)
40 53 -1.2e-3 -20 #(-8 -9) 10 15 17 imp:p=1 $monde air
80 0 20 imp:p=0 $vide

C Structures
c Thyroide
1 SQ 0.982 0.982 0.171 0 0 0 -1 1.4122 0 0 $lobe droit
2 SQ 0.982 0.982 0.171 0 0 0 -1 -1.4122 0 0 $lobe gauche
3 CZ 1.009 $Cyl Trachee
4 CZ 1.412 $Cyl Isthme
5 PZ -2.017 $Plan Isthme bas
6 PZ 0 $Plan Isthme haut
7 PY 0 $Plan Trachee
8 RCC 0 3.528 -3 0 0 6 5.4 $Cyl cou
9 PY 1.412 $Plan cou
c Detecteur NaI
10 41 RCC 0 0 0 0 3 0 2.85 $Cylindre ext
11 41 RCC 0 0.04 0 0 2.92 0 2.81 $Cylindre int
12 41 RCC 0 0.18 0 0 2.54 0 2.54 $NaI
13 41 PY 0.18 $Plan NaI bas
14 41 PY 2.72 $Plan NaI haut
15 41 RCC 0 3 0 0 1 0 2.85 $Cyl Pb ext
16 41 RCC 0 3 0 0 1 0 2.35 $Cyl Pb int
17 41 RCC 0 4 0 0 0.32 0 2.85 $Cyl Inox ext
18 41 RCC 0 4 0 0 0.32 0 2.64 $Cyl Inox int
c Taille des nodules
19 S 1.77 0 0 0.2 $Nodule lobe droit D=0.4 cm
20 SO 80 $monde

C Reste
c deplacement nodule
c tr42 1.4122 0 0
c deplacement detecteur
tr41 0 -6.192 0 $DDC=0cm
c tr41 0 -21.192 0 $DDC=15cm
c tr41 0 -36.192 0 $DDC=30cm
mode p
c eau
m50 1000 2
8000 1
c PMMA
m51 1000 -0.080541
6000 -0.599846
8000 -0.319613
c Aluminium
m52 13000 1
c Air
m53 6000 -0.000124
7000 -0.755268
8000 -0.231781
18000 -0.012827 $ air
c MgO
m54 12000 -0.603036
8000 -0.396964
c NaI
m55 11000 -0.153373
53000 -0.846627
c Plomb
m56 82000 1
c Inox (Fer)
m57 26000 1
c Fixation nodulaire et tissus sains
c SDEF PAR=2 ERG=0.356 CEL d1 AXS=0 0 1 POS 0 0 0 RAD d2 EXT d5
c eff=0.001
c SI1 30 31
c SP1 D 0.2 0.8
c SI2 0 2.5
c SI5 -2.5 2.5
c Definition des paramètres uptake
SDEF PAR=2 CEL=d1 POS=FCEL d2 AXS=0 0 1 RAD=FCEL d5 EXT=FCEL d8 ERG=FCEL d20
c Choix des cellules et leur uptake
SI1 L 30 31
SP1 0.2 0.8
c Position centrale du cylindre englobant chaque source
DS2 S 3 4
SI3 L 0 0 0
SP3 1
SI4 L 1.77 0 0
SP4 1
c Rayon du cylindre englobant chaque source
DS5 S 6 7
SI6 0 2.5
SP6 -21 1
SI7 0 0.5
SP7 -21 1
c Limite inférieure et supérieure de chaque cylindre
DS8 9 10
SI9 -2.5 2.5
SP9 -21 0
SI10 -0.5 0.5
SP10 -21 0
c Energie des photons de chaque source
DS20 S 21 22
SI21 L 0.356
SP21 D 1
SI22 L 0.356
SP22 D 1
F8:p 37
e8 0.0 1e-4 0.320 100i 0.370
nps 1e6Thank you for your help.
 
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Hi,
You write DS8 9 10
Instead of DS8 S 9 10
PSR
 
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Thank you. I have solved my problem.
 

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