Re: TCQUENCH parameters

RE: TCQUENCH parametersHello,

Yes, I have noticed that attachment didn't find it's way to the discussion,
but anyway...
The trick is that I don't see protons with particular TCQUENCH parameters...
with USRBIN without time cut-off I perfectly see these protons... and,
increasing cut-off time by a few orders of magnitude I also can see them.
And the situation is the same for 10 MeV protons.

Anyway, I went to simplify my model even more, so it is now 10 MeV protons
in vacuum with PRECISIO defaults. For 10-MeV protons I estimate their
velocity to 4.3E+09 cm/s. Then I put two USRBIN's 0.1 cm and 100 cm away
from the beam origin position on the beam axis. I expect to "see" protons in
these beams in 2.3E-11s and 2.3E-8s respectively. In fact, I see my protons
in both these bins after exactly 1.54932E-4s which suggests that I deal not
with the beam travel time, but some other temporal parameter.

So, my questions are:
1) What is the physical meaning of the WHAT(1) parameter in the TCQUENCH?
What is the reference time from which the WHAT(1) seconds are counted?
2) If the reference is a beam particle origin time, then please help me to
find what is going wrong (or what is made wrong) in my simulation?

The input is included below. I run in the latest FLUKA2008 3b.0:

TITLE
Fluka TCQUENCH study. 1.04.2009. Andrey Smolyakov. ITEP.
*
*
DEFAULTS
PRECISIO
*23456789 123456789 123456789 123456789 123456789 123456789 123456789
123456789
*
*
BEAM 0.01 0.0 0.0 0.0 0.0 -1.0 PROTON
BEAMPOS 0.0 0.0 -0.1 0.0 0.0
*
PHYSICS 2.0
EVAPORAT
EVENTYPE 0.0 0.0 2.0 0.0 0.0 0.0 DPMJET
*
*23456789 123456789 123456789 123456789 123456789 123456789 123456789
123456789
*
*
GEOBEGIN
COMBINAT
                    Target - thick
  XYP 001 0.0
  XYP 002 3.0
*
* GENERAL BODIES
*
  SPH 003 0.0 0.0 0.0 50000.0
  SPH 004 0.0 0.0 0.0 49600.0
  SPH 005 0.0 0.0 0.0 49500.0
  END
*23456789 123456789 123456789 123456789 123456789 123456789 123456789
123456789
*
* Vacuum volumes 1
*
  VC1 5 +005
*
* Generic bodies 2,3
*
  VAC 5 +004 -005
  BHL 5 +003 -004
  END
*234 6789 123456 890123 567890 234567 901234 678901 345678 012345 789012x
GEOEND
*
*23456789 123456789 123456789 123456789 123456789 123456789 123456789
123456789
*
*
ASSIGNMA 2.0 1.0 2.0 1.0 0.0
ASSIGNMA 1.0 3.0 3.0 0.0 0.0
*
*
USRBIN 10.0 1.0 21.0 0.5 0.5 1.0 TOF_0
USRBIN -0.5 -0.5 0.0 1.0 1.0 1.0 &

*
USRBIN 10.0 1.0 22.0 0.5 0.5 101.0 TOF_1
USRBIN -0.5 -0.5 100.0 1.0 1.0 1.0 &
*
TCQUENCH 3.0E-11 0.0 0.0 1.0 1.0 0.0
TCQUENCH 3.0E-08 0.0 0.0 2.0 2.0 0.0
*23456789 123456789 123456789 123456789 123456789 123456789 123456789
123456789
*
USRBIN 10.0 1.0 98.0 0.5 0.5 101.0
ETERNAL
USRBIN -0.5 -0.5 100.0 1.0 1.0 1.0 &
*
*23456789 123456789 123456789 123456789 123456789 123456789 123456789
123456789
RANDOMIZE 1.0 5364791.0
START 1E+03
*23456789 123456789 123456789 123456789 123456789 123456789 123456789
123456789

----- Original Message -----
From: Mario Santana Leitner
To: Andrey Smolyakov ; fluka-discuss_at_fluka.org
Sent: Wednesday, April 01, 2009 11:14 AM
Subject: RE: TCQUENCH parameters

Hi Andrey,

I think that you forgot to attach the input file.

Anyway, one of the reasons why you don't see a signal may well be the energy
of your protons (~10 eV?), which is below the transport threshold for
charged hadrons (1000 eV, please see
http://www.fluka.org/fluka.php?id=man_onl&sub=3), which means that your
protons are killed as soon as they are shot and they don't reach your
detector.

Mario

-----Original Message-----
From: owner-fluka-discuss_at_mi.infn.it on behalf of Andrey Smolyakov
Sent: Tue 3/31/2009 4:29 PM
To: fluka-discuss_at_fluka.org
Subject: TCQUENCH parameters

Hello,

I'm somehow stuck with the TCQUENCH option in Fluka...
Could you please explain what is exactly the reference time from which
the WHAT(1) seconds are counted. Is it a time when primary particle
originated, or a time when the binning in question scored it's first
event? Or what?

I need to simulate a TOF detector and I started with a simple model
(attached is my input file), where non-relativistic proton beam (~10 eV)
originates in vacuum and travels towards the area (100 cm away) where I
score protons' track-lenght density with the USRBIN option. Since this
is a non-relativistic case I use classical formulas to estimate time for
my primary beam to reach the detector, but I can see nothing in the
detector with these times. Increasing scoring time 3 orders of magnitude
does help to score something, but still I'm not clear what is wrong.
Well, it may be that I miss out something very simple but in any case I
would really appreciate your help as I'm stuck with it %)

Thanks in advance,
Andrey.
Received on Wed Apr 01 2009 - 13:28:56 CEST