1. Progress with Geant4 The issue of the longitudinal sigma as input parameter to the code is now sorted out -> results are in good agreement with Fluka and EGS4 The step size in now changed in the code: the output file will give energy deposition per 1 mm ( no need to change this in data analysis programs such as Root) Coating of the collimators was implemented in the computer program and will be used for various widths and different materials

4. Collimator box: Ti alloy Wedge: other materials z y z x 2 mm depth 10 mm depth Material Properties

5. 2 mm depth 10 mm depth Mesh size: (10x10x500) µm3

6. Ti alloy box with graphite wedges 2 mm depth 10 mm depth 250 GeV 250 GeV 500 Gev 500 GeV

7. Ti Alloy collimator coated with other materials dimensions of the overall collimator were kept constant (gap is not affected by coating): x = 38 mm y = 17 mm z = 21.4 mm Z = 122.64 mm θ = 324 mrad Dimensions of the inner part of the collimator made of Ti alloy: For 2 mm coating: x = 38 mm y = 15 mm z = 20.72 mm Z = 110 mm θ = 324 mrad

8. Coated collimators are now implemented in Geant4 • Different widths of the coating can be set in the program • Next plans are to study a variety of coating materials all having different widths -> look at energy deposition along z for each case