<div dir="ltr"><div><div><div><div><div>Hi Zeinab Telikani,<br><br></div>I've had the same problem before, try to use the volume "trap" instead of "trpd", for eg.:</div><div><br></div>/gate/world/daughters/name SPECThead <br>/gate/world/daughters/insert trap <br>/gate/SPECThead/geometry/setDx1 26.73 mm <br>/gate/SPECThead/geometry/setDx2 26.73 mm <br>/gate/SPECThead/geometry/setDz 10.85 mm <br>/gate/SPECThead/geometry/setTheta 0.00 deg <br>/gate/SPECThead/geometry/setDy1 50.00 mm <br>/gate/SPECThead/geometry/setDy2 50.00 mm <br>/gate/SPECThead/geometry/setDx3 23.99 mm <br>/gate/SPECThead/geometry/setDx4 23.99 mm <br>/gate/SPECThead/geometry/setPhi -90.00 deg <br>/gate/SPECThead/geometry/setAlp1 0.00 deg <br>/gate/SPECThead/geometry/setAlp2 0.00 deg <br>/gate/SPECThead/setMaterial Air <br>/gate/SPECThead/placement/setTranslation 0.00 0.00 -200.75 mm <br>/gate/SPECThead/repeaters/insert ring <br>/gate/SPECThead/ring/setRepeatNumber 2<br>/gate/SPECThead/ring/setPoint1 0. 1. 0. mm <br>/gate/SPECThead/ring/setPoint2 0. 0. 0. mm <br><br></div>For more information on the volume parameters, look for "Generic trapezoid" on this website:<br><a href="https://geant4.web.cern.ch/geant4/UserDocumentation/UsersGuides/ForApplicationDeveloper/html/ch04.html">https://geant4.web.cern.ch/geant4/UserDocumentation/UsersGuides/ForApplicationDeveloper/html/ch04.html</a><br><br></div>Regards,<br></div>Débora<br><div><div><br clear="all"><div><div><div><div><div><div><div><div class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><span style="border-collapse:separate;color:rgb(0,0,0);font-family:Helvetica;font-style:normal;font-variant:normal;font-weight:normal;letter-spacing:normal;line-height:normal;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;border-spacing:0px"></span><span style="color:rgb(7,55,99)"><span style="font-family:tahoma,sans-serif"></span><span style="font-family:tahoma,sans-serif">Debora Salvado, PhD</span></span><br><span style="color:rgb(7,55,99)"><span style="font-family:tahoma,sans-serif">University College London UCLH</span></span><span style="color:rgb(7,55,99)"><span style="font-family:tahoma,sans-serif"><br></span></span><span style="color:rgb(7,55,99)"><span style="font-family:tahoma,sans-serif">London </span></span><span style="color:rgb(7,55,99)"><span style="font-family:tahoma,sans-serif">UK</span></span><span style="color:rgb(12,52,61)"><span style="font-family:tahoma,sans-serif"></span></span></div><div><br></div><div><br>------------------------------</div><div>Message: 1<br>
Date: Wed, 4 Oct 2017 21:01:08 +0000 (UTC)<br>
From: zeinab TELIKANI <<a href="mailto:telikani_z@yahoo.com">telikani_z@yahoo.com</a>><br>
To: "<a href="mailto:gate-users@lists.opengatecollaboration.org">gate-users@lists.<wbr>opengatecollaboration.org</a>"<br>
        <<a href="mailto:gate-users@lists.opengatecollaboration.org">gate-users@lists.<wbr>opengatecollaboration.org</a>><br>
Subject: [Gate-users] Problem in modeling a trapezoid<br>
Message-ID: <<a href="mailto:1301386339.1506259.1507150868833@mail.yahoo.com">1301386339.1506259.<wbr>1507150868833@mail.yahoo.com</a>><br>
Content-Type: text/plain; charset="utf-8"<br>
<br>
Hi GATE users<br>
I have modeled a trapezoid as the collimator in my 
SPECTsimulation.Everything seems to be right, but, I have faced an 
unexpectedproblem: an extra volume existsinside the trapezoid (as shown 
in attached figure).Hereare the commands used to define aforementioned 
trapezoid:<br>
<br>
# Collimator (Trapezoidal Collimator)<br>
/gate/world/daughters/name collimator/gate/world/<wbr>daughters/insert trpd/gate/collimator/geometry/<wbr>setX1Length 0.7 cm/gate/collimator/geometry/<wbr>setY1Length 0.7 cm/gate/collimator/geometry/<wbr>setX2Length 9 cm/gate/collimator/geometry/<wbr>setY2Length 5 cm/gate/collimator/geometry/<wbr>setZLength 5 cm<br>
/gate/collimator/setMaterial Lead/gate/collimator/vis/<wbr>setColor red/gate/collimator/vis/<wbr>forceWireframe<br>
 Any suggestion or ideawould be appreciated; thank you in advance.</div></div></div></div></div></div></div></div></div></div></div></div>
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