Energy Deposition Group
The Energy Deposition Group of the Accelerator Integration Department is collaborating with groups from SLAC, BNL and RHUL in the study of three related issues for the ILC:

• Energy deposition and collimation for design of the beam delivery system and the interaction regions,
• Backgrounds in the detectors and their mitigation,
• Treatment of the spent beams downstream of the interaction points.

During FY05 a MARS15 calculation model was generated including geometry, materials and magnetic fields over 2 kilometers of beam line, including the 1.5-km beam delivery system, the interaction point (IP) and experiments, and the 0.5-km region downstream of the IP for stopping the spent beams. This model is used to study beam impact to accelerator equipment and operation (quenching, cryogenic load, and radiation damage/activation), to the experiments, and to the environment. A preliminary specification for the collimation system was prepared. Initial estimates of experimental backgrounds were studied.

The next steps will be:

• A refinement of the geometric, magnetic, and physic models.
• The first attempt to minimize backgrounds and radiation loads to the experiments and radiation loads to machine components.
• The first application of real engineering constraints to the design study and optimizations.