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<p class="MsoNormal">Hi all, <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> <span lang="EN-US">In addition/complement to Maurik’s plot which demonstrate the point, here are 2 more graphs: for electrons tracks in the horizontal plane, E vs position on ECal front face, with angle of incidence color
coded. Angle of incidence is track angle on ECal – crystal angle (which explains the vertical structures since the crystal angles are discretized). Generated with wide angle range at target. Negative x is to the right of ECal (electron side).<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">First graph is with the condition that the track does not hit the vacuum chamber at any point between target and magnet exit. At 2.2 GeV, there are no tracks above x = 200 mm ! (see Note)<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Second graph is with the additional condition that at least 4 SVT planes are hit.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"> Note that for 2.2 GeV (top of graph) the incident angles are nearly symmetrical, so that the shower develops at +/- 6 degrees wrt to the crystal. That would be my explanation for Luca’s yellow crystals,
because the seed hit is a lesser fraction of the total. To be absolutely sure (and to distinguish with Maurik’s hypothesis), one would have to plot the total cluster energy (complete cluster with JLab algorithm). In Maurik’s hypothesis, it degrades in the
yellow crystals, in mine not.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"> Michel.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Note: This is from my own simulation; there might be (in fact there are) small differences with SLIC geometry, of the order of a few mm to 1 cm on various distances.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><b><i><span style="font-size:9.0pt;font-family:"Bookman Old Style","serif";color:#4F81BD;mso-fareast-language:FR">_______________<o:p></o:p></span></i></b></p>
<p class="MsoNormal" style="text-autospace:none"><b><i><span style="font-size:9.0pt;font-family:"Bookman Old Style","serif";color:#4F81BD;mso-fareast-language:FR">Michel Garçon<o:p></o:p></span></i></b></p>
<p class="MsoNormal" style="text-autospace:none"><i><span style="font-size:9.0pt;font-family:"Bookman Old Style","serif";color:#4F81BD;mso-fareast-language:FR">Irfu/SPhN
<o:p></o:p></span></i></p>
<p class="MsoNormal" style="text-autospace:none"><i><span style="font-size:9.0pt;font-family:"Bookman Old Style","serif";color:#4F81BD;mso-fareast-language:FR">CEA-Saclay, bât. 703
<o:p></o:p></span></i></p>
<p class="MsoNormal" style="text-autospace:none"><i><span style="font-size:9.0pt;font-family:"Bookman Old Style","serif";color:#4F81BD;mso-fareast-language:FR">91191 Gif-sur-Yvette cedex
</span></i><span style="font-size:12.0pt;font-family:"Times New Roman","serif";color:#4F81BD;mso-fareast-language:FR"><o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><i><span style="font-size:9.0pt;font-family:"Bookman Old Style","serif";color:#4F81BD;mso-fareast-language:FR">France
</span></i><i><span style="font-size:12.0pt;font-family:"Bookman Old Style","serif";color:#4F81BD;mso-fareast-language:FR"> </span></i><i><span style="font-size:10.0pt;font-family:"Bookman Old Style","serif";color:#4F81BD;mso-fareast-language:FR"><o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:8.0pt;font-family:"Bookman Old Style","serif";color:#4F81BD;mso-fareast-language:FR">Tél.:</span></i><i><span style="font-size:9.0pt;font-family:"Bookman Old Style","serif";color:#4F81BD;mso-fareast-language:FR">
+33 1 69 08 86 23</span></i><span style="mso-fareast-language:FR"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:FR"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><u><span lang="EN-US" style="font-size:9.0pt;font-family:"Bookman Old Style","serif";color:#4F81BD;mso-fareast-language:FR">Until October 31st, on leave at<o:p></o:p></span></u></p>
<p class="MsoNormal" style="text-autospace:none"><i><span lang="EN-US" style="font-size:9.0pt;font-family:"Bookman Old Style","serif";color:#4F81BD;mso-fareast-language:FR">Jefferson Lab<o:p></o:p></span></i></p>
<p class="MsoNormal" style="text-autospace:none"><i><span lang="EN-US" style="font-size:9.0pt;font-family:"Bookman Old Style","serif";color:#4F81BD;mso-fareast-language:FR">Office in CC-B129<o:p></o:p></span></i></p>
<p class="MsoNormal" style="text-autospace:none"><i><span style="font-size:9.0pt;font-family:"Bookman Old Style","serif";color:#4F81BD;mso-fareast-language:FR">Phone : +1 757 269 7636<o:p></o:p></span></i></p>
<p class="MsoNormal"><o:p> </o:p></p>
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