[neutron-mc] Generate a source spectra from exp. file
Emmanuel Farhi
farhi at ill.fr
Wed Aug 27 11:07:42 CEST 2003
Yes, there is a solution to use an experimental profile for the
simulation source.
First position a normal source (Source_flat or Source_gen, or ...).
Then, you may use the Filter_gen component (in the optics) to read the
contents a a file, with options="lambda, set weight". Then the first
column of the table is assumed to be the wavelength, and the second
should be the flux to set.
A rebinning/interpolation is done when loading the table. This will set
the weight of neutrons. You may also choose to multiply or add to the
existing weight.
The Filter_gen (McStas v1.7) is a replacement to the old Flux_adapter.
Just look at the MCSTASLIB/optics/Filter_gen component (or 'mcdoc
Filter_gen').
pwilk wrote:
> Thanks for the quick reply! I'll give that a go.I think you are right
> about the zero velocity neutrons.I have another quick question for
> you: Is there an easy way to simulate a source from a 2D file of
> (measured) Intensity vs. Wavelength ?Cheers,Philip
>
> -----Original Message-----
> From: farhi at ill.fr [mailto:farhi at ill.fr]
> Sent: Tuesday, August 26, 2003 3:18 PM
> To: pwilk-radiochem at hahnium.com; neutron-mc at risoe.dk
> Subject: Re: sqrt: DOMAIN error
> Hy Philip,
>
> You probably have some zero velocity neutrons or such huge
> velocities that the square gets hawfull (before getting the
> sqrt), else I can not figure out how the 'sqrt' can fail in
> the speed in L_monitor.comp.
> You may copy this component locally and change the line #76
> so that it tests the speed norm to be non zero or reasonable
> value (not huge).
>
> You may also try replacing with the Monitor_nD(options="auto
> lambda", filename="...")
>
> Cheers, Emmanuel.
>
> Philip Wilk wrote:
>
> > Hi,
> >
> > I am using the new version 1.7
> >
> > I keep getting "sqrt: DOMAIN error"
> >
> > Just like I was getting with version 1.6.4 , should I be
> > worried about this?
> > It seems to be associated with the wavelength detector
> > component.
> >
> > See example output:
> >
> > Detector: psd_begin_I=75.9887 psd_begin_ERR=0.0701353
> > psd_begin_N=3.65191e+06 "p
> > sd1.dat"
> > Detector: lambda_begin_I=75.9887
> > lambda_begin_ERR=0.0701353
> > lambda_begin_N=3.651
> > 91e+06 "erg1.dat"
> > Detector: psd_middle_I=6.2552 psd_middle_ERR=0.017862
> > psd_middle_N=1.68387e+06 "
> > psd2.dat"
> >
> > sqrt: DOMAIN error
> > Detector: lambda_middle_I=6.2552
> > lambda_middle_ERR=0.017862
> > lambda_middle_N=1.68
> > 387e+06 "erg2.dat"
> > Detector: psd_middle2_I=1.20321 psd_middle2_ERR=0.00418768
> >
> > psd_middle2_N=1.08584
> > e+06 "psd3.dat"
> > Detector: lambda_middle2_I=1.20321
> > lambda_middle2_ERR=0.00418768
> > lambda_middle2_
> > N=1.08584e+06 "erg3.dat"
> > Detector: psd_end_I=0.65266 psd_end_ERR=0.002805
> > psd_end_N=389221 "psd4.dat"
> > Detector: lambda_end_I=0.65266 lambda_end_ERR=0.002805
> > lambda_end_N=389221
> > "erg4
> > .dat"
> >
> > Cheers,
> > Philip
>
> --
> What's up Doc ?
> --------------------------------------------
> Emmanuel FARHI, http://www.ill.fr/tas/people/Farhi.html \|/ ____ \|/
> CS-Group ILL4/156, Institut Laue-Langevin (ILL) Grenoble ~@-/ oO \-@~
> 6 rue J. Horowitz, BP 156, 38042 Grenoble Cedex 9,France /_( \__/ )_\
> Work :Tel (33/0) 4 76 20 71 35. Fax (33/0) 4 76 20 76 48 \__U_/
>
>
>
--
What's up Doc ?
--------------------------------------------
Emmanuel FARHI, http://www.ill.fr/tas/people/Farhi.html \|/ ____ \|/
CS-Group ILL4/156, Institut Laue-Langevin (ILL) Grenoble ~@-/ oO \-@~
6 rue J. Horowitz, BP 156, 38042 Grenoble Cedex 9,France /_( \__/ )_\
Work :Tel (33/0) 4 76 20 71 35. Fax (33/0) 4 76 20 76 48 \__U_/
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