1. The issue: A non-standard thin window design  No closed form expression for maximum stress vs. volume pressure  FEA (finite element analysis): geometry stress material strain volume pressure displacement LH2 Window tests } Procedure  Precision measurement of window  FEA predictions (non-elastic)  Performance measurement Strain gages Photogrammetry

2. Modified Torispherical integrated window and flange design (tapered detail at right). Machine parameters shown. Precision measurement of window and flange with CMM at FNAL Industrial Center. Absorber Window Design R rr  Minimize window thickness

3. Results so far  2 rupture tests (130 and 330 micron windows, 15 cm radius)  Preliminary agreement of strain and displacement measurement with elastic region FEA predictions  Systematic errors resolved  Establishing Photogrammetry as a measure of strain  2 nd rupture test confirmed FEA prediction  Manifold complete, clear windows made for flow test Progress The remaining program:  4 more rupture tests (on 330 micron windows)  2 additional windows for absorber  Cryo pressure test of windows/absorber  Safety valve test  Flow test  Decision on intelligent absorber instrumentation

4. Absorber:  6 windows manufactured 6 weeks  Rupture tests complete9 weeks  New FEA calculations4 weeks  Flow test complete6 weeks  Safety valve test complete9 weeks  Instrumentation feedthroughs worked out 11 weeks  Vacuum Enclosure for absorber11 weeks  Safety review13 weeks Timelines The LINAC test area:  “Phase I” civil engineering  Refrigeration system installed  Cryo plumbing and LH2 controls installed  Evacuation chamber built  Instrumentation:  strain: bolometry, laser, photogrammetry  Luminosity: bolometry, silicon  RF radiation: ?