Update on the thin RICH beam pipe project

Update on thethin RICH beam pipe project Fulvio Tessarotto - tests on prototypes - pipe production by Lamina - gluing exercises - time schedule - conclusions Fulvio TESSAROTTO

Activity on prototypes • We received from Lamina 4 “non aluminized” pipe pieces: • diam. = 100 mm, L = 1.3 m, tot. thickness ~ 180 μm • 4 layers of 36 μm thick Mylar wound and glued with S100 bonding agent • One was cut to measure the material properties and perform gluing tests • inner diam. = 100.1 +- 0.1, good compatibility with Araldite 2011, … • The second one has been equipped with aluminum end-cups to perform: • pressure tests (cylinder only for overpressure > 6 mbar) • deformation tests • He leak tests • Progress was possible because we solved problems of: • location (we equipped a room dedicated to these tests in Trieste) • technical manpower (two technicians are now helping on this project) • budget (INFN accepted to support the new RICH pipe) Fulvio TESSAROTTO

The prototypes without Al coating Fulvio TESSAROTTO

The Al flanges for this test Fulvio TESSAROTTO

The gluing for this test Fulvio TESSAROTTO

The result Fulvio TESSAROTTO

The first He leak test Fulvio TESSAROTTO

Temperature and pressure recording Fulvio TESSAROTTO

Fulvio TESSAROTTO

Simple He leak measurement • Volume = 10 l, fluxed with He, overpressure = 10 mbar, input closed. • Internal overpressure monitored for several hours: • External pressure, tempereature, humidity recorded too. • The overpressure evolves with T and P • Once corrected for temperature and pressure the observed leak • is ~ 0.3 mbar/h or less. This corresponds to ~ 3 ml/h leak • PRELIMINARY CONCLUSION: MYLAR AND GLUE ARE VALIDATED • A stainless steel pipe with 240 mm radius and 2 m length, with • flanges and gas connections has been bought and will host the • higher accuracy He leak measurements and the other tests. Fulvio TESSAROTTO

From the datasheet of the DuPont Teijin Mylar polyester film (the measurements have been performed using a 25 μm thick Mylar foil) at 25 ºC and for 1 bar pressure difference, a 25 μm thick Mylar foil with a surface of 645 cm2 leaks “typically” 150 cc/day  1 m2 will leak ~0.1 l/h Our validation figure is 10 ml/h Which includes a safety factor of 4 with respect To the maximum allowed leak rate of 1l/day For the prototype which has a surface of 0.4 m2 and no coating we would expect a leak of ~ 40 ml/h divided by a “thickness factor” Fulvio TESSAROTTO

expected leak: tickness factor For water vapor, the increase from 25 μm to 144 μm of the mylar thickness corresponds to a decrease of a factor ~8 in the transmission rate If the factor is the same for He, we would expect ~ 5 ml/h leak. We see ~3 ml/h Fulvio TESSAROTTO

End-caps and gluing studies Fulvio TESSAROTTO

microflange Fulvio TESSAROTTO

production of the pipes by Lamina • The base material, coated by Sheldahl, has been checked by Lamina: • - measured thickness = 27 μm, • - surface resistivity = 0.5 Ω / □ • (The amount of material is sufficient for 10 pipes) • 4 pipes are being produced this week: • 100 mm diameter, 1800 mm long pipes • 4 layers of Mylar, 25 μm thick, with 200 nm Al coating • spiral winding and gluing via 5 μm thick cross-linking polyester • 2 pieces will have an extra layer of Mylar, 36 μm thick (no Al coating) • (total thickness ~170 μm) • 2 pieces without the 36 μm extra layer • (total thickness ~130 μm Mylar) Fulvio TESSAROTTO

The base material is the same as: Fulvio TESSAROTTO

Technical data Fulvio TESSAROTTO

Engineering drawings from Fulvio TESSAROTTO

Pictures of the pipe: Fulvio TESSAROTTO

Summary of default choices: Issue default choice Removal of presently used pipe Cutting and extracting it Material for the thin pipe 4 layer aluminized Mylar, < 0.8 ‰ X Geometry 2 pipes 100 mm diam, 1600 mm long Gas He, flowing at few l/h, 20 mbar overpr. • End caps PET or microflange: still to be defined Fixation system Rings + wires: still to be defined Fulvio TESSAROTTO

Time schedule Pipe prototype production and tests November RICH beam pipe production: December Validation tests: January Installation: February Contingency in case of problems: March RICH operation tests with new pipe Aprile Fulvio TESSAROTTO

Conclusions: The thin RICH pipe project is progressing, and problems about procurement, logistics, budget and manpower are being solved. The uncoated prototype allowed to test stiffness, gluing, He tightness. Technical solutions are being tested for end-caps and fixation system. Real RICH pipe prototypes are being produced. They will be tested in the incoming weeks. The present time schedule is compatible with installation in Feb. - March 2012 Fulvio TESSAROTTO

Material budget actual pipe material budget: (0.15 mm / 17.6 mm) 8.523 ‰ X0 goal for the material budget of the new pipe: 10% actual = 0.852 ‰ X0 4 layers of 25 μm thick Mylar : (0.1 mm / 287 mm) 0.348 ‰ X0 4 layers of 200 nm thick Al coating: (0.8 μm / 89 mm) 0.009 ‰ X0 1 layer of 36 μm thick Mylar: (36 μm / 287 mm) 0.125 ‰ X0 • 4 layers of 5 μm thick Mylar glue: (20 μm / 287 mm) 0.070 ‰ X0 ----------------------------------------------------------------------------------------------------------- estimated total material budget for orthogonal crossing: 0.552 ‰ X0 (with respect to the goal we have a margin of 50% with the present design) The contribution from end caps, fixation rings, gas connections will be relevant For a 5 mrad particle (thickness * 200)  0.110 X0 from the pipe, 5 x 2 mm thick nylon  (10 mm / 367 mm) = 0.027 X0 from the support rings Fulvio TESSAROTTO

We need Accurate description of the mechanical properties of the pipe Estimate of the mechanical stresses applied to the RICH pipe Preliminary definition of the support – fixation system Computing the stresses and the deformations of the pipe (help needed!) Define the acceptable figures for the deformations (are 2 mm o.k.?) Building a testing device for the validation of the prototypes To measure the effect and validate the prototypes and the fixation system scheme Fulvio TESSAROTTO

Update on the thin RICH beam pipe project