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<p class=MsoNormal>Hello all,<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>I have a question concerning the Source_Adapt component and
its energy (or wavelength) distribution. My simplified understanding is
that this component initially emits a uniform energy (or wavelength)
distribution, then throughout a simulation adapts this distribution to increase
counts in the adapt_check component. However, I am having a problem
getting an initial uniform distribution in wavelength, in fact, it seems as
though the distribution models some sort of exponential decay between E0 –dE
and E0 + dE. In order to test this, I did two things. I first set
up a simulation where no adaptation in energy was required by creating a simple
instrument with a Source_Adapt, two slits, a collimator and an adapt_check, I’ve
attached a file showing the wavelength distribution from an L_monitor placed
right after the source (pos1_plot.jpg). I then added a powder
sample to the previous instrument and moved the adapt_check behind it, but set
beta = 1 on the source_adapt (to force the component to distribute all neutrons
uniformly among all bins, i.e. no adaptation). The wavelength
distribution seen from the source is in pos2_plot.jpg and it the same as the
previous.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Here is the component definition for the Souce_Adapt in my
instrument:<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>COMPONENT source = Source_Adapt(<o:p></o:p></p>
<p class=MsoNormal> N_E = 20, N_xpos = 20, N_xdiv = 20, xmin
= -0.005,<o:p></o:p></p>
<p class=MsoNormal> xmax = 0.005, ymin = -0.005, ymax =
0.005, dist = 6.134,<o:p></o:p></p>
<p class=MsoNormal> xw = 0.01, yh = 0.01, E0 =180, dE = 172,
alpha = 0.25,<o:p></o:p></p>
<p class=MsoNormal> beta = 0.25)<o:p></o:p></p>
<p class=MsoNormal> AT (0, 0, 0) RELATIVE origin<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>E0 and dE chosen to distribute wavelengths between approximately
0.5AA and 3.2AA.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>What would like is for the Source_adapt to initially give a
uniform distribution, much like the Source_Simple component. Is
this possible with my current parameters for E0 and dE?<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Regards,<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Aaron<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New"'>*************************************************</span><span
lang=EN-US style='font-size:12.0pt;font-family:"Courier New"'><o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New"'>Aaron
M. Percival<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New"'>M.Sc.
Candidate<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New"'>Dept.
of Physics, Engineering Physics & Astronomy<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New"'>Queen's
University<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New"'>Kingston,
Ontario, Canada, K7L 3N6<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New"'>Office:
613-533-6000 ext. 74789<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New"'>Fax:
613-533-6463<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New"'>*************************************************<o:p></o:p></span></p>
<p class=MsoNormal><o:p> </o:p></p>
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