(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

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.

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

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

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

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

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).

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

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

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 10-30 hPa for fast enough and reliable vacuum leakage rate measurements

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

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

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

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

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

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

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)

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

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)

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

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 10000 final refreshed emulsion film samples for BAM

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

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 ?)

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)

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

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

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.

Laminated film candidates SIDEC film (custom for OPERA)

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