THE VACUUM BOX FOR COMPASS CRYOSTAT MUNICH 23/10/2007 G. GIRAUDO I.N.F.N. TORINO 1.MECHANICS – OVERWIEV 2.WINDOWS 3.INTEGRATION WITH HODOSCOPE.

THE VACUUM BOX FOR COMPASS

CRYOSTAT

MUNICH 23/10/2007 G. GIRAUDO I.N.F.N. TORINO

1. MECHANICS – OVERWIEV2. WINDOWS3. INTEGRATION WITH HODOSCOPE

MUNICH 23/10/2007 G. GIRAUDO I.N.F.N. TORINO

MECHANICS - OVERWIEV

MUNICH 23/10/2007 G. GIRAUDO I.N.F.N. TORINO

MECHANICS - OVERWIEV

The First Cone holds the first detectors support, is made out of aluminium alloy and contains the gaskets (O-ring) housing. Mass 1.8 kg

The intermediate cone holds the connectors flanges, is made out of aluminium alloy. Mass 7.24 kg.

MUNICH 23/10/2007 G. GIRAUDO I.N.F.N. TORINO

MECHANICS - OVERWIEV

The final cone holds the second detectors support, the vacuum pipes-flanges and the suspension wings.All parts are made out of stainless steel (AISI 304)Due to the dimensions, two special gaskets should be made.Mass 10 kg.

Total mass of vacuum box = 21 - 22 kg

MUNICH 23/10/2007 G. GIRAUDO I.N.F.N. TORINO

WINDOWS

Four type of window was made and tested. Two of them fail when stressed by the vacuum after few seconds.One was able to withstand the stress due to vacuum, but shows a permanents deformation after few cycles and a big displacement in the centre (~30 mm)One was able to withstand the stress due to vacuum, but requires a bigger amount of material budget.

MUNICH 23/10/2007 G. GIRAUDO I.N.F.N. TORINO

WINDOWS

FAILURE: window was a sandwich of mylar foil (250 μm) carbon fibre (250 μm), glued on the flange with epoxy resins.Failure was due to the constraint, too flexible.

MUNICH 23/10/2007 G. GIRAUDO I.N.F.N. TORINO

WINDOWS

FAILURE: window was a mylar foil (250 μm) glued on the flange with epoxy resins, reinforced with 4+4 carbon wires.Failure was due to the constraint, the supporting surface is too small (wall thickness is only 9 mm), no FEM simulation.

MUNICH 23/10/2007 G. GIRAUDO I.N.F.N. TORINO

WINDOWS

NO FAILURE: window was a mylar foil (250 μm) glued on the flange with epoxy resins. Permanent deformation appear after few cycles, displacement in centre ~ 30mm - FEM simulation shows 12 mm.

MUNICH 23/10/2007 G. GIRAUDO I.N.F.N. TORINO

WINDOWS

NO FAILURE: window was a sandwich of mylar foil (250 μm), one ply of carbon fibre (125 μm), one layer of rohacell (5 mm), one ply of carbon fibre (125 μm) glued on the flange with epoxy resins. Good behavior under vacuum stress, good vacuum tightness. Simulation show a displacement in the centre of 2.3 mm, while measurement shows a displacement of 3.3 mm. Too much material.

MUNICH 23/10/2007 G. GIRAUDO I.N.F.N. TORINO

WINDOWS

NEXT: A new type of window is under study. The constraint wall is 15 mm, the window is now a foil of mylar (125 μm) glue on a support of high modulus carbon fibre ply (M46J - 200μ). Delivery this week.The foil is pinched between the flange and the cone wall.

MUNICH 23/10/2007 G. GIRAUDO I.N.F.N. TORINO

INTEGRATION