1. Absorber/vacuum windows and absorber assembly 1.Window Requirements 2.MICE experimental constraints 3.Welded vs. non-welded windows 4.Installation 5.Testing

2. Technical considerations 1)Manufacture 2)Handling 3)Measurement of window 4)Window helium leak test 5)Test assemblies – windows and test fixtures 6)Seal tests – at ambient temp (water) 7)Seal tests – at cryo temp (LN2) 8)Pressure tests – destructive and non destructive (H2O) 9)Window certification – separate from manifold 10)Absorber/vacuum chamber system assembly 11)Assembly certification – absorber and vacuum chamber

3. Current window design

4. FNAL Safety Requirements for Windows Absorber Windows Design: Internal WAMP = 25 psid FEA showing max. allowable stress < 0.25 UTS (this is waived by meeting the performance tests below) Material certification Window engineering/design drawing Tests: Room temperature tests per UG-100 of the ASME code and room temp. burst test. Liquid nitrogen test – burst test per UG-101 of the ASME code Note: The LH2 circuit safety relief system includes 2 valves with a 10psid set point. In addition, a PLC-controlled vent valve will be installed

5. FNAL Safety Requirements for Windows (2) Vacuum Windows Assumption: Design assumes that the beampipe attaches to absorber vacuum windows, therefore vacuum exists on both sides of the windows Design: Internal WAMP = 25 psid External MAWP = 15 psid FEA showing maximum allowable stress is <2/3 S y or < 0.4 S u Material certification Window drawing Tests: 1.Burst test 5 vacuum windows at room temp. to demonstrate a burst pressure of at least 75 psid for all samples. (pressure exerted on interior side of vacuum volume). 2.Non-destructive tests at room temperature: a.External pressure to 25 psid to demonstrate no failures: no creeping, yielding, elastic collapse/buckling or rupture b.Other absorber vacuum jacket testing to ensure its integrity

6. MICE experimental constraints Flange modification Window protrusion (handling) Non-bolt secured NO design constraint drives welded Instrumentation feedthrough non-welded decision Change over times Extract absorber assembly Remove /replace windows Reassembly certification – absorber and vacuum chamber

7. Procedure completed Procedure defined Welded vs. non-welded WeldedNon-welded Manufacture Handling Window measurement Window leak testing (LHe) Test assemblies (fixtures) Seal test (ambient – water) Seal test (cryo – LN2) Pressure tests (absorber) Pressure tests (vacuum) Window certification (absorber) Window certification (vacuum)

8. Installation scenarios Can still take advantage of component modularity:  Window manufacture/test/certification - NIU/IIT  Absorber manufacture - KEK  Absorber/window assembly & cert. - NIU/IIT  Vacuum vessel manufacture/connections - NIU/IIT/FNAL Assembly and certification of absorber and vacuum system should be done at RAL “Final” schedule and cost estimate can proceed if provisional decision about window is made… budget for 2002 NSF proposal is the default

9. Latest design

10. Absorber testing procedure Have yet to define the safety certification for assembled absorber manifold and vacuum vessel:  Window design and prototype certification (separate)  Leak checks  Pressure tests  Non- LH2, cryo certification tests  Stability check (instrumentation)  Controls need to be defined (FNAL/SLAC model?)  Filling/purging procedure established Safety guidelines need to be worked out for secondary vacuum volumes, evacuation mechanics.