Bubble Chamber Beam Test September 2015

Run Plan

• To-do List:

1. Geometry is in gdml format, need to get correct Radiator, Collimator, Beamline, PhotonDump geometry.
2. Add sweep magnet and electrondump geometry in gdml format.
3. Complete: Include the Bubble Chamber geometry using the Bubble Chamber STEP file (change .txt to .stp): media:BubbleChamber.txt.
   1. Geometry has been created and is on github, BubbleMother.gdml and all daughter files
4. The beamline STEP file will be ready very soon. When? Last file recieved was BubbleChamber again 6_24_2014.
5. GEANT4 uses models that calculate wrong photo–nuclear cross sections (see below). GEANT4 does not allow for user’s cross sections. What to do?
   1. Use GEANT4 to produce the photon spectra impinging on the superheated liquid.
   2. Fold the above photon spectra with our cross sections in stand-alone codes.
   3. Could we not create a correct physicslist.cc in geant4 instead?

• GEANT4 Photon-Inelastic Model: CHIPS Gamma Nuclear has this cross section for our reaction:

• The simulation below is outdated and doesnt work with gdml. See github for correct version.
• Quick start for the simulation: media:G4_BubbleEx_README.txt. There is also a README file that comes with the example.
• Bubble Chamber GEANT4 Example (change .txt to .tar): media:BubbleEx96.txt

Compiling/Running Simulation (BubbleEx)

• Using the ifarm or jlabl4 nodes