Re: [fluka-discuss]: physics settings for cosmogenic neutron production/capture

From: Alfredo Ferrari <alfredo.ferrari_at_cern.ch>
Date: Mon, 28 Apr 2014 23:04:36 +0200

Activate PEANUT. The only reason for the old generator being still the
default (btw it will no longer be in the next release) is that it is much
faster and for many problems results are almost the same (the
hadron-nucleon physics being the same, the energetic particles produced or
almost identical). Where the two generators differ is really in the
nuclear part, cascading/evaporation etc so for residual predictions the
old model is really discouraged.

CHARMDECay does not make any difference for you, it just changes from on
the spot decay to transport and decay for charmed particles, relevant only
if one is looking for vertex reconstruction or similar

                  Ciao
                 Alfredo


+----------------------------------------------------------------------+
| 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 || |
+----------------------------------------------------------------------+

On Mon, 28 Apr 2014, Joshua Albert wrote:

> Dear FLUKA experts,
>
> I have been updating my simulation for cosmogenic neutron production and capture (residual nuclei are important) on our detector to have the appropriate thresholds and physics settings. Aside from the PRECISIOn defaults, I have now added the following:
>
> heavy ion transport
> EM dissociation
> mu-mu pair production
> photonuclear interactions at all energies
> coalescence and evaporation
> an EMF cut of 1 MeV for e+-, and 330 keV for gammas.
>
> Of the remaining settings that might be changed, the main ones I am not sure about are activating PEANUT for higher energies, and CHARMDECay. For PEANUT, it isn't clear to me whether this is not the default because the old generator is still better, if it is just momentum keeping it from being the default. In any case, would either of these processes be a good idea to activate? I'd rather not slow down the simulation for nothing, but I'm not clear on how these would affect cosmogenic spallation and other neutron-producing processes.
>
> Thanks!
> Josh
>
> The relevant part of the input file is:
> USERWEIG 0.0 1.
> IONTRANS HEAVYION
> PHYSICS 2. EM-DISSO
> PHOTONUC 1111. MUMUPAIR
> PHOTONUC 1. Xenon Xenon
> MUPHOTON 1. HYDROGEN CHROMIUM
> PAIRBREM 3. 0.0 0.0003 HYDROGEN CHROMIUM
> PHYSICS 1. COALESCE
> PHYSICS 3. EVAPORAT
>
>
Received on Tue Apr 29 2014 - 00:22:14 CEST