BAM Activity at CERN

1. OPERA Collaboration meeting LNGS, May 20th , 2003 BAM Activity at CERN S. Buontempo, G. Decreuse, J. Dupraz, C. Schillinger New welding tools Alternative folding brick: dimension measurements Leakage test measurements in destructive mode Pressure test measurements on pile Outlooks

2. New welding tool from Sidec firm Manual welding clamp with 2 heating sides and possibility to adjust: - welding heating time, - welding cooling time pressure depends from operator Welding machine with 1 heating side, with vacuum chamber and Possibility to adjust: - welding heating time, - welding cooling time pressure is fixed at 1 bar

3. Modified welding tool • We modified the manual welding clamp and • now we can control and adjust the pressure • and start with external switch: • the closure of clamp (at set pressure), • the welding (heating of the clamp), • the vacuum (with slow ramping).

4. Modified welding tool We have performed preliminary test measurements on envelopes done with different laminate films (Nagoya, Sidec FA30, Sidec 122TLS95), with T and without T points. • The possibility to adjust welding parameters has showed us that • we have the best welding performance working at: • 2 sec heating time • 6 sec cooling time • 5 bar pressure on the clamp

5. New welding tool • With the possibility to perform vacuum in • a chamber we have checked the performance • of welding inside vacuum environment. • The welding clamp here is heating on a single • side and the opposite one is a silicon strip. • The pressure is 1 bar (not adjustable) and we • have found the best welding conditions at • 1.2 sec heating time • 2 sec cooling time • We are in contact with Sidec firm to apply • changes on these welding conditions

6. Alternative folding packaging We know that the weaker part of the ECC packaging with laminated film is the zone with overlapping of two welding lines (so called T point) Some of the pre-selected firms have proposed an Alternative packaging without T point.

7. Alternative folding packaging • This kind of packaging can be done with several configurations having: • different positions of the folded parts, • and/or different positions of welding lines

8. Alternative folding packaging After some brain storming we have chosen the following configuration to start measurements: Folded parts on side and bottom Welding lines on top and sides

9. Alternative folding packaging Preliminary measurements on the new brick shape: Brick high Brick length We made a tool to pull the laminated film while welding in order to minimize the extra material on the corners

10. Alternative folding packaging Measurements on 2 Al bricks wrapped with 0.2 mm PE film (nominal high 103.5mm): • Pos. brick n.1 n.2 • 1 -149 +151 • +64 +264 • +426 + 567 • -158 +152 • +254 +518 • +528 +650 6 5 4 3 2 1 We have seen that points 2, 3, 5, 6, reduce with pressure (there is air gap there in the folded parts) VERY PRELIMINARY

11. Alternative folding packaging Measurements on 2 Al bricks wrapped with 0.2 mm PE film (nominal high 125 mm): • Pos. brick n.1 n.2 • base • 1 +158 +151 • +305 +053 • +380 - 096 • top • 4 +720 +320 • 5 +1470 +1540 • 6 +440 +130 3 2 1 6 5 4 Points 4, 5, 6, reduce with pressure (air gap there in the folded parts) We could partially compensate this by skates and by PE, 0.2 mm thinner that carton paper VERY PRELIMINARY

12. Leakage measurements: set up Step 1: we make a brick with Al block or real pile, we packed with carton (or PE) and laminated film under vacuum, and then we make a hole Step 2: we make vacuum again inside the brick using the mass spectrometer pump Step 3: we inject He around the brick and see the amount measured by the mass spectrometer

13. Leakage measurements: materials and configurations • We have performed test measurements on different configurations: • envelopes (with T and without T) • Baseline bricks with carton or PE inside • Baseline no T bricks with carton or PE inside • We have used different materials: • Laminated films - Sidec FA30, Sidec122TLS95 (softer than FA30 with same low gas permeability), Nagoya film • Inside wrapping - Carton paper and PE • All test measurements have been performed with 5 min measurement time on mass spectrometer

14. Leakage measurements: results Sidec 122TLS 95 Envelopes (no T) with 0.2 mm PE film inside This shows that we have a good control of welding procedure and that laminated film is high quality

15. Leakage measurements: results AL bricks done in baseline mode (with T) with Sidec laminated film 122TLS 95 and carton paper

16. Leakage measurements: results AL bricks done in baseline mode (with T) with Sidec laminated film FA30 and carton paper FA30 is also good in terms of permeability but it is mechanically harder than 122TLS95 giving worst brick shapes

