May 2003 LNGS OPERA Collaboration Meeting Brick Alternative

May 2003, LNGS OPERA Collaboration Meeting Brick Alternative Layout S. Buontempo on behalf of BAM Committee • Present design (Baseline) and “minor modifications” • New CS and CSS design • Alternative folding solution (Baseline no T) • Alternative packaging (no Vacuum) • Proposed strategy 1

Present design (Baseline) ECC Carton paper CSS CS (one emulsion sheet covered by laminated paper) Pile (emulsion, lead, emulsion, …) Skates 2 Laminated paper (exploded view, not to scale)

Baseline with “minor modifications” ALL the pre-selected firms moved the following critics to the Baseline option: “The carton paper is not recommended because it could create severe problems to perform long term vacuum and its degassing (glue and carton) could be dangerous for emulsion film too” As alternative solution they propose either to substitute carton paper with PE or to perform pile wrapping with adhesive tape on pile thickness We replied that we (BAM Committee) will evaluate any alternative proposal and OPERA Collaboration will have to endorse it. The must is NOT to exceed brick dimensions according to official specs. 3

Present CS design Changeable sheet Thermal welding Emulsion sheet Put inside laminated paper envelope Max thickness Folded lateral parts Folded top part According to our Nagoya Colleagues, there is a difficulty in shaping the lower part of the CS laminated film 4

New CS design Changeable sheet Thermal welding Emulsion sheet Put inside 2 pieces of laminated paper Max thickness Folded lateral parts Folded top and bottom part The envelope is done starting from 2 independent pieces of laminated film welded on all 4 sides. 5

New CSS design A new CSS design should be done to hold the new CS packaging ECC Side view ECC CSS A B In case A the CSS will have a shape to hold the folded parts of the CS. This manufacturing had to be compatible with the compensation of different folded parts of the ECC according to the baseline option of BAM specs document. If the moulding of this kind of CSS will turn out to be impossible because of too thin layers we will move to Case B that will cause two zones of less guaranteed planarity of 6 CS.

Alternative Folding solution (Baseline no T) 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 solution (Baseline no T) Advantages: - no T point so less risk in leakage rate, - flat surfaces for CS+CSS positioning, simpler CSS, easier positioning, - thinner brick, so possibility to put 2 CS Beam view Disadvantages: - new dimensions (being checked) - folded parts on the bottom to be compensated by skates, - folded parts on the side to be compensated by skates, - not flat surface for BMS vacumm sucker 8 Beam See J. Dupraz talk for preliminary test measurements on dimension of the brick and on leakage rates.

Alternative Packaging solution (no Vacuum) Two of the pre-selected firms proposed a completely alternative solution for brick packaging. They start from the following assumption (confirmed by Nagoya colleagues): “The role of the vacuum is to apply pressure to the pile in order to avoid relative sliding of emulsion films. The laminated film guarantees also the hermeticity and light tightness of the packaging” The proposal is the following: • they perform a NOT VACUUM packaging able to guarantee hermeticity and light tightness, • on top of it they apply pressure in mechanical way. 9

Alternative Packaging solution (no Vacuum) 1 - pile 2 - mechanical spring 3 - mechanical support 4 - mechanical corner protections 5 - kapton adhesive tape 6 - light tight and hermetic adhesive tape 10

Alternative Packaging solution (no Vacuum) 11

Alternative Packaging solution (no Vacuum) 12

Alternative Packaging solution (no Vacuum) 13

Alternative Packaging solution (no Vacuum) 14

Alternative Packaging solution (no Vacuum) 1 15 3 2 4 5 6

Proposed strategy (1) The BAM Committee has evaluated the modifications and alternative layouts here presented and proposes to the OPERA Collaboration the following strategy: • request to approve the PE solution replacing the carton paper as new baseline, • request to endorse the new CS and CSS design, leaving the following sentence in the specs document: “INFN retains the possibility to change CS and CSS design” • concerning “baseline no T” option the BAM teams and the involved firms will evaluate the compatibility with baseline option in terms of: - brick dimension, - compatibility with BMS, - compatibility with wall. 16 If everything is fine the BAM Committee propose to consider this as new Baseline.

Proposed strategy (2) • concerning the “Alternative Layout”, the BAM teams and the involved firms will performs all requested tests in terms of: - compatibility with emulsion - brick dimension, - uniformity and amount of pressure on the pile We propose to accept from the firms also economical and technical proposals on these scenarios and endorse them in the OPERA Collaboration in October 03 (after approval from BAM Committee). We require the OPERA Board to endorse this strategy in the present Collaboration meeting as an addendum to the baseline, after discussion and/or modifications applied by the Collaboration. 17