RAD – The Radiation Assessment Detector for MSL Seimetz DLR November 30 – December 1, 2006 RSH Packaging Peer Review 1 16 – Machining Issues & Discussion Lars Seimetz, CAU, Kiel, Germany RSH Packaging Peer Review

RAD – The Radiation Assessment Detector for MSL Seimetz DLR November 30 – December 1, 2006 RSH Packaging Peer Review 2 Content BC430m/BC432m Magnesium

RAD – The Radiation Assessment Detector for MSL Seimetz DLR November 30 – December 1, 2006 RSH Packaging Peer Review 3 Scintillation Detectors BC430 from St.Gobain used on xxx BC430m with improved temp. behaviour ordered, but complete first lot wrong due to wrong composition. Second lot (  now called BC43 2 m) in House and currently being tested. –Enough Material for 3 complete RSH Anticoincidence Sets –First test show better temperature behaviour (stable up to 75°C, details from Sönke)

RAD – The Radiation Assessment Detector for MSL Seimetz DLR November 30 – December 1, 2006 RSH Packaging Peer Review 4 Handling of BC430m (BC432m) Challenging Manufacturing Process due to big internal stresses  Great Heat has to be avoided – notedly slow manufacturing necessary  Great Cooling has to be avoided – cleaning with soft alcohol  Avoid additional Stress – Special design criteria for mechanical Design  Special Polishing Material  Optical Degradation of Material over time ?  Inclusions in Material from manufacturing process only become visible after polishing

RAD – The Radiation Assessment Detector for MSL Seimetz DLR November 30 – December 1, 2006 RSH Packaging Peer Review 5 Magnesium Completely new Manufacturing-Zone in machine shop High Security Regulations for Mg-Machining Special Exhaust System Special Metal Fire Extinguisher Permanent Oil Cooling (…) Special Handling Procedures Complex Swarf Collection and Waste Management „Pathfinder“ Magnesium Housing currently manufactured –Material with greater internal stresses  Dimensional stability inferior to aluminium  Mechanical tolerances have to be adjusted / Stress-Reliefed Material?