Search found 361 matches

by Ville Valtavirta
Fri Dec 13, 2019 9:09 am
Forum: Users
Topic: Sensitivity Analysis Issues
Replies: 4
Views: 156

Re: Sensitivity Analysis Issues

What do you exactly mean by "restart file" in this context? You could simply re-run the simulation with a different random number seed and average the results over multiple simulations. The sensitivity calculations do not really contain any "history data" that would need to be written to a restart f...
by Ville Valtavirta
Mon Dec 09, 2019 2:33 pm
Forum: Users
Topic: Sensitivity Analysis Issues
Replies: 4
Views: 156

Re: Sensitivity Analysis Issues

Hi, the increase in memory demand comes from the fact that Serpent needs to keep track of events that happen to each simulated particle during the transport over many particle generations. There are a couple of ways to decrease the memory consumption: The memory demand scales with the number of neut...
by Ville Valtavirta
Mon Dec 09, 2019 2:20 pm
Forum: Users
Topic: Fatal error in function SamplePointDelnu:
Replies: 2
Views: 108

Re: Fatal error in function SamplePointDelnu:

Hi,

a fix for this bug is detailed in this post: viewtopic.php?f=15&t=3266&p=10207#p10212

-Ville
by Ville Valtavirta
Mon Nov 25, 2019 5:18 pm
Forum: Users
Topic: Treatment of reflective boundaries in Serpent
Replies: 3
Views: 150

Re: Treatment of reflective boundaries in Serpent

Hi, this seems to be a bug with some nuclides that have a threshold energy for the fission reaction. Normally, the emission energy and direction for the delayed neutron are sampled from the ENDF law at the incoming neutron energy of 1 eV. Some fission reactions have a threshold energy higher than 1 ...
by Ville Valtavirta
Wed Nov 13, 2019 2:06 pm
Forum: Bugs, problems, questions & feeback
Topic: Input error: Continuous S(a,b) format not supported
Replies: 9
Views: 851

Re: Input error: Continuous S(a,b) format not supported

Thank you Paul,

we'll look into implementing the support.

-Ville
by Ville Valtavirta
Wed Nov 13, 2019 2:03 pm
Forum: Users
Topic: Treatment of reflective boundaries in Serpent
Replies: 3
Views: 150

Re: Treatment of reflective boundaries in Serpent

Hi, Serpent does not support reflective surfaces like MCNP does, so you are limited to Reflective boundary conditions at geometry outer boundary set bc . Universe symmetries using a symmetry angle/wedge set usym . The first option is typically useful only if the unit cell of the repeated structure i...
by Ville Valtavirta
Wed Nov 13, 2019 12:56 pm
Forum: Compiling and installing Serpent
Topic: Compiling Serpent 2.1.31 with OpenMP: issue with gcc 9
Replies: 1
Views: 92

Re: Compiling Serpent 2.1.31 with OpenMP: issue with gcc 9

Thank you Paul for reporting this,

it seems a quick fix for this is to move from default(none) on line 60 of the file to default(shared).

I'll have to test the change once I get my hands on gcc 9.

-Ville
by Ville Valtavirta
Wed Oct 16, 2019 5:22 pm
Forum: Users
Topic: Large burnup MPI memory problem
Replies: 5
Views: 181

Re: Large burnup MPI memory problem

Thanks for reporting.

We'll have to keep this in mind and maybe add some details to the Wiki.

-Ville
by Ville Valtavirta
Tue Oct 15, 2019 9:12 pm
Forum: Users
Topic: Large burnup MPI memory problem
Replies: 5
Views: 181

Re: Large burnup MPI memory problem

I haven't used PBS myself but to me it seems that you are requesting 8 nodes but creating 10 MPI tasks?

This would mean that some nodes get two tasks and thus a doubled memory consumption.

-Ville
by Ville Valtavirta
Fri Oct 11, 2019 4:29 pm
Forum: Users
Topic: graphics library
Replies: 1
Views: 91

Re: graphics library

Hi,

at least on Ubuntu 18.04 installing the libgd-dev package seems to do the trick.

-Ville