Pb Cylinder (AKA "Temp Shield")

Creating Lead Cylinder

For a lead cylinder with outer radius of 60mm, to ensure Moller electrons can clear the material:

[math]tan\ \theta=\frac{60\ mm}{d} \Rightarrow d=\frac{60\ mm}{tan\ 5 \circ} \approx 685\ mm[/math]

Since the Geant4 solid is based on it's half-distance with respect to the origin, we need to add 6000 to this to find the starting distance.

Geometry files follow the format:

Name: No Spaces
Mother: root if primary component
Description: Short explaination
Position: The center of the object wrt to the vertex
Rotation:0*deg 0*deg 0*deg
Type: G4 Tube
Dimensions: Inner Radius, Outer Radius, Half-Length in z, starting phi position angle of segment ,delta phi angle of segment
Material: Defined in materials file
Color:The color entry is a 6 digit hexadecimal number that represents Red, Green and Blue weights from 0 to 255 each in the form: RRGGBB
Visible: 1=Yes, 0=No
Style:1=Solid,0=Wireframe

Geometry File

File:PbCylinder geometry basic.txt

Material File

File:PbCylinder materials basic.txt

Modified gcard line

       <detector name="/home/lds/src/CLAS/GEMC/clas12Tags/4a.2.2/experiments/clas12/PbCylinder/PbCylinder"          factory="TEXT" variation="basic"/>

Gemc Visual

Trial Run

~/src/CLAS/GEMC/clas12Tags/4a.2.2/source/gemc -USE_GUI=1 -BEAM_P="e-, 11.0*GeV, 5.0*deg, 10*deg" -BEAM_V="(0, 0, 0)cm" -N=1 eg12.gcard