Re: why some regions show 0 deposited enery values in some circles, (fwd)

From: Alberto Fasso' <fasso_at_SLAC.Stanford.EDU>
Date: Wed, 29 Dec 2010 07:28:02 -0800 (PST)

I forward to the discussion list this email that I got privately in answer to my
reply. I would like to remind Danny and all the users that all correspondence
should be kept on the discussion list and not sent to private addresses.
There are several reasons for this:
1) all users can be interested in the problem proposed, and in the answers
2) some users could be able to give an answers themselves (it has happened!)
3) having sent a first answer does not necessarily imply that I am able,
     or have the time, to continue the discussion myself. In the present case,
     I will have a look at the input and output files, but I am not sure that
     I will be able to give an answer. Maybe somebody else can

Alberto Fasso`

---------- Forwarded message ----------
Date: Wed, 29 Dec 2010 00:25:50 -0800
From: ???<dengmw_at_student.sysu.edu.cn>
To: "Fasso, Alberto"<fasso_at_slac.stanford.edu>
Subject: Re: why some regions show 0 deposited enery values in some circles,

Hi,
As for the first question,you're right.As i raised the primaries number in
magnitude,values of scoring deposited energy by region no longer stick to 0,but
the variance is quite large among different circles.In this work,in my
opinion,deposited energy and dose in the water regions are basiclly derived from
photons which comes from the bremsstrahlung of electrons.And now i want to
reduce the variance by assign a splitting factor to the electrons which have
bremsstrahlung effect to give birth to photons in some designaated regions,for
example,the target and other components of the electron accelerator and the
water rigion.How could i do this with flair?I have studied the BIASING card and
the EMF-BIAS card from fluka manual,but i could't make it out.

As for the second question,i would attach my input files and outfiles to this
letter.By the way,the AUXSCORE card seems not to work for there is no direct
dose results in the corresponding USRXXX output files.

Thank you so much for your help.Wish you happy New Year.

Yours,
Danny

???: "Alberto Fasso'"<fasso_at_SLAC.Stanford.EDU>
???: "fluka-discuss"<fluka-discuss_at_fluka.org>
??: =dengmw_at_student.sysu.edu.cn
????: ???, 2010? 12 ? 28? ?? 11:55:03
??: Re: why some regions show 0 deposited enery values in some circles,

Hi Danny,

> i choose electron as particle source,and i score DEPOSTIED ENERGY and
> dose by region.i want to detect the pdd in water,so i creat 30 regions
> in the a bigger water region.i run for a few circles,but among these 30
> regions,some show 0 deposited energy values in some circles,while in
> other circles they don't show 0 deposited energy values anymore.and as i
> increase the primaries,some regions (which show 0 values in a less
> primaries run) begin to show deposited energy value which no longer
> equal to 0,but some regions still stick to show 0 value of deposited
> energy values.

All this is easily explained by the lack of statistics. There are too few
primaries in each cycle.

> what's more,all 30 regions show 0 dose results in all
> circles.what's wrong?

In this case, something is wrong (if there is energy deposition, there
must be also dose). But you haven't given us any useful information.
Please send your input and output files

Alberto

Received on Thu Dec 30 2010 - 09:36:26 CET

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