assembly.gdml

<?xml version="1.0" encoding="UTF-8" ?>
<gdml xmlns:gdml="http://cern.ch/2001/Schemas/GDML" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="http://service-spi.web.cern.ch/service-spi/app/releases/GDML/schema/gdml.xsd" >

<define>
  <constant name="HALFPI" value="pi/2."/>
  <constant name="PI" value="1.*pi"/>
  <constant name="TWOPI" value="2.*pi"/>
  <position name="center" x="0" y="0" z="0"/>
  <rotation name="identity" x="0" y="0" z="0"/>
  <rotation name="alignSurfX" y="HALFPI" />
  <rotation name="alignSurfY" x="HALFPI" />
</define>

<materials>

  <element name="Oxygen"   formula="O"  Z="8.">
    <atom value="16.0"/>
  </element>
  <element name="Nitrogen" formula="N"  Z="7.">
    <atom value="14.01"/>
  </element>

  <material name="Al" Z="13.0">
   <D value="2.70"/>
   <atom value="26.98"/>
  </material>

  <material name="Air">
   <D value="1.290" unit="mg/cm3"/>
   <fraction n="0.7" ref="Nitrogen"/>
   <fraction n="0.3" ref="Oxygen"/>
  </material>

</materials>

<solids>
  <box  name="WorldBox" x="1.0" y="1.0" z="1.0" lunit="m"/>
  <tube name="TubeSol" rmin="0.1075" rmax="0.1875" z="0.1875" deltaphi="TWOPI" startphi="0" aunit="rad" lunit="m"/>
</solids>

<structure>

  <volume name="TubeVol">
    <materialref ref="Al"/>
    <solidref ref="TubeSol"/>
  </volume>

  <assembly name="AssemblyVol">
    <physvol>
      <volumeref ref="TubeVol"/>
      <position name="pos1" unit="m" x="0" y="0" z="0.5"/>
      <rotationref ref="alignSurfX"/>
    </physvol>
    <physvol>
      <volumeref ref="TubeVol"/>
      <position name="pos2" unit="m" x="0" y="0" z="-0.5"/>
      <rotationref ref="alignSurfY"/>
    </physvol>
  </assembly>

  <volume name="World">
    <materialref ref="Air"/>
    <solidref ref="WorldBox"/>
    <physvol>
       <volumeref ref="AssemblyVol"/>
       <positionref ref="center"/>
       <rotationref ref="identity"/>
    </physvol>
  </volume>

</structure>

<setup name="Default" version="1.0">
  <world ref="World"/>
</setup>

</gdml>