GSI Forum: Simulation Issues » Particle reached max step number

Home » R3BRoot » Simulation Issues » Particle reached max step number

Show: Today's Messages :: Polls :: Message Navigator

Particle reached max step number [message #19444]

Thu, 18 August 2016 10:37

Oleg
Messages: 19
Registered: August 2016
Location: GSI

occasional visitor

From: *gsi.de

Hello,

the alpha particle in the gas produce many electrons but not so many as it should be.
The error is:
*** Particle reached max step number (15000). ***
Where one can set the maximum step number, let say 30000?
And eventually - increase the step size?

Oleg.

Report message to a moderator

Re: Particle reached max step number [message #19445 is a reply to message #19444]

Thu, 18 August 2016 10:53

Dmytro Kresan
Messages: 166
Registered: June 2004

first-grade participant

From: *gsi.de

In your case with actar simulations, you need to adjust two files in gconfig directory: g4GarfieldConfig.C and g4garfieldconfig.in

In first you can set maximum number of steps.
You can set only maximum step length. The minimum step size is controlled by energy cut for a specific particle / process, larger cut --> larger step size. Refer to Geant4 manual.

I saw also that you need to change garfield region in g4garfieldconfig.in to helium.

Best regards,
Dima

Report message to a moderator

Re: Particle reached max step number [message #19446 is a reply to message #19445]

Thu, 18 August 2016 11:07

Oleg
Messages: 19
Registered: August 2016
Location: GSI

occasional visitor

From: *gsi.de

In g3GarfieldConfig.C:

//set geant4 specific stuff
geant4->SetMaxNStep(30000); // default is 30000

In g4garfieldconfig.in:

# Garfield simulation configuration
/mcPhysics/fastSimulation/setModel garfieldModel
/mcPhysics/fastSimulation/setParticles gamma e- alpha
/mcPhysics/fastSimulation/setRegions helium

This all does not help.
The step limit 15000 is set somewhere else.

Oleg.

Report message to a moderator

Re: Particle reached max step number [message #19447 is a reply to message #19446]

Thu, 18 August 2016 11:17

Dmytro Kresan
Messages: 166
Registered: June 2004

first-grade participant

From: *gsi.de

Yes, you are right. Another try.

15000 limit is set in the file macros/r3b/actar/r3ball.C :

Int_t nSteps = -15000;
gMC->SetMaxNStep(nSteps);

In addition, concerning step size. In the same directory the file g4config2.in (currently) :

/run/setCut 1. mm
/run/setCutForRegion ArCO2 1. um

Best regards,
Dima

Report message to a moderator

Re: Particle reached max step number [message #19448 is a reply to message #19447]

Thu, 18 August 2016 11:25

Oleg
Messages: 19
Registered: August 2016
Location: GSI

occasional visitor

From: *gsi.de

In macros/r3b/actar/r3ball.C
there are few lines:

// ------ Increase nb of step for CALO
Int_t nSteps = -15000;
gMC->SetMaxNStep(nSteps);

I was sure it is related to the calorimeter and not our detector. Is it?

In macros/r3b/actar/g4config2.in:

/run/setCut 1. mm
/run/setCutForRegion helium 100. um

Regards, Oleg.

Report message to a moderator

Re: Particle reached max step number [message #19449 is a reply to message #19448]

Thu, 18 August 2016 11:36

Dmytro Kresan
Messages: 166
Registered: June 2004

first-grade participant

From: *gsi.de

I do not know who has put this comment there, but it is meaningless. The limit is set globally.

The cuts you have to adjust by testing.

Best regards,
Dima

Report message to a moderator

Previous Topic:	SimpleAtomPhotoAbsCS
Next Topic:	Geant3 crash on ions

Goto Forum:

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Sat Jul 12 02:56:38 CEST 2025

Total time taken to generate the page: 0.00778 seconds