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GeneDeitch

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- TL;DR Summary
- MCNP;Brachytherapy

Hello everyone,

I am currently working on a Monte Carlo N-Particle (MCNP) simulation and have encountered several issues that I hope someone here can help me resolve. My project involves simulating a brachytherapy treatment room, and I am struggling with defining the cells, surfaces, and materials correctly. Here are the details of my setup:

Here is the current definition of my materials:

Any guidance on how to resolve these issues would be greatly appreciated. If you need more details or specifics, please let me know.

Thank you in advance for your help!

Best regards

I am currently working on a Monte Carlo N-Particle (MCNP) simulation and have encountered several issues that I hope someone here can help me resolve. My project involves simulating a brachytherapy treatment room, and I am struggling with defining the cells, surfaces, and materials correctly. Here are the details of my setup:

**Room Dimensions**: The treatment room is designed with 75 cm thick concrete walls on all sides. Additionally, there is a 5 cm thick steel shielding within the room.**Door Construction**: The entrance door is composed of 3 cm of wood and 2 cm of plastic.**Environmental Conditions**: The entire room is filled with air.**Water Phantom**: There is a water phantom simulating a person, with dimensions of 178 cm x 70 cm x 25 cm. The radioisotope source is placed at the height of the esophagus, approximately.

Here is the current definition of my materials:

Code:

```
c =========================================================================
c Materials
c =========================================================================
m1 1001 0.10
6000 0.18
7014 0.03
8016 0.65
11023 0.0015
12000 0.0005
15031 0.01
16000 0.0025
17035 0.0015
19039 0.0035
20000 0.015
c Water phantom (simulating a person)
m2 1001 0.011
8016 0.519
11023 0.001
13027 0.019
14000 0.328
20000 0.101
26000 0.021
c Concrete walls
m3 6000 0.00030
14000 0.0020
25055 0.0006
26000 0.7298
28000 0.0900
24000 0.1800
42000 0.00030
c Steel shielding
m4 1001 0.059
6000 0.492
7014 0.001
8016 0.414
16000 0.001
19039 0.001
20000 0.002
12000 0.030
c Wood door
m5 1001 0.14
6000 0.86
c Plastic door
m6 7014 0.7808
8016 0.2095
18000 0.0093
6000 0.00012
c Air
Here are the definitions for the surfaces and cells:
c =========================================================================
c Surfaces
c =========================================================================
1 px 0 $ Surface x = 0
2 px 300 $ Surface x = 300
3 py 0 $ Surface y = 0
4 py 400 $ Surface y = 400
5 pz 0 $ Surface z = 0
6 pz 250 $ Surface z = 250
7 px 75 $ Surface x = 75
8 py 75 $ Surface y = 75
9 py 325 $ Surface y = 325
10 px 225 $ Surface x = 225
c
c Steel shielding (5 cm)
11 px 80 $ Surface x = 80
12 py 80 $ Surface y = 80
13 py 320 $ Surface y = 320
14 px 220 $ Surface x = 220
15 pz 255 $ Surface z = 255
c
c Water phantom (178 cm x 70 cm x 25 cm)
16 px 150 $ Surface x = 150
17 px 328 $ Surface x = 328
18 py 200 $ Surface y = 200
19 py 270 $ Surface y = 270
20 pz 25 $ Surface z = 25
c
c Door construction (5 cm total: 3 cm wood + 2 cm plastic)
21 px 72 $ Surface x = 72 (wood)
22 px 75 $ Surface x = 75 (entire door)
23 px 77 $ Surface x = 77 (plastic)
24 py 5 $ Surface y = 5
25 py 80 $ Surface y = 80
c
c =========================================================================
c Cells
c =========================================================================
2 2 -2.3 -1 2 -3 4 -5 6 imp:p=1 $ Concrete walls (75 cm)
3 3 -7.86 -11 12 -13 14 -5 6 imp:p=1 $ Steel shielding (5 cm)
4 1 -1.0 -16 17 -18 19 -20 imp:p=1 $ Water phantom (simulating a person)
5 4 -0.64 -21 22 -24 25 imp:p=1 $ Wood door (3 cm)
6 5 -1.406 -22 23 -24 25 imp:p=1 $ Plastic door (2 cm)
7 6 -0.0012 -7 2 -3 4 -5 6 #2 #3 #4 #5 imp:p=1 $ Air in the room
999 0 #2 #3 #4 #5 #6 imp:p=0 $ Rest of the universe (vacuum)
```

Thank you in advance for your help!

Best regards

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