Search found 18 matches

by Andy_Turner
Mon Sep 19, 2016 1:18 pm
Forum: Parallelization
Topic: Some thoughts on load balancing...
Replies: 1
Views: 1741

Some thoughts on load balancing...

Since development is turning to variance reduction and weight widows, and a few people have asked about 'rendezvous/dump' capability, I just wanted to include my thoughts on some related issues. With MCNP the existing work distribution model is not ideal. Since there is a desire to write restart fil...
by Andy_Turner
Thu Aug 25, 2016 5:29 pm
Forum: General
Topic: Geometry error handling
Replies: 1
Views: 1392

Geometry error handling

Hi Jaakko and colleagues A very basic question on Serpent 2 geometry error handling. I note that, for CSG geometry: 1. if geometry has an undefined region, the simulation will abort when a neutron enters the region. The error is "Cell universe / overlap or undefined cell" 2. if geometry has an overl...
by Andy_Turner
Thu May 05, 2016 5:58 pm
Forum: Input
Topic: Irregular 3D geometries (CAD, etc.)
Replies: 41
Views: 63107

Re: Irregular 3D geometries (CAD, etc.)

Do you mean CAD or mesh-based geometry? With mesh-based geometries you can use the "dumsh" option with detectors: det <name> dumsh <uni> <N> <c1> <b1> <c2> <b2> ... <cN> <bN> where <uni> is the mesh universe. You can list <N> mesh cells (<c1>, <c2>, ... ) which are mapped into <N> detector bins (<b...
by Andy_Turner
Mon Apr 25, 2016 10:04 am
Forum: Development
Topic: Data dump every n cycle
Replies: 3
Views: 17216

Re: Data dump every n cycle

Did this ever happen? This would be useful.

Does it collect detector data from all MPI tasks every 50 cycles?
This would explain why there is more penalty for small batches when using large mesh detectors.
by Andy_Turner
Fri Apr 08, 2016 11:37 am
Forum: Gamma transport
Topic: Photon detectors
Replies: 4
Views: 2597

Re: Photon detectors

Can you confirm the units that come out of photon heating using dr -26 <mat> ? Having performed simple 'thin cell' comparisons with MCNP F4 FM -4 1 / -5 -6 and F6 tallies, I get agreement with the '-200 void' response function which is indeed Gy-cm3/hr per source particle. For neutrons using dr -4 <...
by Andy_Turner
Fri Apr 01, 2016 10:13 am
Forum: Gamma transport
Topic: Gamma detectors and flux to dose
Replies: 37
Views: 4862

Re: Gamma detectors and flux to dose

Serpent allows using user-defined response functions with reaction identifier -100: dr -100 <int> <np> <E1> <f1> <E2> <f2> ... where <int> is the interpolation type used between the points (1 = histogram, 2 = lin-lin, 3 = lin-log, 4 = log-lin, 5 = log-log), <np> is the number of points and <En> <fn...
by Andy_Turner
Thu Mar 31, 2016 2:11 pm
Forum: Gamma transport
Topic: Gamma detectors and flux to dose
Replies: 37
Views: 4862

Gamma detectors and flux to dose

I'm a little confused about detectors, perhaps someone can help. From here: http://ttuki.vtt.fi/serpent/viewtopic.php?f=26&t=2212&p=5884&hilit=dose&sid=4b02ee7f7418d818dd9af9e7a191f4f3#p5884 I infer that everything is done via reaction rate multipliers (MT-201-248). So I can see one could get absorb...
by Andy_Turner
Thu Mar 31, 2016 12:39 pm
Forum: Input
Topic: Restart feature in 2.1.17
Replies: 29
Views: 32103

Re: Restart feature in 2.1.17

Unfortunately, no. Oh okay. Feature request? ;) I understand Serpent2 was designed with an ethos on scalability, to run on large clusters. If there is indeed a goal to do large-scale fixed source problems (once variance reduction is implemented) then we would be talking about using 100's of cores f...
by Andy_Turner
Thu Mar 31, 2016 12:31 pm
Forum: Input
Topic: Automatic division of depletion zones
Replies: 30
Views: 41311

Re: Automatic division of depletion zones

Hi Jaakko Thanks an improved volume estimator would be very useful. The problem is that the code has no way of knowing which material zones are part of the actual geometry and which are not. The only way of identifying the zones would be to run the Monte Carlo based volume calculation routine, but a...
by Andy_Turner
Tue Mar 29, 2016 12:34 pm
Forum: Input
Topic: Restart feature in 2.1.17
Replies: 29
Views: 32103

Re: Restart feature in 2.1.17

Yes, basically you can go back to the last completed burnup step (provided that the writing of the restart file was enabled). Sorry I meant during a normal transport run, whether it is possible to continue a neutron transport calculation run that was terminated prematurely, or perhaps you want to r...