From: Vasilis Vlachoudis (Vasilis.Vlachoudis@cern.ch)
Date: Tue Mar 06 2007 - 10:09:45 CET
Hi Alfred,
the numbers mean nothing to me!
USRTRACK and USRCOLL both score particle fluence using two different
methods one with the track length estimation and the other by
collisions. Please give a look to the related tutorial on the fluka web
site http://www.fluka.org/course/WebCourse/scoring/P007.html
Check also the USRYIELD card for scoring particle yields out of an
interaction or a region
Regards
Vasilis
-----Original Message-----
From: Tang, Alfred [mailto:atang@phys.ksu.edu]
Sent: Monday, 05 March 2007 17:16
To: Vasilis Vlachoudis; fluka-discuss@fluka.org
Subject: RE: Question about neutron balance
Dear Vasilis,
Thank you for your comments. They are very informative. I have used
source.f to input muons from a realistic profile and to score the
secondary particles using USRTRACK and USRCOLL. Below is a partial list
of the numbers that I got in unit of p/cmq/pr and cm/pr (I used the
default area=1cm^2 and volume=1cm^3):
USRTRACK
muon 1184.364
particle 8 20.14018
particle 222 6418.346
USRCOLL
muon 1161.683
particle 8 20.13256
particle 222 1180.406
Do these numbers look right? What is the main difference between
USRTRACK and USRCOLL? I am primarily interested in the production rates
of secondary particles. Can I get that information from the above
numbers? Thanks again.
Regards,
Alfred
*****************************************************
Alfred Tang
Physics Department
Kansas State University
13 Cardwell Hall
Manhattan, KS 66506
(785) 532-1699
http://www.phys.ksu.edu/personal/atang
-----Original Message-----
From: owner-fluka-discuss@fisica.unimi.it on behalf of Vasilis
Vlachoudis
Sent: Sun 3/4/2007 11:56 AM
To: Tang, Alfred; fluka-discuss@fluka.org
Subject: RE: Question about neutron balance
Hi Alfred,
The neutron balance according to your definition is related to B. Is the
term that enters in the diffusion equation for a steady in time
solution.
The diffusion equation is described as:
d(Flux(r))/dt = D*\Delta2(Flux(r)) + S(r) - \Sigma_abs*Flux(r)
where S(r) term describing the sources and \Sigma_abs the absorption
cross section:
or with words the diffusion equation is (per unit volume):
dFlux(r)/dt = -[outflow rate] + [production rate] - [absorption rate]
and for a steady state solution
[outflow rate] = [production rate] - [absorption rate] = neutron balance
While the particle 8=neutron is scoring the neutron fluence. The datum
most frequently used for describing neutron fields. The fluence defined
as the number of particles that penetrate a sphere with a cross section
of pi*r^2 = 1cm2 per unit of time and/or energy. Otherwise, the
particles crossing a surface of 1cm2 that is ALWAYS perpendicular to the
direction of the particle.
Regards
Vasilis
-----Original Message-----
From: owner-fluka-discuss@fisica.unimi.it
[mailto:owner-fluka-discuss@fisica.unimi.it] On Behalf Of Tang, Alfred
Sent: Friday, March 02, 2007 17:08
To: fluka-discuss@fluka.org
Subject: Question about neutron balance
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Dear FLUKA experts,
Suppose that A=3D(number of neutrons created)+(number of neutrons
absorbed) and B=3D(number of neutrons created)-(number of neutrons
absorbed). Is it true that neutron balance (particle number 222)
neut-bala is related to A and neutron (particle number 8) is related to
B?
Regards,
Alfred
=20
**********************************************
Alfred Tang
Department of Physics
Kansas State University
13 Cardwell Hall
Manhattan, KS 66506
(785) 532-1699
http://www.phys.ksu.edu/personal/atang
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<P><FONT SIZE=3D2 FACE=3D"Arial">Dear FLUKA experts,</FONT>
<BR><FONT SIZE=3D2 FACE=3D"Arial">Suppose that A=3D(number of neutrons =
created)+(number of neutrons absorbed) and B=3D(number of neutrons =
created)-(number of neutrons absorbed). Is it true that neutron =
balance (particle number 222) neut-bala is related to A and neutron =
(particle number 8) is related to B?</FONT></P>
<P><FONT SIZE=3D2 FACE=3D"Arial">Regards,</FONT>
<BR><FONT SIZE=3D2 FACE=3D"Arial">Alfred</FONT>
<BR><FONT SIZE=3D2 FACE=3D"Arial"> </FONT>
</P>
<P><FONT SIZE=3D2 =
FACE=3D"Arial">**********************************************</FONT>
<BR><FONT SIZE=3D2 FACE=3D"Arial">Alfred Tang</FONT>
<BR><FONT SIZE=3D2 FACE=3D"Arial">Department of Physics</FONT>
<BR><FONT SIZE=3D2 FACE=3D"Arial">Kansas State University</FONT>
<BR><FONT SIZE=3D2 FACE=3D"Arial">13 Cardwell Hall</FONT>
<BR><FONT SIZE=3D2 FACE=3D"Arial">Manhattan, KS 66506</FONT>
</P>
<P><FONT SIZE=3D2 FACE=3D"Arial">(785) 532-1699</FONT>
</P>
<P><A HREF=3D"http://www.phys.ksu.edu/personal/atang"><U><FONT =
COLOR=3D"#0000FF" SIZE=3D2 =
FACE=3D"Arial">http://www.phys.ksu.edu/personal/atang></U></A>
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