Can the energy deposition by the delayed fission gamma be calculated by Openmc?

[yiyan]

Hi,

I'm now doing some analyses of energy deposition with Openmc and have a theoretical question : 

Does Openmc calculate the energy deposition by the delayed fission gamma when I use the Coupled neutron-photon transport mode?

Thanks.

[Paul Romano]

Yes, this is actually a change that was made recently. By default, the yield of prompt fission gammas is scaled up to account for the energy release corresponding to delayed fission gammas. In this sense, the spectrum is not correct (since the prompt/delayed spectra are different), but at least the delayed energy is accounted for. Note that this behavior can be turned off with Settings.delayed_photon_scaling. This treatment is not in the most recent release (0.11), but is already in the develop branch and will appear in our next release.

Best regards,

Paul

--
You received this message because you are subscribed to the Google Groups "OpenMC Users Group" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openmc-users...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/openmc-users/f46ee84a-6907-4ae8-8aff-caa76ad62036%40googlegroups.com.

[杜亦衍]

Hi Paul,

I met another problem about the calculation of delayed photon sacling.

Following your guide, I downloaded a version with the delayed photon sacling function. (Here is the version I used:

https://github.com/openmc-dev/openmc/tree/a1b8719ae80ba3bd922adb573c8897de93a3510d 

I noticed you've added git_submodules in CMakelist.txt, while without access to Internet in my workstation, I chose this older version.)

I succeeded in the installation and run the test you did in https://nbviewer.jupyter.org/gist/paulromano/89c78dc74d98215a8f2a406753b2215d?force_flush=true

but my results are different with yours (see 02.png) and it seems the delayed photon sacling function didn't work.

I then checked the setting.xml and found the delayed_photon_sacling was actually read (see 01.png).

so I'm really confused...

Hoping you can answer my question, thx

Tianxue

在 2020年3月18日星期三 UTC+1下午3:13:01，Paul Romano写道：

Yes, this is actually a change that was made recently. By default, the yield of prompt fission gammas is scaled up to account for the energy release corresponding to delayed fission gammas. In this sense, the spectrum is not correct (since the prompt/delayed spectra are different), but at least the delayed energy is accounted for. Note that this behavior can be turned off with Settings.delayed_photon_scaling. This treatment is not in the most recent release (0.11), but is already in the develop branch and will appear in our next release.

Best regards,

Paul

On Wed, Mar 18, 2020 at 7:18 AM yiyan <duyiy...@gmail.com> wrote:

Hi,

I'm now doing some analyses of energy deposition with Openmc and have a theoretical question : 

Does Openmc calculate the energy deposition by the delayed fission gamma when I use the Coupled neutron-photon transport mode?

Thanks.

--
You received this message because you are subscribed to the Google Groups "OpenMC Users Group" group.

To unsubscribe from this group and stop receiving emails from it, send an email to openmc...@googlegroups.com.

To view this discussion on the web visit https://groups.google.com/d/msgid/openmc-users/f46ee84a-6907-4ae8-8aff-caa76ad62036%40googlegroups.com.

在 2020年3月18日星期三 UTC+1下午3:13:01，Paul Romano写道：

Yes, this is actually a change that was made recently. By default, the yield of prompt fission gammas is scaled up to account for the energy release corresponding to delayed fission gammas. In this sense, the spectrum is not correct (since the prompt/delayed spectra are different), but at least the delayed energy is accounted for. Note that this behavior can be turned off with Settings.delayed_photon_scaling. This treatment is not in the most recent release (0.11), but is already in the develop branch and will appear in our next release.

Best regards,

Paul

On Wed, Mar 18, 2020 at 7:18 AM yiyan <duyiy...@gmail.com> wrote:

Hi,

I'm now doing some analyses of energy deposition with Openmc and have a theoretical question : 

Does Openmc calculate the energy deposition by the delayed fission gamma when I use the Coupled neutron-photon transport mode?

Thanks.

--
You received this message because you are subscribed to the Google Groups "OpenMC Users Group" group.

To unsubscribe from this group and stop receiving emails from it, send an email to openmc...@googlegroups.com.

[Paul Romano]

Tianxue,

Note that delayed photon scaling is on by default, so setting it to true won't appear to have any effect compared to just omitting it. The option is there in case a user doesn't want to include that effect (setting it to false). One other change that we've made recently is that when you run a calculation with photons, energy deposition can be attributed to photons, electrons, and positrons individually. So, to get the total energy deposition, if you are using a particle filter you'll want to make sure you include 'electron' and 'positron' as well. Most of the energy deposition is actually due to electrons that are produced from photon reactions.

Best,

Paul

To unsubscribe from this group and stop receiving emails from it, send an email to openmc-users...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/openmc-users/8eb03816-9dd9-40e6-9c1d-7fd64d5d3779%40googlegroups.com.