|Message: Cross-section Biasing Weights||Not Logged In (login)|
Click on the Forum title, e.g. on the "Forums by Category" page, to read a sequence of postings to the Forum and its threads all in one page. If you are only interested in one thread or the thread following a specific posting, click the thread or the posting, which takes you to a smaller page, which contains only the part you are interested in and may be easier to navigate.
Messages are "chained" if there are only replies at the first level, i.e. 1/1.html, 1/1/1.html etc. In case of "chained" messages the message number is replaced by the icon and there is no indentation.
Inline: Display the subject line only or also the text of the posting(s); for the choice "All" the "Outline" choices are switched off.
|1||0||1||no text / full text of posting|
|2||1||All||text for level 1 only / text for All postings|
Outline: Choose the depth of the posting thread, successive toggle controls provide increasing detail.
|1||2||1||2 levels / 1 level (original posting)|
|2||3||2||3 levels / 2 levels|
|3||3||All||3 levels / all levels (all postings)|
I'm interested in cross-section biasing and have been testing it out with the example GB01. I've modified the code slightly; just to record some hit information in the target. The only biasing I'm applying is a 2x scaling of the cross-section, and only for neutrons.
When I look at the particle weights (recorded for each particle step in the target), there is a distribution of weights that includes values > 1.
This is surprising to me; I thought the weight would be set by (unweighted process cross-section)/(weighted process cross-section). If that's true then there should be events that are weighted by 0.5 (neutron interactions), and events that are weighted by 1 (non-neutron interactions), and any multiple of 0.5 (for successive neutron interactions). So why are there weights > 1?
|Inline Depth:||Outline Depth:||Add message:|