Light Guide Information

References to Simulation

1. Path to repository for GEANT3 routines (Elton):
   • The code I have used to compute light guide collection acceptances for the Bcal (See GlueX-doc-1077 and GlueX-doc-959) are stored under svn at svn ls https://halldsvn.jlab.org/repos/trunk/home/elton/geantguide The original code came from Blake (UofR) and modified to suit my application. If anyone wants to use it they should contact me for more details. My own suggestion to begin light guide simulations would be to find out more about IU's GEANT4 stand-alone simulations. There are some updates on reflectivities that are more realistic than the ones in GEANT3 (Matt?).
2. GEANT4 routines (Beni):
   • I put some version of the code developed at IU to the svn repository: svn ls https://halldsvn.jlab.org/repos/trunk/home/zihlmann/BCAL has two directories for a code running in bach mode and a version that can be run in batch mode or interactive using a gui.
3. GUIDEIT
   • Code: get it from GUIDEIT
   • Fiber simulation on portal; this is a comprehensive report for light propagation down our fibers, and explains the use of all the GUIDEIT switches/flags.

Prototypes from Plastic Craft

• Twelve light guides arrived from Plastic Craft on Friday April 1, 2011. They correspond to the light guides that form the inner twelve locations on a single wedge.
  

Single guide with quarter for scale

Twelve guide arrangement

Guide#12 with chip

Dimensions / comments

• Dimensions of Light Guides
• Histogram of dimensions relative to nominal
• Note that dimensions of the widths have some additional uncertainty since they are being measured on an angled surface.
• Both light guides #11 seem to have a discoloration (tan/brown) compared to the other ones (can be noted in the enlarged picture of the arrangement above).
• One of the light guides #12 has a small chip near the base

Quick transmission measurement

Test Setup