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Forum: Event and Track Management
Re: Question results very sensitive to step size (Cristian Bungau)
Date: 13 Nov, 2010
From: michel maire <michel maire>

On Fri, 12 Nov 2010 19:31:45 GMT, Cristian Bungau wrote:
> Dear all,
> 
> I am simulating the interactions of 800 MeV protons with a thin (10 mm)
> graphite target. I am interested in the (very) rare events when positive
> pions decay at rest inside the target. I was advised to run these
> simulations with reduced step size to ensure that the Delta E is small
> as it could be that the cross section is not adjusted for the end-point
> energy value.
> 
> However it turns out that the smaller I force the step size to be, the
> more positive pions decays at rest I get, as there are more and more
> proton interactions inside the target. I already went down to 100
> micrometers step size limit. So my question is: is there an optimum
> value for the step size being given the proton energy of 800 MeV and the
> target thickness of 10 mm, or should I be running the simulations with
> no step limitations?
> 
> Thank you very much,
> 
> Best regards,
> 
> Cristian
> 

 Inelastic interaction of proton must be independant of step size !
 In your situation, it must be enough to run without step limitation. 
 It is hard to believe your result.

 As Vladimir asked, how do you count inelastic interaction ? and how do you control step size ? Is there something special in your physics list ?

    Cheers,  Michel

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1 Feedback: Re: results very sensitive to step size   (Cristian Bungau - 13 Nov, 2010)
1 None: Re: results very sensitive to step size   (michel maire - 15 Nov, 2010)
2 None: Re: results very sensitive to step size   (michel maire - 16 Nov, 2010)
1 Feedback: Re: results very sensitive to step size   (Cristian Bungau - 16 Nov, 2010)
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3 Feedback: Re: results very sensitive to step size   (Gumplinger Peter - 16 Nov, 2010)
1 More: Re: results very sensitive to step size   (Cristian Bungau - 16 Nov, 2010)
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