<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
<html>
Hi Ulrich,
<p>You are right, you may use groups in order to catch the neutrons that
do not follow the 'right' way, or an other solution is to use the Monitor_nD
with "parallel" word in the option string parameter (this does about the
same job as GROUP but only for monitors...).
<p>Emmanuel.
<p>"Ulrich C. Wildgruber MPI fuer Metallforschung Stuttgart" wrote:
<blockquote TYPE=CITE>"Ulrich C. Wildgruber MPI fuer Metallforschung Stuttgart"
wrote:
<br>>
<br>> Hi everybody!
<br>>
<br>> I'd like to draw your attention to an instrument file (attached)
were
<br>> we don't understand what happens for certain input parameter sets:
<br>>
<br>> parameter set 1: TTM = 80.0
<br>>
PHM = 40.0
<br>>
E = 4.131meV (4.45A)
<br>>
DWERT = 3.461(A)
<br>>
<br>> parameter set 2: TTM = 84.0
<br>>
PHM = 42.0
<br>>
E = 4.131meV
<br>>
DWERT = 3.325
<br>>
<br>> If I did Bragg's equation right we should see a reflection in both
<br>> cases. However the intensity is 0 for parameter set "2".
<br>> What are we doing wrong?
<br>>
<br>> Any advice is appreciated!
<br>>
<br>> Thanks
<br>>
<br>> Ulrich
<br>>
<br>> --
<br>> Ulrich WILDGRUBER
<br>> wildgrub@dxray.mpi-stuttgart.mpg.de
<br>> wwwmf.mpi-stuttgart.mpg.de/abteilungen/dosch/dosch.html
<br>> -----------------------------------------------------------------------------
<br>> Max-Planck-Institut für Metallforschung | Technische Universität
München
<br>> Heisenbergstr. 3
| ZWE Neue Forschungs-Neutronenquelle
<br>>
| Instrumentierung
<br>> D-70569 Stuttgart
| D-85747 Garching/München
<br>> Tel.: (+49)-711-689-1900
| Tel.: (+49)-89-289-14681
<br>> Fax.: (+49)-711-689-1902
| Fax.: (+49)-89-289-14666
<br>>
<br>> --------------------------------------------------------------------------------
<br>> DEFINE INSTRUMENT MCRY_test(TTM, PHM, E, DWERT)
<br>>
<br>> /*
test version 05/2004
*/
<br>> /*
*/
<br>>
<br>> DECLARE
<br>> %{
<br>> double dist1 = 2.5;
<br>> double dist2 = 2.5;
<br>> double beam_width = 0.05;
<br>> double beam_height = 0.05;
<br>> double mos0 = 22.6;
<br>> double ref0 = 0.7;
<br>> %}
<br>>
<br>> INITIALIZE
<br>> %{
<br>> %}
<br>>
<br>> TRACE
<br>>
<br>> COMPONENT a1 = Arm()
<br>> AT (0,0,0) ABSOLUTE
<br>>
<br>> /*
<br>> COMPONENT source = Source_div_lambda(
<br>> width
= 0.062,
<br>> height
= 0.122,
<br>> hdiv
= 1.0,
<br>> vdiv
= 1.0,
<br>> //lambda_0 = 2.0,
<br>> lambda_0 = LAMBDA,
<br>> d_lambda = 0.1)
<br>> AT (0,0,0) RELATIVE a1 ROTATED (0,0,0) RELATIVE a1
<br>> */
<br>>
<br>> COMPONENT source = Source_div(
<br>> width
= 0.062,
<br>> height
= 0.122,
<br>> hdiv
= 1.0,
<br>> vdiv
= 1.0,
<br>> E0
= E,
<br>> dE
= 0.1)
<br>> AT (0,0,0) RELATIVE a1 ROTATED (0,0,0) RELATIVE a1
<br>>
<br>> /* monitoring primary beam... */
<br>> COMPONENT sum1 = Monitor(
<br>> xmin = -0.1, xmax
= 0.1,
<br>> ymin = -0.1, ymax
= 0.1)
<br>> AT(0, 0, dist1+0.0171) RELATIVE a1 ROTATED (0,0,0) RELATIVE
a1
<br>>
<br>> COMPONENT psd1 = PSD_monitor(
<br>> xmin = -0.1, xmax
= 0.1,
<br>> ymin = -0.1, ymax
= 0.1,
<br>> nx = 41,
<br>> ny = 41,
<br>> filename = "NL1.psd")
<br>> AT(0, 0, dist1+0.0172) RELATIVE a1 ROTATED (0,0,0) RELATIVE
a1
<br>>
<br>> COMPONENT div1 = Divergence_monitor(
<br>> xmin = -0.1, xmax
= 0.1,
<br>> ymin = -0.1, ymax
= 0.1,
<br>> nh = 41,
<br>> nv = 41,
<br>> h_maxdiv = 2.0,
<br>> v_maxdiv = 2.0,
<br>> filename = "NL1.div")
<br>> AT(0, 0, dist1+0.0173) RELATIVE a1 ROTATED (0,0,0) RELATIVE
a1
<br>>
<br>> /* end of monitoring primary beam... */
<br>>
<br>> /********************************************************/
<br>> /*
Monochromator
*/
<br>> /********************************************************/
<br>> /****************************************/
<br>> /* center crystal package - position 0 */
<br>> /****************************************/
<br>>
<br>> COMPONENT mono0 = Arm()
<br>> AT (0, 0, dist1+0.167+0) RELATIVE a1 ROTATED (0, PHM,
