Problem 588

Summary:	Multiple Secondary Event Generation
Product:	Geant4	Reporter:	bongardo
Component:	processes/hadronic/processes	Assignee:	Hans-Peter.Wellisch
Status:	RESOLVED WONTFIX
Severity:	normal
Priority:	P2
Version:	6.0
Hardware:	PC
OS:	Linux

Description bongardo 2004-02-20 01:48:37 CET

I'm using the QGSP_BIC physics list. Having as particle gun a proton
(coming from the vacuum and hitting an Al shell):

0 15.3908 43.8998 6.70294 4223.15 0 Vacuum
1 14.3402 43.1064 7.22491 4223.15 3.78176e-26 Vacuum
2 3.59257 35.0717 12.6665 2734.96 5.57463 alSpCraft_phys

I got these secondary events:

3.59257 35.0717 12.6665 238.553 neutron
3.59257 35.0717 12.6665 232.845 pi+
3.59257 35.0717 12.6665 1.56615 neutron
3.59257 35.0717 12.6665 3.3586 pi+
3.59257 35.0717 12.6665 12.9521 neutron
3.59257 35.0717 12.6665 0.001 neutron
3.59257 35.0717 12.6665 0.001 neutron
3.59257 35.0717 12.6665 104.663 proton
3.59257 35.0717 12.6665 107.63 neutron
3.59257 35.0717 12.6665 5.14334 neutron
3.59257 35.0717 12.6665 103.548 proton
3.59257 35.0717 12.6665 61.7006 neutron
3.59257 35.0717 12.6665 62.6394 deuteron
3.59257 35.0717 12.6665 7.02981 deuteron

Is this meaningful? What can I argue about that Al particle that the
proton hit?

As another example (I only have a secondary event in this case, without
a proton as primary!):

2.37069 37.4603 3.13945 1.27458 neutron
2.37069 37.4603 3.13945 2.79678 gamma
2.37069 37.4603 3.13945 0.84398 gamma
2.37069 37.4603 3.13945 0.22307 Al27[0.0]
2.37069 37.4603 3.13945 2e-05 gamma

Once again, is this meaningful?

Thanks, Chris

Comment 1 bongardo 2004-03-01 03:21:59 CET

Using the Bertini cascade the bug is still present, but a little bit less
visible (in the sense that it seems, at a first sight, that it occurs rarely).

The most important thing I'd like to stress is that this strange secondary event
generation forms from the ProtonInelastic process.
I changed to major severity because I think the bug it's rather important and,
now that I got it, simpler to find and fix it (at least I hope so).

I'm using the Geant4.6.0 + patch 01 version, with the CLHEP 1.8.2.0 library.

Thanks, Chris

Comment 2 Hans-Peter.Wellisch 2004-04-20 07:10:59 CEST

Hi Chris,

  as it turns out, this is a regular feature of the parametrized models. With
the new revision of the _BIC physics lists, this should no longer occure (higher
energy limit for the theoretical model) in your case.

Many greetings,

Hans-Peter.