Re: FLUKA: USRBDX results and running speed

[Stefan Roesler <sroesler@SLAC.Stanford.EDU>]

Fan,

I just had a quick look into your input. Your beam momentum is 1GeV/c;
therefore the maximum kinetic energy a neutron can have is only about
0.43GeV. In contrast to what you wrote you have defined the inner shell
(region 3) to be Aluminum and the outer Tungsten (region 4). Furthermore I
suggest that you use a lower energy limit for the usrbdx-binning which
coincides with one of the low-energy neutron group boundaries (see
manual).

and Alberto,

> b) Card STEPSIZE: this is rarely needed, unless you work with a magnetic
 ...
> c) Card GEOBEGIN with WHAT(2) = 0.01: the manual says clearly that
>    this option is "used to set the accuracy parameter - reserved for
>    program development". You should not touch it unless you know well
 ...
> This is because you have commented off the RANDOMIZE card. In this
 ...
> - Option OUTLEVEL is obsolete and has no practical effect. I am planning
 ...
>   cannot guess). Also WHAT(5) is set = 1., which is likely to produce
>   tons of output (2 lines per event, times 100000 events requested...)

All these options are used in mu.inp which is the one and only example for
an input which is provided with the FLUKA-package. If these options are
not recommended or only tto be used for program development etc. I would
suggest if the input-example does not make use of them (how should the
user know...). Also, it would be better if RANDOMIZE was not commented in
the input-example file as this is extremely misleading!

Stefan

___________________________________

Stefan Roesler
SLAC
P.O. Box 4349, MS 48
Stanford, CA  94309

Tel:    650-926-2048
Fax:    650-926-3569
E-mail: sroesler@slac.stanford.edu
        Stefan.Roesler@cern.ch