From: Vasilis Vlachoudis (Vasilis.Vlachoudis@cern.ch)
Date: Sun Mar 04 2007 - 18:56:12 CET
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 =
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