1. (on behalf of BAM Committee)
BAM project
Status report
S. Buontempo
(on behalf of BAM Committee)
Status of BAM tender
The BAM structure section by sections
Comparison of baseline and alternative solutions
Still open points…
The BAM LNGS site preparation
Conclusions

2. Status of BAM Tender
BAM firm has been selected: administrative documentation has been submitted to INFN Direttivo of January
We have a valuable technical and economical offer both for vacuum and mechanical solutions
The tender has been officially closed by the end of January 2004 on the cheaper solution (mechanical) for administrative reasons: the vacuum packaging is considered as an “option” to be added in February-March 2004 at most.
In this scenario we have got one month delay in BAM official schedule.

3. BAM Structure : Sections
BAM structure can be schematized in the following flow chart:
Feeding Pb + Em.
Piling
Alternative (mechanical)
Baseline (vacuum)
Pile Wrapping
Pile Wrapping
(light tight)
ECC packaging
Spring Packaging
Vacuum Check
CS + Skate gluing
CS gluing
External wrapping

4. Possible BAM layouts (vacuum)
Lead palletting
Piling
Robot
Quality Check
CS + Skates gluing
ECC Packaging
Additional protection
Emulsion palletting

5. Feeding section Emulsion Lead
BAM
Feeding section
Emulsion
Lead
No main differences among different proposed solution
Lead: full automatic handling
Emulsion: manual unpacking
ALL firms require Emulsion delivery packaging in groups of 57 films to guarantee 1 pile containing only emulsions coming from the same pack

6. Piling section
Lead and emulsion handling under control using vacuum suckers.
Lead and emulsion positioning in pile: several technical solutions proposed to guarantee demanded alignment at 50 microns
To be tested and fine tuned during BAM construction: final lead and emulsion needed

7. Pile protection (vacuum solution)
In Piling section we add on top and bottom of the pile PE end caps
They will have groves to get additional fiducial volume up to 6 cm3 (needed to extend the vacuum lifetime).

8. Wrapping section (vacuum solution)
BAM
Wrapping section (vacuum solution)
Clamp
PE film
All firms consider as crucial steps:
pile pressing to minimize air residual in it
pile wrapping by PE film to secure rigidity
in further manipulations
PE film

9. ECC packaging (vacuum solution)
BAM
ECC packaging (vacuum solution)
Vacuum chamber
The selected firm proposes a custom solution for vacuum packaging (commercial flow pack ruled out)
To be tested and fine tuned during BAM construction (final components needed) :
film folding
film welding
He injection

10. ECC packaging (vacuum solution)
ECC guide
Welding system
ECC block system
Film Folding
baseline
proposed by firm
Welding and cutting system
ECC guide
Proposed film folding slightly different from the baseline option but with same number and position of film layers
Need of He injection at hPa for fast enough and reliable vacuum leakage rate measurements

11. Vacuum Check section (vacuum solution)
Fly roller
Vacuum pump
Vacuum chamber
ECC pushing system
ECC
He leakage rate measurement (fast and sensitive down to 10-9 hPa l/sec) at lower vacuum level: ECC packaging is under stress
Large scale leakages monitored with no ECC film inflating
Given the large buffer volume (by pile end-caps), 10-8 hPa l/sec threshold to guarantee 10 years brick lifetime AT BAM EXIT : No guarantee after aging and manipulation effects

12. CS and skate assembling section
(vacuum solution)
CS inlet
Cylinders
Brick
CS warehouse
Skates warehouse
Brick lift up cylinder
Film folding, CS and skates demands for glue dispensers in the BAM clean room

13. Light tight wrapping Section (Mechanical solution)
Pile will start and finish with black PE protection layer
Pile additional wrapping using Al adhesive tape (low degassing) on top of PE thin film wrapping

14. Mechanical pressure given by springs
Springs can easily give a pressure of ~ 60 kg on pile surface (~ 0.5 atm),
Higher pressure is given by the fiber glass wrapping tape (up to 2 atm)
Candidate materials (…long list) under evaluation:
Carbon fibers
H30 acetyl copolymer with 26% glass fibers
P20 polycarbonate with 20% glass fibers
Liquid crystal polymer (LCP)
Polyphenylen sulfide (PPS)
long-fiber-reinforced thermoplastic (LFT),
thermoplastic polyesters
NOTE: no direct contact with emulsion-Pb pile

15. Spring packaging (Mechanical solution)
Positioning of springs on wrapped pile
Pressing of springs and wrapping them with fiber glass adhesive tape

16. CS and skate assembling section (Mechanical solution)
CS directly positioned on spring wrapping tape (using adhesive tape)
No CSS is needed
No skate needed: teflon adhesive tape on bottom will replace it
No glue dispensers required in this section

17. Summary for vacuum solution (1)
Potential drawbacks of vacuum itself + He injection:
10 – 30 hPa starting pressure of ECC packaging in He atmosphere
40 hPa vapor tension of the water at 20-30oC (pile will go to that value and some water will come out from gelatin, changing gelatin porosity: is it dangerous on the long term?)
The ECC packaging is oxygen tight but not water tight
(water vapor permeability < 0.3 g/m2/24h)
The residual of lamination emulsion (99% water + 1% oil) will also
evaporate (chemical aggression? Need of lead cleaning?)
Test measurements have started at CERN on single pile components (lead and emulsion) with help of ETS Division (degassing and metallurgy group)

