Radioactive decay source

Separate section for discussion on gamma transport
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Jaakko Leppänen
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Re: Radioactive decay source

Post by Jaakko Leppänen » Mon Jan 30, 2017 11:09 am

The use of bumat files have several unresolved issues. I recommend use the "set rfw" / "set rfr" features instead:

http://serpent.vtt.fi/mediawiki/index.p ... al#set_rfr
- Jaakko

Peter Wolniewicz
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Re: Radioactive decay source

Post by Peter Wolniewicz » Mon Jan 30, 2017 3:00 pm

Jaakko Leppänen wrote:The use of bumat files have several unresolved issues. I recommend use the "set rfw" / "set rfr" features instead:

http://serpent.vtt.fi/mediawiki/index.p ... al#set_rfr
Thanks this seems to have fixed some issues :)

kaartinen
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Re: Radioactive decay source

Post by kaartinen » Thu Aug 02, 2018 3:55 pm

Hello,
I am having trouble getting decay source working when I am predefining the materials. If I use rfw/rfr from a burn calculation then it does work but not with predefined materials

my code for a really simple case just to test decay source:

Code: Select all

surf s1 cyl 0 0 10 -10 10
surf s2 cube 0 0 0 20
surf s3 cube 15 0 0 2

mat ur -19.0
922340 0.00540
922350 0.72000
922380 99.2700

mat helium -0.2
2000.84p 1

mat steel -7.5
26000.84p 1

cell c1 0 ur -s1
cell c2 0 helium -s2 s3 s1
cell c3 0 steel -s3
cell c4 0 outside s2

set nps 10000

src 1 g sg ur 2
with 2.1.29 version it gives me Input error: Zero emission rate in decay source mode

Is there something I am doing wrong?

Ville Valtavirta
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Re: Radioactive decay source

Post by Ville Valtavirta » Wed Aug 29, 2018 12:30 pm

Hi,

in order for Serpent to calculate the emission rate it needs to know the material volumes. Serpent only tries to calculate them for very simple geometries, e.g. pin-structures. Typically you'll want to supply them manually: http://serpent.vtt.fi/mediawiki/index.p ... al_volumes

In your case the material volume for "ur" is not set, which makes it zero. Calculating emission rate as emission rate density times source volume will yield zero.

We'll add a check for the material volume in a future version to give better error messages in such cases.

-Ville

kaartinen
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Re: Radioactive decay source

Post by kaartinen » Fri Sep 14, 2018 12:45 pm

This worked, thank you!

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