Re: Inconclusive results with USIMBS

Hi David

Please see the Notes of the latest respin that refer to your question.

Cheers
Stefan

On Tue, 27 Dec 2011, davhorv112_at_gmail.com wrote:

> Dear Fluka Developers,
>
> I recently started a Fluka - MCNP comparison / result check for my
> project. And during this I noticed that the results from Fluka are
> inconclusive if I use USIMBS. So I started to run some test to check
> it.
>
> It these tests I scored the Flux (Total Response) in BurkK region with USRTRACK.
>
> In the first three test (v1, v2, v3) I didn't use the USIMBS, only
> three different region importance biasing setup with BIASING cards.
> This three run gave the same result 3,52E-8 1/cm2/primary, and the
> differences between them was in the errors range.
> v1: 3.5119321E-08 +/- 1.049784%
> v2: 3.5208146E-08 +/- 0.2559452%
> v3: 3.5244092E-08 +/- 0.5248427%
>
> For the test from v4 to v9 I used different USIMBS codes. For v4, v5,
> v6 I tried to make the similar biasing like in the first tree test,
> but the results got inconclusive.
> The results were:
> v4: 2.3961730E-08 +/- 0.5406314%
> v5: 3.9323904E-08 +/- 0.5327918%
> v6: 6.5616213E-08 +/- 1.557709%
>
> For v7, v8, v9 I used an empty USIMBS.f with a fix FIMP value.
> v7: FIMP = 1
> v8: FIMP = 1.05
> v9: FIMP = 1.2
>
> For v7 I got back the result with no USIMBS, but the other two was off again:
> v7: 3.5149231E-08 +/- 0.7727996%
> v8: 3.9468961E-08 +/- 0.8326670%
> v9: 5.2824475E-08 +/- 0.5843777%
>
> For me it looks that the particle weight calculation can be wrong when
> USIMBS is used. Please check what could be the problem.
>
> 2011.2.8 version of Fluka was used for the test.
>
> The used input and usimbs.f files and the quoted result files can be
> downloaded from http://users.hszk.bme.hu/~hd556/usimbs.tar.gz
>
> Best regards,
> David HORVATH
>
>
Received on Mon Jan 23 2012 - 00:10:43 CET