18. Summary for vacuum solution (2)
Weak points of vacuum ECC packaging:
PE welding lines, due to re-polymerization after melting in welding procedure
Mechanical pressure on the pile given by the vacuum: loss of vacuum
means loss of pressure on pile
Fragility under mechanical manipulations
Brick shape is not mechanically regular
For the vacuum case we have the guarantee of brick lifetime only at BAM exit:
no guarantee on ECC packaging aging
no guarantee on manipulation stresses effects
The lifetime is extended having important fiducial volume (~ 6 cm3) added inside the ECC and detection of leakage rate of 10-8 hPa l/s

19. Summary for mechanical solution (1)
Granted advantages:
Much simples lay-out, reduced number of sections, simpler equipments (no check and maintenance of welding stuff, vacuum equipment, He feeding etc.),
Reduced pile manipulation (just up to wrapping)
Brick lifetime is not in question
ECC is robust for mechanical manipulations
Brick shape is very regular: smooth calibration, better brick-to-brick coupling, and toward CS
BAM would be cheaper in this option (anyway within the budget as for the vacuum case)

20. Summary for mechanical solution (2)
Possible advantages:
Pile is at 1000 hPa: safer for degassing (?) and water drying (?) (under tests with EST Division at CERN)
About tightness:
Light tightness checked : OK
Water tightness as good as vacuum solution
Air tightness being evaluated, but less critical due to no Dp with external environment (do we really need it?)
Note: material in direct contact with emulsion is only PE like for the vacuum option

21. Still open points…. (1) Emulsion films
Emulsion shape:
- final size of emulsion films after refreshing procedure,
- tolerances on the emulsion cutting size,
- shape of emulsion (cut on the edge and little hole in the corner).
Emulsion delivery packaging:
- Size of carton paper boxes,
- number of laminate film vacuum packs in each box,
- number of emulsion films in each vacuum pack.
Emulsion labelling:
- bar codes to read and register in BAM database ?
- where they are ? Important effects on the emulsion BAM operator job
- what we have to record in the BAM database and what on the brick label?
We need at least final refreshed emulsion film samples for BAM

22. Still open points…. (2) CS We need at least 100 CS samples for BAM
CS shape:
- final shape and folding edges,
- folded edges glued on the sides,
- decision of positioning of emulsion film inside the CS envelope.
CS delivery packaging:
- Size of carton paper boxes,
- number of CS’s in each box,
- type of laminated film used for CS packaging: compatible with LNGS safety rules and relevant for choice of glue to be used to fix it on CSS
CS labelling:
- bar codes to read and register in BAM database ?
- where they are ? Important effects on the emulsion BAM operator job
- what we have to record on the BAM database and on the brick label?
- do we need for CS a different label from the ECC one ?
We need at least 100 CS samples for BAM

23. Still open points…. (3) CS & CSS handling during OPERA data taking
Any choice we do, it will have effects on the BAM tooling and glue time needed and on the final procedure to handle the CS
What do we want to be “easily removable” from the brick: the CS alone or CS+CSS? (there would be no CSS in the mechanical solution)
We physically remove it or we just cut CS envelope and take out the emulsion film? ... And then we remove the envelope from the CSS (in vacuum case)....
Remember that:
- whatever we glue, we want it to be stable for 10 years.....
- we do not want to stress the CS film
- the glue must be compatible with the rest of the brick (ECC in mechanical case or CSS in vacuum case)
- we need then to expose the ECC to cosmic or to glue a new CS on it (new label ?) (we re-use part of the BAM to do it ?)

24. Still open points…. (4) Skates
The choice of vacuum/mechanical solution will affect the need to study or not the skate final shape and its mass production.
In mechanical case we do not need skates but we will add a skating tape on the bottom of the brick
In vacuum case the skates will be glues on on brick side on the ECC and on the other brick side on the CS:
- if we use different laminated films for ECC and CS this will demand different glues,
- if we want to remove the CS we have not to glue the “CS skates” on the ECC base (we remove the skate too) or we do not glue the CS on the skate (we leave the skate on the ECC with a free slot for CS positioning)

25. The BAM LNGS site preparation
The so called “by pass” area devoted to BAM installation needs two main actions to become the BAM site:
- Civil engineer work (remove concrete structures, insulation, crane)
tender closed in Jan04,
work starting in February,
delivery in 45 working days,
- Infrastructures (air conditioning, electric, compressed air, Ethernet and safety networks)
tender to be closed in march04,
delivery by fall04

26. Conclusions (1)
We have selected a firm with valuable technical and economical offer both for vacuum and mechanical options
Both offers are in the expected budget and time schedule
The BAM option will affect:
the BAM layout and needed infrastructures in the LNGS site
the kind and costs for packaging material
the studies to pursue in following months

27. Conclusions (2)
We are signing the contract with the firm on the cheaper solution (mechanical) to let it start working on the feeding and piling section executive drawings and prototyping.
The Collaboration is requested to chose the solution to let
the firm finalize the full BAM executive project: any delay in the
decision will be a net delay of the project.
We need urgently material (emulsion film + CS) delivered in Europe for the BAM project: any delay in the delivery will be a net delay of the project.

30. Laminated film candidates
SIDEC film
(custom for OPERA)

31. (proposed by selected firm)
Laminated film candidates
Antilux film
(proposed by selected firm)