<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px; margin-top: 0px; margin-bottom: 0px;" class=""><font face="Calibri,Helvetica,sans-serif" class=""><font face="Calibri,Helvetica,sans-serif,serif,EmojiFont" class="">Dear Gate Experts, </font></font></div><div style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px; margin-top: 0px; margin-bottom: 0px;" class=""><font face="Calibri,Helvetica,sans-serif" class=""><font face="Calibri,Helvetica,sans-serif,serif,EmojiFont" class=""><br class=""></font></font></div><div style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px; margin-top: 0px; margin-bottom: 0px;" class=""><font face="Calibri,Helvetica,sans-serif" class=""><font face="Calibri,Helvetica,sans-serif,serif,EmojiFont" class="">I've been facing difficulty to generate the positron range in water using the ion source. </font><font face="Calibri,Helvetica,sans-serif,serif,EmojiFont" size="3" class=""><span style="font-size: 12pt;" class="">For particle and ion source the positron range histogram should be same, but I am getting different histograms!</span></font><font face="Calibri,Helvetica,sans-serif,serif,EmojiFont" size="3" class=""><span style="font-size: 12pt;" class=""> Please advise me if I am missing some information on my macro.</span></font></font></div><div style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px; margin-top: 0px; margin-bottom: 0px;" class=""><font face="Calibri,Helvetica,sans-serif" class=""><font face="Calibri,Helvetica,sans-serif,serif,EmojiFont" class=""><br class=""></font></font></div><div style="margin-top: 0px; margin-bottom: 0px;" class=""><font class=""><font face="Calibri,Helvetica,sans-serif,serif,EmojiFont" style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px;" class="">I am simulating positron range in water with O15 & F18 particle source and ion source using GATE. I have not face any problem with particle source of O15 & F18, however I got different positron range using the ion source. </font><font face="Calibri,Helvetica,sans-serif,serif,EmojiFont" class=""><font face="Calibri, Helvetica, sans-serif" size="3" class="">Attached you will find what I have generated. Red circle in the histogram is problematic part! </font><font face="Calibri, Helvetica, sans-serif" size="3" class="">I see some strange feature in my histogram only using the ion source. </font></font><font face="Calibri,Helvetica,sans-serif,serif,EmojiFont" size="3" style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px;" class=""><span style="font-size: 12pt;" class="">I also tried to use </span></font><font face="Calibri,Helvetica,sans-serif,serif,EmojiFont" size="3" style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px;" class=""><span style="font-size: 12pt;" class="">gamma and electrons</span></font><font face="Calibri,Helvetica,sans-serif,serif,EmojiFont" size="3" style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px;" class=""><span style="font-size: 12pt;" class=""> filters but that has no effect on output.</span></font></font></div><div style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px; margin-top: 0px; margin-bottom: 0px;" class=""><font face="Calibri,Helvetica,sans-serif" class=""><font face="Calibri,Helvetica,sans-serif,serif,EmojiFont" class=""><br class=""></font></font></div><div style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px; margin-top: 0px; margin-bottom: 0px;" class=""><font face="Calibri,Helvetica,sans-serif" class=""><font face="Calibri,Helvetica,sans-serif,serif,EmojiFont" class="">Could you please take a look and suggest me what might be the cause of this strange feature? I would greatly appreciate your help. </font></font></div><div style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px; margin-top: 0px; margin-bottom: 0px;" class=""><font face="Calibri,Helvetica,sans-serif" class=""><font face="Calibri,Helvetica,sans-serif,serif,EmojiFont" class=""><br class=""></font></font></div><div style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px; margin-top: 0px; margin-bottom: 0px;" class=""><font face="Calibri,Helvetica,sans-serif" class=""><font face="Calibri,Helvetica,sans-serif,serif,EmojiFont" class="">Physics list I am using:</font></font></div><div style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px; margin-top: 0px; margin-bottom: 0px;" class=""><font face="Calibri,Helvetica,sans-serif" class=""><font face="Calibri,Helvetica,sans-serif,serif,EmojiFont" class=""><br class=""></font></font></div><div style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px; margin-top: 0px; margin-bottom: 0px;" class=""><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252);" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">/gate/physics/addProcess ElectronIonisation</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252);" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">/gate/physics/processes/ElectronIonisation/setModel StandardModel e+</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252);" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">/gate/physics/processes/ElectronIonisation/setModel StandardModel e-</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252);" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">/gate/physics/processes/ElectronIonisation/setStepFunction e+ 0.2 0.1 mm</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252);" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">/gate/physics/processes/ElectronIonisation/setStepFunction e- 0.2 0.1 mm</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252); min-height: 13px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252); min-height: 13px;" class=""># Do I need IonIonisation process? </div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252);" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">#/gate/physics/addProcess IonIonisation</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252);" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">#/gate/physics/processes/IonIonisation/setStepFunction GenericIon 0.1 0.02 mm</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252); min-height: 13px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252);" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">/gate/physics/addProcess Bremsstrahlung</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252);" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">/gate/physics/processes/Bremsstrahlung/setModel StandardModel