Optimize Filter Thickness with MCNP5 for Phosphorus 32 Bremsstrahlung

[Addali sabah]

TL;DR

bremsstrahlung simulated by MCNP5

I am working on optimizing the thickness of the filters in order to reduce the continuous Bremsstrahlung spectrum emitted by phosphorus 32 with a maximum energy of 1.8 MeV measured by the Ge(HP) detector using MCNP5 code but unfortunately I don't haven't found the exact form of declaration of bremsstrahlung in the MCNP5 input file, how can I find the correct form of declaration of bremsstrahlung in the MCNP5, and what cards are used for it?. what is the tally to use to get the probability of each energy?

 

[PSRB191921]

Hi,
I'm not sure to understand your problem.
Just transport electrons and photons (mode e p). Your source must be electrons (sdef par=e) and Bremsstrahlung photons will be produced (Bremsstrahlung photons spectrum) and transported.

 

[Addali sabah]

Hi,
I'm not sure to understand your problem.
Just transport electrons and photons (mode e p). Your source must be electrons (sdef par=e) and Bremsstrahlung photons will be produced (Bremsstrahlung photons spectrum) and transported.

thank you but
how can i declare this " Bremsstrahlung photons will be produced (Bremsstrahlung photons spectrum) and transported" in the mcnp5 input file? .is it in phys cards ?

 

[Alex A]

I believe @PSRB191921 's point is that if you put a source of beta rays in a source region made of the same elements your real source is made of, they will interact and produce Bremsstrahlung in same way it happens in the real world. So long as your mode is pe this should happen automatically. If the spectrum is wrong you will need to change the elements in the source to alter it.

If you define a detector region made of Ge, and do an F8:p,e tally, you can set an E8 card with a large number of energy bins around the regions of interest.

 

[Addali sabah]

can you help me to find the mistake in the input file ? Is it this declaration correct for the bremsstrahlung?
this is my input file ( The modeled geometry is composed of the detector( Ge HP) and a parallelepiped source P32 )
1 1 -5.323 (2 :3 )1 -4 -5
2 2 -1.82 -6
3 0 -7 #1 #2
4 0 7

1 pz 0
2 pz 5.1
3 cz 0.6
4 pz 6.1
5 cz 3.025
6 rpp -0.5 0.5 -0.5 0.5 11 11.1
7 so 15

mode p e
m1 32000. 1 $Ge
m2 15032. 1 $P
imp:p 1 2r 0 $ 1, 4
imp:e 1 3r $ 1, 4
sdef PAR=3 ERG=1.7 x=d1 y=d2 z=d3 vec= 0 0 -1 dir=1
si1 -0.5 0.5
sp1 0 1
si2 -0.5 0.5
sp2 0 1
si3 11 11.1
sp3 0 1
nps 1000000
cut:p,e j 0.001
f8:p 1
e8 0 1e-03 120i 1.8
ft8 geb 0.707E-03 0.946E-03
phys:e 2 1 0 0 1 1 1 0 0 0
phys:p 2 0 1 0 1
I want to find the spectrum of phosphorus 32 (bremsstrahlung) and the X-rays from germanium.

 

[Alex A]

Your first line isn't supposed to be a cell line (It might not be, maybe you just didn't copy your title). imp:e is weird you seem to be setting importance to 1 for the void. The source xyz needs setting. You have filled the source with phosphorus 32, which isn't right. It probably has a lot of other things in it, check what it's made of, and very little actual isotope.

I'm still digesting the other stuff.

 

[PSRB191921]

it would be easier to make a sketch of what you want to simulate