Re: Fluka2011.2.16 released

Dear Alfredo,

Thanks for your valuable comment and necessary steps on the problem that I
am facing. The combination of gas pressure and density in my problem is
probably wrong. I am still working on that. However, recently I rebuilt the
input file for the same geometry and the problem seems to be disappeared.
The program did not crush so far.

I appreciate the inputs from fluka experts and users and this is helping me
out in learning fluka.

Sincerely
Mohammad,
Dept of Physics, Oklahoma State University
USA

On Sat, Oct 27, 2012 at 7:51 AM, Alfredo Ferrari <alfredo.ferrari_at_cern.ch>wrote:

> Dear Fluka users
>
> a respin, fluka2011.2.16, has been just released. This respin fixes
> the following conditions:
>
> a) a slight discontinuity around particle energies corresponding to
> the threshold for delta production (eg around 50 MeV protons for
> a delta threshold of 100 keV)
> b) a crash when using PPSOUR for hadron-nucleus in the energy range
> of PEANUT
> c) nonsense results and crashes when using gases with possibly
> incorrect pressure/density. In some conditions, like those experienced
> by Mohammad Islam in his message "Fluka crashes for higher primaries
> for heavy ion", the user could define a combination of
> density/pressure
> for a gas which makes it out of the validity range
> of the Sternheimer-Peierls general formula for the density effect for
> gases. Very likely or the density (2.27E-4) or the pressure (1/50 atm)
> is wrong in Mohammad input (Mohammad please let us know if this
> supposition is true). Anyway a gas with that composition/density
> /pressure is unmanageable from the point of view of the standard
> Sterhneimer-Peierls treatment of the density effect in stopping power.
> The conseuquences are potentially catastrophic with computed stopping
> powers which can be ten orders of magnitude or more larger than real
> ones. Now a protection is built-in stopping the code at initialization
> time if a similar condition is detected. If such a gas do really
> exist,
> the user can still run Fluka by providing manually sensible density
> effect parameters by means of the STERNHEI input card: of course the
> user takes full responsibility for the physical soundness of
> such parameters
> d) the incorrect use of HEAVYION beams which are actually
> defined through the HI-PROPE card to be a p,n,d,3-H,3-He or 4-He
> is now prevented. In such a case now the code stops. Please use
> PROTON, NEUTRON, DEUTERON etc beams if you need one of these
> instead of "cheating" the code.
> e) the "smearing" of the energy at which Fluka switches from the
> the internal models to Dpmjet for h-p and h-A collisions is now
> activated by default: it was off by mistake. The transition occurs
> gradually between 10 and 30 TeV lab energy
>
> At minimum a) is changing the random number sequence (and very slightly
> the results) hence all users are kindly invited to upgrade to the current
> respin. Assistance/bug correction will be provided only for the
> latest respin.
>
> The FLUKA developer team
>
> +----------------------------------------------------------------------+
> | Alfredo Ferrari || Tel.: +41.22.76.76119 |
> | CERN-EN/STI || Fax.: +41.22.76.69474 |
> | 1211 Geneva 23 || e-mail: Alfredo.Ferrari_at_cern.ch |
> | Switzerland || |
> +----------------------------------------------------------------------+
>
>
>
Received on Thu Nov 01 2012 - 16:23:41 CET