e+</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252);" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">/gate/physics/processes/Bremsstrahlung/setModel StandardModel e-</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252); min-height: 13px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252);" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">/gate/physics/addProcess eMultipleScattering</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252);" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">/gate/physics/processes/eMultipleScattering/setGeometricalStepLimiterType e- distanceToBoundary</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252);" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">/gate/physics/processes/eMultipleScattering/setGeometricalStepLimiterType e+ distanceToBoundary</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252); min-height: 13px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252);" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">/gate/physics/addProcess PositronAnnihilation</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252); min-height: 13px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252);" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">/gate/physics/addProcess RadioactiveDecay</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252);" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">/gate/physics/addAtomDeexcitation</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252);" class=""><br class=""></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252);" class=""><span style="font-family: Calibri, Helvetica, sans-serif, serif, EmojiFont; font-size: 16px;" class="">I am using following cuts as well, but is has no effect on output.</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252);" class=""><br class=""></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; background-color: rgb(252, 252, 252);" class=""><div style="margin: 0px; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">/gate/physics/Gamma/SetCutInRegion world 1 mm</span></div><div style="margin: 0px; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">/gate/physics/Electron/SetCutInRegion world 1 mm</span></div><div style="margin: 0px; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">/gate/physics/Positron/SetCutInRegion world 1 mm</span></div><div style="margin: 0px; line-height: normal; min-height: 13px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""></span><br class=""></div><div style="margin: 0px; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">/gate/physics/Gamma/SetCutInRegion waterbox 0.05 mm</span></div><div style="margin: 0px; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">/gate/physics/Electron/SetCutInRegion waterbox 0.05 mm</span></div><div style="margin: 0px; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">/gate/physics/Positron/SetCutInRegion waterbox 0.05 mm</span></div><div style="margin: 0px; line-height: normal;" class=""><br class=""></div></div></div><div style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px; margin-top: 0px; margin-bottom: 0px;" class=""><font face="Calibri,Helvetica,sans-serif" class=""><font face="Calibri,Helvetica,sans-serif,serif,EmojiFont" class=""><br class=""></font></font></div><div style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px; margin-top: 0px; margin-bottom: 0px;" class=""><img height="545" width="773" apple-width="yes" apple-height="yes" apple-inline="yes" id="01CB7CFE-122B-4D08-9BE0-C9136070544F" src="cid:1A5B7703-4C93-4F48-A9F9-BE773085853D@healthcare.uiowa.edu" class=""><img height="582" width="626" apple-width="yes" apple-height="yes" apple-inline="yes" id="6BB5618D-CB2D-4B97-B7D2-AE96AAA348D0" src="cid:5CC6F3F5-9D5D-4859-9BBB-370A2BA847CE@healthcare.uiowa.edu" class=""><img height="505" width="773" apple-width="yes" apple-height="yes" apple-inline="yes" id="7290A541-7C03-4CBC-9E6A-DD6C18A42CA2" src="cid:B52DD46D-E9B3-4ED5-BCD9-863F6D95B448@healthcare.uiowa.edu" class=""></div><div style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px; margin-top: 0px; margin-bottom: 0px;" class=""><span style="font-family: Calibri, Helvetica, sans-serif, serif, EmojiFont;" class=""><br class=""></span></div><div style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px; margin-top: 0px; margin-bottom: 0px;" class=""><span style="font-family: Calibri, Helvetica, sans-serif, serif, EmojiFont;" class="">Thank you.</span></div><div style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px; margin-top: 0px; margin-bottom: 0px;" class=""><font face="Calibri,Helvetica,sans-serif" class=""><font face="Calibri,Helvetica,sans-serif,serif,EmojiFont" class=""><br class=""></font></font></div><div style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px; margin-top: 0px; margin-bottom: 0px;" class=""><font face="Calibri,Helvetica,sans-serif" class=""><font face="Calibri,Helvetica,sans-serif,serif,EmojiFont" class="">Regards,</font></font></div><div style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px; margin-top: 0px; margin-bottom: 0px;" class=""><font face="Calibri,Helvetica,sans-serif" class=""><br class=""></font></div><div id="Signature" style="font-family: Calibri, Helvetica, sans-serif; font-size: 16px;" class=""><font face="Calibri,Helvetica,sans-serif" class=""><div id="divtagdefaultwrapper" class=""><font face="Calibri,Helvetica,sans-serif,Helvetica,EmojiFont,Apple Color Emoji,Segoe UI Emoji,NotoColorEmoji,Segoe UI Symbol,Android Emoji,EmojiSymbols" size="3" color="black" class=""><span id="divtagdefaultwrapper" style="font-size: 12pt;" class=""><div align="justify" style="margin-top: 0px; margin-bottom: 0px;" class=""><font size="3" color="#757B80" class=""><span style="font-size: 12pt;" class=""><b class=""><u class="">Ashok Tiwari</u></b></span></font></div><div align="justify" style="margin-top: 0px; margin-bottom: 0px;" class=""><font size="3" color="#757B80" class=""><span style="font-size: 12pt;" class="">Graduate Research Assistant</span></font></div><div style="margin-top: 0px; margin-bottom: 0px;" class=""><font color="#757B80" class="">Department of Physics & Astronomy</font></div><div style="margin-top: 0px; margin-bottom: 0px;" class=""><font color="#757B80" class="">University of Iowa</font></div><div style="margin-top: 0px; margin-bottom: 0px;" class=""><font color="#757B80" class="">Iowa City, 52246, IA</font></div></span></font></div></font></div></body></html>