<html dir="ltr"> <head> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <style id="owaParaStyle">P { MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px } </style> </head> <body fPStyle="1" ocsi="0"> <div style="direction: ltr;font-family: Tahoma;color: #000000;font-size: 10pt;"> hi, Vesna<a></a><a></a><a></a>, Recently I need to do some simulations using Gate optical process. When I tested the example included in the Gate package I found that my result is different from the reference. The main problem is that the peak of the energy spectrum from my result is significantly higher than that from the reference, which is 9500 and 6000 respectively. I also found that Mr. Zhang, Long had reported the same problem last year, here is the link of his finding: <a href="http://permalink.gmane.org/gmane.comp.science.opengate.user/1993">http://permalink.gmane.org/gmane.comp.science.opengate.user/1993</a> I have tried several versions of Gate and Geant4<a></a><a></a><a></a>, including Gate 6.1, Geant<a></a><a></a><a></a> 4.9.3.p02<a></a><a></a><a></a>, CLHEP<a></a><a></a><a></a> 2.0.4.5; Gate 6.1, Geant<a></a><a></a><a></a> 4.9.4.p01<a></a><a></a><a></a>, CLHEP<a></a><a></a><a></a> 2.1.0.1; Gate 6.1, Geant<a></a><a></a><a></a> 4.9.4.p03<a></a><a></a><a></a>, CLHEP<a></a><a></a><a></a> 2.1.0.1; and even the old version Gate 4.0, Geant<a></a><a></a><a></a> 4.91.p03<a></a><a></a><a></a>, CLHEP<a></a><a></a><a></a> 2.0.3.2; From all those combination of Gate and Geant<a></a><a></a> the results are the same and don't match with the reference. Would you please take a look at this issue and provide some help? Thank you. Best regards, <a>Yuxuan</a><a></a><a></a> </div> </body> </html>