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Dear Serge,
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<div>On Jul 2, 2013, at 12:27 , Serge Duarte Pinto <<a href="mailto:S.C.DuartePinto@tudelft.nl">S.C.DuartePinto@tudelft.nl</a>></div>
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<div text="#000000" bgcolor="#FFFFFF">I am trying to simulate a spin precession setup that yields a spatial modulation pattern after an analyzer. The modulations clearly show up on the PSD_monitor (see screenshot), but curiously the downward swings go below
zero intensity! I wonder how that is possible, and what I could possibly do against it.
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<div>True, negative intensities does not sound completely right… :-) I will have a closer look at this together with Erik Knudsen who implemented most of the polarisation support.</div>
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<div>Is it correctly understood that the two included comps are your own codes?</div>
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<div text="#000000" bgcolor="#FFFFFF">I also do not understand the units of intensity: I send a million neutrons to an area of 5 cm^2, to get intensities of the order 10^-13…</div>
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<div>This one I should be able to explain: </div>
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<div>You are using Source_simple which by default has an intensity of 1 neutrons/sec/cm^2/(4*PI)/Å. </div>
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<div>In your instrument file I see that you assign a focusing to only 1x1cm at a distance of 100 m which brings your emitted intensity down to something like 1e-9, and distributed over your 1e6 rays, this easily gives the low intensities you are seeing.</div>
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<div text="#000000" bgcolor="#FFFFFF">I attach the instrument description, together with the components Foil_flipper_magnet and Analyser_ideal it depends on. And the result I get when I run it.<br>
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<div>Thanks, I will have a closer look.</div>
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<div>Best,</div>
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<div>Peter</div>
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