17. Leakage measurements: results Envelopes done with Nagoya film and carton with T No T No Leakage

18. Leakage measurements: results AL bricks done in baseline mode (with T) with Nagoya film and carton Important leakage in T point (confirming preliminary data reported in Strasbourg meeting)

19. Leakage measurements: results Al bricks done in baseline mode (with T) with Nagoya film (starting from envelopes done by GRT firm) and carton Much lower leakage (on envelopes 2 of 3 welding lines are done in industrial mode with larger welding line and with a rolling device)

20. Leakage measurements on a real pile brick Pile bricks done in envelope mode (no T) with Sidec film 122TLS 95 and PE (replacing carton) No He injected In first 30 min the mass spectrometer measures a leak After 135 min we find no leakage even with He injection. So the brick did not leak, but there was residual air inside

21. Leakage measurements: conclusions • Envelopes: • we do not find big difference in between T and no T mode • for all tested laminated films. In empty envelopes there is not the • mechanical stress on T point like in bricks • Al Bricks: • - with all Sidec films we find low leakage 5 x 10-10 (new 122TLS95 is • much better in terms of mechanical flexibility) • with Nagoya film we find large leakage 1 x 10-8 in T point • using Nagoya film envelopes done by GRT firm we find low • leakage ~7 x 10-10 • Pile brick: • Preliminary measurement (lack of material !) show that the pile traps • air inside which demands for 30 min to be purged out. • Further study is needed on pressed piles

22. Pressure test measurements on pile Some of the pre-selected firms have raised the problem of residual air inside the pile. They propose to purge it applying pressure. We have started some test measurements with hydraulic pump with pressure range up to 700 kg/cm2

23. Pressure test measurements on pile In order to evaluate the pile squeezing we performed a differential measurement with respect to the deformation of the table of the machine, raising up to 100 kg/cm2 permanent reduction, lost since the beginning, confirmed even after wrapping with adhesive tape

24. Pressure test measurements on pile Performing the test we learned the following information • Applying pressure ~ 100 kg/cm2 the pile (or • parts of it) get sticky. • This may depend from the: • vacuum sucking effect of removing air, • residual lamination oil, • painted lead, • stickiness of emulsion films • This could help the BAM procedure but we • have to evaluate if it is dangerous for • emulsion sheets. We need to repeat these tests with final lead and emulsion sheets

25. Pressure test measurements on pile With pile under pressure (70 kg/cm2) with - 0.58 mm squeezing effect we wrapped it with adhesive tape (as proposed by some firms): 3M R425 XT-8015 (0.13 mm Al with silicon glue, certified zero degassing) This could replace carton or PE in baseline option or could be a hermetic and light tight packaging on top of which we can apply mechanical pressure (alternative solution) …moreover

26. Pressure test measurements on pile After wrapping the pile goes back to - 0.43 mm squeezing and it becomes “solid” ! This could also simplify a lot all the pile manipulation during the BAM procedure before packaging We need to repeat these tests with final lead and emulsion sheets

27. BAM Activity at CERN: Conclusions and Outlook New welding devices have been received and modified. More experience has been done on welding procedure and leakage rate measurements. A new laminated film 122TLS95 from Sidec has been testes: positive results in terms of leakage. Sidec firm is producing a customized 122TLS95 film with addition of PE photo black inside and aluminized PE outside. Delivery expected in mid june. We have started studies on Brick packaging with no T point. Preliminary measurements on dimension show an increasing of brick High and length. More precise evaluation is needed for more statistic and possible sources of compensation (skate shape, PE replacing carton etc etc) Preliminary study of pile compression have started.

28. BAM Activity at CERN: Conclusions and Outlook • Additional measurements needed on: • on brick size, (baseline T and no T, with new laminated film and alternative packaging) • on pile bricks in destructive mode (Pb and emulsion urgently needed) • using final laminated film solution (custom for OPERA from Sidec) • performing He injection in the brick • on leakage rate in non destructive mode • Alternative packaging film tests: mechanical performance, ECC dimension uniformity, performance of wrapping with adhesive tape, • pressure measurements on pile • Welding: test on new tools, modifications on vacuum chamber machine to apply same conditions on modified manual clamp • BAM firm selection: test measurements on packaging material compatibility with emulsion films and follow up of BAM proposed designs