## Hexagonal detectors

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nico
Posts: 21
Joined: Wed Feb 28, 2018 1:57 pm
Security question 1: No
Security question 2: 93

### Hexagonal detectors

Dear Serpent team,
I suspect that there is something wrong in the way Serpent associates the tallies to the assembly numbers.

Checking the results of the attached results, you can see that the first assembly with non-zero power in the "_core0.m" file is the 243, while the first non-zero power in the "_det0.m" file is the number 210.
Counting the assemblies starting from the top-left corner of the lattice matrix and going down by rows I am okay with the "_core0.m" numeration, that seems correct.
As regards the "_det0.m" output, instead, I think that Serpent actually skips one row in the matrix...This is confirmed also if you look at output posted under the post "exagonal mesh detector (dh)" (viewtopic.php?f=15&t=3143&p=9582&hilit= ... ctor#p9582).
In this case, the non-zero flux is at position 13, but that is true only if you skip the first void row!

Hope that you could help me to understand why the two output numeration is not consistent
thank you so much
Nicolo'
Attachments
dethex_results.zip

Ana Jambrina
Posts: 619
Joined: Tue May 26, 2020 5:32 pm
Security question 1: No
Security question 2: 7

### Re: Hexagonal detectors

Fixed in Serpent 2.1.32: idx 243 corresponds with element (19,8,1).

In Serpent 2.1.31, in routine meshindex.c substitute lines 281-282 from:

Code: Select all

``````      i = i + (long)(((double)n0 - 1.0)/2.0);
j = j + (long)(((double)n1 - 1.0)/2.0);
``````
to:

Code: Select all

``````      i = i + (long)((double)n0/2.0);
j = j + (long)((double)n1/2.0);
``````
- Ana