# Geometry problems

From: <francesca.belloni_at_ts.infn.it>
Date: Fri, 17 Apr 2009 10:57:49 +0200 (CEST)

Dear FLUKA users.
I'm trying to score energy deposition as a function of the angle
between the z-axis and the direction of the generated particle. In order
to define different angular regions around the z axis,truncated cylinders
(TRC) were drawn.
These TRC, in my intentions, should have the same height parallel to
the z-axis, the same coordinates of the centre of the major circular base
(and hence the same vertice), but different major radii.
As a first step, in order to debug my geometry I begun with
"macroscopic" bodies (for example, the target thickness was set equal to 1
cm instead than equal to 4.2689E-5) and just 2 cones. My input file
(235U_old.inp) gave a geometry error, which I can't see.

**** Geometry debugging requested and activated ****
from X= 0.000000000E+00 to X= 1.000000000E+01 in step dX= 1.000000000E-01
from Y= 0.000000000E+00 to Y= 1.000000000E+01 in step dY= 1.000000000E-01
from Z= 0.000000000E+00 to Z= 1.000000000E+01 in step dZ= 1.000000000E-01

**** Lookdb: Geometry error found ****
**** The point: 1.1 1.1 1.1 ****
**** is contained in more than 1 region ****
**** (regions: 5 Reg.#5 7 Reg.#7 ) ****

**** Lookdb: Geometry error found ****
**** The point: 1.4 1.4 1.4 ****
**** is contained in more than 1 region ****
**** (regions: 5 Reg.#5 7 Reg.#7 ) ****

**** Lookdb: Geometry error found ****
**** The point: 1.7 1.7 1.7 ****
**** is contained in more than 1 region ****
**** (regions: 5 Reg.#5 7 Reg.#7 ) ****

**** Lookdb: Geometry error found ****
**** The point: 2. 2. 2. ****
**** is contained in more than 1 region ****
**** (regions: 5 Reg.#5 7 Reg.#7 ) ****

I modified the geometry in 2 different ways:
1. setting the minor radii to a number different from 0 (235U_radii.inp)
2. subtracting every time all inner cones (thought I thought it was not
necessary) (235U_subtracting.inp)

In both cases the debugging gives no mistake anymore.
Could someone tell me what was wrong in my first input file, please?

As a second step, I came back to the real sizes and scored energy
deposition in the whole gas around the target (235U.inp), with no
attention to angles. Then I scored energy deposition in the whole gas
again, but dividing the gas in 2 regions according to angles
(235U_mic_trc.inp). I expected that the sum of 2 histograms of energy
deposition (in region #4 and #5 of the 235U_mic_trc.inp) had to be equal
to the energy deposited in region #4 of the file 235U.inp. But I obtain
something different ("Results.ps").
Thinking this could be due to some energy cut, I changed 235U_mic_trc.inp
into 235U_mic_trc_OR.inp. In this file the region #4 and #5 of
235U_mic_trc.inp are unified in one region using "OR".
The histogram of the deposited energy in region #4 of 235U.inp and of
235U_mic_trc_OR.inp are exactly the same now. Is the difference (in the
deposited energy) between the results given by 235U.inp and
235U_mic_trc.inp really given by energy cuts, or do I make a geometry

Thanks.
Best regards,
Francesca Belloni

P.S.
As for my previous message, thanks for help!
As for sampling only in forward direction,excuse me: I had to speak