RE: Scoring Low-Energy Electrons

From: Joachim Vollaire <joachim.vollaire_at_cern.ch>
Date: Mon, 27 Jul 2009 06:48:36 +0200

Hi Johannes

A few things which may help you get started, first I did run your
program both from FLAIR or from the command and in both cases it seems
to work, however it takes a long time to complete one particle history
due to the MULSOPT parameters you are using I suspect. Instead I have
tried the following to obtain a more reasonable computing time (it is
taken from the manual), I would try this and see what results you get :

 * Maximum accuracy requested for the electron step size used in the
boundary
 * approach and in the optimisation algorithm. Single scattering activated
for
 * electrons at boundary crossing and when the step is too short for Moliere
 * (but not when the energy is too low for Moliere). Boundaries will be
 * crossed with 2 single scatterings.
 =
*...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+...
MULSOPT 1.0 1.0 1.0 1.0 0.0 2. GLOBEMF

You should also notice that FLUKA transports e-/+ and gamma down to 1
keV (not below). To set the transport value to that minimum be sure to
used the EMFCUT card. Also I would suggest you use the DEFAULTS card
which may allow you to have "customized" defaults for your problem....

Let me know if it helps resolve your problem.

Joachim

________________________________

From: owner-fluka-discuss_at_mi.infn.it on behalf of =
J.Stiller_at_stud.uni-heidelberg.de
Sent: Fri 7/24/2009 7:08 PM
To: fluka-discuss_at_mi.infn.it
Subject: Scoring Low-Energy Electrons

Dear Fluka experts,
I would like to be able to detect electrons at energies below 1keV in=20
Argon, using the USRTRACk (linear binning, starting at E_min=3D 0.0) =
card.
In the manual it is said that in order to obtain good results with low=20
energy electrons one has to use the MULSOPT card, activating only=20
single scattering. Now, I am using Flair and somehow it is not=20
possible to set WHAT(3)=3D0.0 ("Stretching") of MULSOPT... If I do not=20
take any of the values of the drag down Fluka crashes.

What am I doing wrong?

Thank you for your help and for the advice I generally received so far!

Johannes

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<HTML dir=3Dltr><HEAD><TITLE>Scoring Low-Energy Electrons</TITLE>=0A=
<META http-equiv=3DContent-Type content=3D"text/html; charset=3Dunicode">=0A=
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<DIV id=3DidOWAReplyText55342 dir=3Dltr>=0A=
<DIV dir=3Dltr><FONT face=3DArial color=3D#000000 size=3D2>Hi =
Johannes<BR><BR>A few things which may help you get started, first I did =
run your program both from FLAIR or from the command and in both cases =
it seems to work, however it takes a long time to complete one particle =
history due to the MULSOPT parameters you are using I suspect. Instead I =
have tried the following to obtain a more reasonable computing time (it =
is taken from the manual), I would try this and see what results you get =
:<BR><BR>&nbsp;* Maximum accuracy requested for the electron step size =
used in the boundary<BR>&nbsp;* approach and in the optimisation =
algorithm. Single scattering activated for<BR>&nbsp;* electrons at =
boundary crossing and when the step is too short for Moliere<BR>&nbsp;* =
(but not when the energy is too low for Moliere). Boundaries will =
be<BR>&nbsp;* crossed with 2 single =
scatterings.<BR>&nbsp;*...+....1....+....2....+....3....+....4....+....5.=
...+....6....+....7....+...<BR>&nbsp;MULSOPT&nbsp;&nbsp;&nbsp;&nbsp;&nbsp=
;&nbsp;&nbsp;&nbsp;&nbsp; 1.0&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; =
1.0&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; =
1.0&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; =
1.0&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; =
0.0&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 2. GLOBEMF<BR><BR>You should =
also notice that FLUKA transports e-/+ and gamma down to 1 keV (not =
below). To set the transport value to that minimum be sure to used the =
EMFCUT card. Also I would suggest you use the DEFAULTS card which may =
allow you to have "customized" defaults for your problem....<BR><BR>Let =
me know if it helps resolve your =
problem.<BR><BR>Joachim<BR><BR></FONT></DIV></DIV>=0A=
<DIV dir=3Dltr><BR>=0A=
<HR tabIndex=3D-1>=0A=
<FONT face=3DTahoma size=3D2><B>From:</B> owner-fluka-discuss_at_mi.infn.it =
on behalf of J.Stiller_at_stud.uni-heidelberg.de<BR><B>Sent:</B> Fri =
7/24/2009 7:08 PM<BR><B>To:</B> =
fluka-discuss_at_mi.infn.it<BR><B>Subject:</B> Scoring Low-Energy =
Electrons<BR></FONT><BR></DIV>=0A=
<DIV>=0A=
<P><FONT size=3D2>Dear Fluka experts,<BR>I would like to be able to =
detect electrons at energies below 1keV in&nbsp;<BR>Argon, using the =
USRTRACk (linear binning, starting at E_min=3D 0.0) card.<BR>In the =
manual it is said that in order to obtain good results with =
low&nbsp;<BR>energy electrons one has to use the MULSOPT card, =
activating only&nbsp;<BR>single scattering. Now, I am using Flair and =
somehow it is not&nbsp;<BR>possible to set WHAT(3)=3D0.0 ("Stretching") =
of MULSOPT... If I do not&nbsp;<BR>take any of the values of the drag =
down Fluka crashes.<BR><BR>What am I doing wrong?<BR><BR>Thank you for =
your help and for the advice I generally received so =
far!<BR><BR>Johannes<BR></FONT></P></DIV></BODY></HTML>
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Received on Mon Jul 27 2009 - 10:05:57 CEST

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