Search found 2137 matches

by Jaakko Leppänen
Fri Jan 24, 2020 4:57 pm
Forum: Users
Topic: Multi-Group Burnup Calculations
Replies: 1
Views: 6

Re: Multi-Group Burnup Calculations

What exactly do you mean by multi group cross sections? The internal routines are based on one energy group. The number of groups makes no difference for the depletion solver since the reaction rates are integrated over all energies.
by Jaakko Leppänen
Tue Jan 21, 2020 5:27 pm
Forum: Users
Topic: macroscopic total fission energy production cross section (dr -8 void)
Replies: 3
Views: 40

Re: macroscopic total fission energy production cross section (dr -8 void)

You have to define the power density using "set powdens" card. If you have the power density fixed, then the problem is most likely related to the material volumes. Serpent cannot calculate the pin volumes in the second case, so the values are initialized to unity. This changes the normalization com...
by Jaakko Leppänen
Tue Jan 21, 2020 5:24 pm
Forum: Manual
Topic: reflection
Replies: 1
Views: 10

Re: reflection

Unfortunately, no.
by Jaakko Leppänen
Mon Jan 20, 2020 6:01 pm
Forum: Users
Topic: macroscopic total fission energy production cross section (dr -8 void)
Replies: 3
Views: 40

Re: macroscopic total fission energy production cross section (dr -8 void)

How do you normalize the results? Do you define the total power or power density?
by Jaakko Leppänen
Wed Jan 01, 2020 11:42 pm
Forum: Gamma transport
Topic: Photon detectors
Replies: 6
Views: 2718

Re: Photon detectors

Using a cell detector (dc option in the cell card) is one way to do it. Serpent doesn't divide the result with volume, so you have to do this manually, or by setting the dv option. If you are looking at dose rates in discrete locations, I recommend you use the super-imposed track-length detector ins...
by Jaakko Leppänen
Wed Jan 01, 2020 11:38 pm
Forum: Users
Topic: Unstructured Mesh Importer and MPI
Replies: 5
Views: 106

Re: Unstructured Mesh Importer and MPI

This warning is related to the calculation of CMM diffusion coefficients. The flux is zero in one of the energy groups (this can happen especially in fast systems). The message will be changed into something more sensible in the next update.
by Jaakko Leppänen
Wed Dec 18, 2019 11:20 pm
Forum: Users
Topic: Hydrogen in Zirconium Hydride and Water with S(a,b) for IFC
Replies: 11
Views: 563

Re: Hydrogen in Zirconium Hydride and Water with S(a,b) for IFC

It looks like the problem is related to the energy boundaries of unresolved resonance probability table sampling, and one unfortunate subroutine that tests them even if the sampling is not on. Try changing the if-statement on line 75 of dopmicroxs.c from: if((RDB[rea + REACTION_XS_I0] > 0) || (E > R...
by Jaakko Leppänen
Wed Dec 18, 2019 4:20 pm
Forum: Users
Topic: Hydrogen in Zirconium Hydride and Water with S(a,b) for IFC
Replies: 11
Views: 563

Re: Hydrogen in Zirconium Hydride and Water with S(a,b) for IFC

Could you send me your input that produces this error? I've worked on the thermal scattering data since July and I could check if this problem has been fixed with the modifications.
by Jaakko Leppänen
Thu Dec 12, 2019 9:15 am
Forum: Bugs, problems, questions & feeback
Topic: Pebble Bed - Segmentation Fault
Replies: 4
Views: 140

Re: Pebble Bed - Segmentation Fault

In your model universe 102 is set as the background universe in the pbed card (the universe that fills the space between the pebbles), but also as the universe that fills each of the two pebbles (in file pbed.inp). However, this universe is not defined anywhere in the input. What you need is: 1) A u...
by Jaakko Leppänen
Thu Dec 12, 2019 9:04 am
Forum: Users
Topic: Unstructured Mesh Importer and MPI
Replies: 5
Views: 106

Re: Unstructured Mesh Importer and MPI

There are no limitations when it comes to parallelization, but if the model is very large, you may eventually run into problems with large memory footprint. One limitation related to group constant generation is that the method works on universes, so the homogenized region has to be represented as a...