0) RELATIVE a1
<br>>
<br>> COMPONENT m0 = Monochromator_flat(
<br>> zmin = -0.011, zmax
= +0.011,
<br>> ymin = -0.003, ymax
= +0.003,
<br>> mosaich = mos0,
<br>> mosaicv = mos0,
<br>> r0 = ref0,
<br>> DM = DWERT)
<br>> AT (0, 0, 0) RELATIVE mono0 ROTATED (0, 0, 0) RELATIVE
mono0
<br>>
<br>> /* monitoring transmitted beam... */
<br>> COMPONENT psd2 = PSD_monitor(
<br>> xmin = -beam_width,
xmax = beam_width,
<br>> ymin = -beam_height,
ymax = beam_height,
<br>> nx = 41,
<br>> ny = 41,
<br>> filename = "MatDet2.psd")
<br>> AT(0, 0, dist1+.501) RELATIVE a1 ROTATED (0,0,0) RELATIVE
a1
<br>>
<br>> COMPONENT sum2 = Monitor(
<br>> xmin = -beam_width,
xmax = beam_width,
<br>> ymin = -beam_height,
ymax = beam_height)
<br>> AT(0, 0, dist1+0.502) RELATIVE a1 ROTATED (0,0,0) RELATIVE
a1
<br>> /* end of monitoring transmitted beam... */
<br>>
<br>> /* Bragg reflected beam along a2 */
<br>> COMPONENT a2 = Arm()
<br>> AT (0, 0, 0) RELATIVE mono0 ROTATED (0, TTM, 0) RELATIVE
a1
<br>>
<br>> /* monitoring Brag reflected beam... */
<br>> COMPONENT psd3 = PSD_monitor(
<br>> xmin = -beam_width,
xmax = beam_width,
<br>> ymin = -beam_height,
ymax = beam_height,
<br>> nx = 41,
<br>> ny = 41,
<br>> filename = "MatDet3.psd")
<br>> AT(0, 0, dist2+0.001) RELATIVE a2 ROTATED (0,0,0) RELATIVE
a2
<br>>
<br>> COMPONENT sum3 = Monitor(
<br>> xmin = -beam_width,
xmax = beam_width,
<br>> ymin = -beam_height,
ymax = beam_height)
<br>> AT(0, 0, dist2+0.002) RELATIVE a2 ROTATED (0,0,0) RELATIVE
a2
<br>>
<br>> COMPONENT div3 = Divergence_monitor(
<br>> xmin = -beam_width,
xmax = beam_width,
<br>> ymin = -beam_height,
ymax = beam_height,
<br>> nh = 41,
<br>> nv = 41,
<br>> h_maxdiv = 2.0,
<br>> v_maxdiv = 2.0,
<br>> filename = "MatDet3.div")
<br>> AT(0, 0, dist2+0.004) RELATIVE a2 ROTATED (0,0,0) RELATIVE
a2
<br>> /* end of monitoring Bragg reflected beam... */
<br>>
<br>> END
<br>>
<br>> --------------------------------------------------------------------------------
<br>> _______________________________________________
<br>> neutron-mc mailing list
<br>> neutron-mc@risoe.dk
<br>> <a href="http://neutron.risoe.dk/mailman/listinfo/neutron-mc">http://neutron.risoe.dk/mailman/listinfo/neutron-mc</a>
<p>Hi again!
<p>Sorry for bothering everybody with my little problem on Friday.
<br>I was not aware of the fact that my components 'psd2' and 'sum2'
<br>which were supposed to monitor the beam transmitted through the
<br>monochromator caused the strange behaviour.
<br>Do I need to learn how to use 'groups' to avoid this effect?
<br>Thanks for reading my mail and for suggestions...
<br>I am assuming there is no simple fix to teach
<br>McStas to respond in a more 'natural' way...
<p>Thanks!
<p>Uli
<br>--
<br>Ulrich WILDGRUBER
<br>wildgrub@dxray.mpi-stuttgart.mpg.de
<br>wwwmf.mpi-stuttgart.mpg.de/abteilungen/dosch/dosch.html
<br>-----------------------------------------------------------------------------
<br>Max-Planck-Institut für Metallforschung | Technische Universität
München
<br>Heisenbergstr. 3
| ZWE Neue Forschungs-Neutronenquelle
<br>
| Instrumentierung
<br>D-70569 Stuttgart
| D-85747 Garching/München
<br>Tel.: (+49)-711-689-1900
| Tel.: (+49)-89-289-14681
<br>Fax.: (+49)-711-689-1902
| Fax.: (+49)-89-289-14666
<p>_______________________________________________
<br>neutron-mc mailing list
<br>neutron-mc@risoe.dk
<br><a href="http://neutron.risoe.dk/mailman/listinfo/neutron-mc">http://neutron.risoe.dk/mailman/listinfo/neutron-mc</a></blockquote>
<pre>--
What's up Doc ?
--------------------------------------------
Emmanuel FARHI, <A HREF="http://www.ill.fr/Computing/people/Farhi">http://www.ill.fr/Computing/people/Farhi</A> \|/ ____ \|/
CS-Group ILL4/156, Institut Laue-Langevin (ILL) Grenoble ~@-/ oO \-@~
6 rue J. Horowitz, BP 156, 38042 Grenoble Cedex 9,France /_( \__/ )_\
Work :Tel (33/0) 4 76 20 71 35. Fax (33/0) 4 76 20 76 48 \__U_/</pre>
</html>