<html><head><meta http-equiv=Content-Type content="text/html; charset=utf-8"><META name="Author" content="Novell GroupWise WebAccess"></head><body style='font-family: Tahoma, sans-serif; font-size: 13px; background-color: #fff;'>Hello Masoud,<br><br>I may be wrong, but this is how I believe it works. Each point you define is the energy value in MeV, then the height of that point. So you need to define your spectrum, say for an energy distribution from 0-1MeV for example:<br><br>/gate/source/xraygun/gps/histpoint 0.1 0.005<br>/gate/source/xraygun/gps/histpoint 0.2 0.01<br>/gate/source/xraygun/gps/histpoint 0.3 0.03<br>/gate/source/xraygun/gps/histpoint 0.4 0.7<br>/gate/source/xraygun/gps/histpoint 0.5 1.0<br>/gate/source/xraygun/gps/histpoint 0.6 1.0<br>/gate/source/xraygun/gps/histpoint 0.7 0.7<br>/gate/source/xraygun/gps/histpoint 0.8 0.03<br>/gate/source/xraygun/gps/histpoint 0.9 0.01<br>/gate/source/xraygun/gps/histpoint 1.0 0.005<br><br><br>From what I see in the forums, people have given the second value either as a normalized value (like I have done with the peak at 1.0), or as actual data (in this case, I suppose the distribution would be automatically normalized?).<br><br>I'm going off the forums from here:<br><a href="http://thread.gmane.org/gmane.comp.science.opengate.user/88/focus=92">http://thread.gmane.org/gmane.comp.science.opengate.user/88/focus=92</a><br><br>Can someone confirm what I've explained, or correct me if I'm way wrong?<br><br><br><br><br><br><br/><div style='clear: both;'>Cheers,<BR>Devin Van Elburg<BR>------------------------<BR>Physics w/ c/ Biomedical Physics<BR>Lakehead University</div><br/>>>> Masoud <masoud11270@yahoo.com> 08/20/15 11:57 AM >>><br>
<div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:18px"><div class="" id="yiv6374552518yui_3_16_0_1_1439882981528_2730" style="font-family: 'bookman old style', 'new york', times, serif; font-size: 16px;">Dear all,</div><div class="" id="yiv6374552518yui_3_16_0_1_1439882981528_2730" style="font-family: 'bookman old style', 'new york', times, serif; font-size: 16px;"><br id="yui_3_16_0_1_1440087933563_5509" class=""></div><div class="" id="yiv6374552518yui_3_16_0_1_1439882981528_2734" style="font-family: 'bookman old style', 'new york', times, serif; font-size: 16px;">I am trying to simulate a CT scanner. For source definition, I need to use arbitrary point-wise spectrum "Arb" as following command:</div><div class="" id="yiv6374552518yui_3_16_0_1_1439882981528_2734" style="font-family: 'bookman old style', 'new york', times, serif; font-size: 16px;"><br id="yui_3_16_0_1_1440087933563_5513" class=""></div><div class="" id="yiv6374552518yui_3_16_0_1_1439882981528_2738" style="font-family: 'bookman old style', 'new york', times, serif; font-size: 16px;">/gate/source/xraygun/gps/histpoint energy (MeV) ????</div><div class="" id="yiv6374552518yui_3_16_0_1_1439882981528_2738" style="font-family: 'bookman old style', 'new york', times, serif; font-size: 16px;"><br id="yui_3_16_0_1_1440087933563_5517" class=""></div><div class="" id="yiv6374552518yui_3_16_0_1_1439882981528_2742" style="font-family: 'bookman old style', 'new york', times, serif; font-size: 16px;">Please guide me what is the second column in the command? Photon fluence (photon/mm2.s)? or photon flux (photon/s)? or number of photons in source?</div><div class="" id="yiv6374552518yui_3_16_0_1_1439882981528_2742" style="font-family: 'bookman old style', 'new york', times, serif; font-size: 16px;"><br id="yui_3_16_0_1_1440087933563_5521" class=""></div><div class="" id="yiv6374552518yui_3_16_0_1_1439882981528_2746" style="font-family: 'bookman old style', 'new york', times, serif; font-size: 16px;">Best Regards,</div><div id="yiv6374552518yui_3_16_0_1_1439882981528_2722" style="font-family: 'bookman old style', 'new york', times, serif; font-size: 16px;" class=""></div><div class="" dir="ltr" id="yiv6374552518yui_3_16_0_1_1439882981528_2750" style="font-family: 'bookman old style', 'new york', times, serif; font-size: 16px;">Masoud</div></div></masoud11270@yahoo.com></body></html>