1Fulvio TESSAROTTO

Update on the

thin RICH beam pipe project

- prototypes validation and pipe production

- microflanges and fixation system

- the intervention inside the RICH

- proposed schedule - mirror alignment measurement

COMPASS TB meeting, CERN, 02/02/2012

Fulvio Tessarotto

2Fulvio TESSAROTTO COMPASS TB meeting, CERN, 02/02/2012

Production of the thin tubes

- November 2011: production of “final size prototypes” from Lamina failed- they refused to deliver the tubes because of “bubble problems”- R&D at Lamina; modification in the production procedure introduced- shorter prototypes (L = 1m) produced and shipped to Trieste

- December 2011: test of the shorter prototypes with thick flanges- validation of the aluminized Mylar tubes ( leak ~ 1 ml/h )- decision on the final material and order to proceed to production

- January 2012: further improvement in the production procedure- 5 pipes produced and shipped to Trieste

3Fulvio TESSAROTTO COMPASS TB meeting, CERN, 02/02/2012

Aluminized Mylar tube winding

4Fulvio TESSAROTTO COMPASS TB meeting, CERN, 02/02/2012

Aluminized Mylar tube prototype

5Fulvio TESSAROTTO COMPASS TB meeting, CERN, 02/02/2012

Aluminized Mylar tube prototype

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evolution from thick flanges

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to microflanges (first types)

8Fulvio TESSAROTTO COMPASS TB meeting, CERN, 10/11/2011

microflange: validated type

9Fulvio TESSAROTTO COMPASS TB meeting, CERN, 02/02/2012

Aluminized mylar tube prototype

CAD Drawingmachined piece

10Fulvio TESSAROTTO COMPASS TB meeting, CERN, 02/02/2012

stress and deformation studies

with 50 N: maximal deformation = 38 μm

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stress and deformation studies

with 50 N:maximal stress = 16 N/mm2

(Al yeild strength = 185 N/mm2)

by D. Scibetta

12Fulvio TESSAROTTO COMPASS TB meeting, CERN, 02/02/2012

Validation of microflange glueing

Complete prototype

glued Al pipe

13Fulvio TESSAROTTO COMPASS TB meeting, CERN, 02/02/2012

He leak measurement on prototypes

- Prototype with multilayer aluminized Mylar and microflange- Volume = 8 l, fluxed with He, overpressure = 40 mbar - Internal overpressure monitored for one week- Measurement inside a thermal isolation box- External pressure, temperature, humidity recorded- Corrections computed for temperature, pressure and volume changes

measured leak: 0.3 ml/h

ALUMINIZED MYLAR AND GLUED MICROFLAGES ARE VALIDATED

14Fulvio TESSAROTTO COMPASS TB meeting, CERN, 10/11/2011

The inox “Test chamber”

This stainless steel pipe with 240 mm inner radius and 2 m length hosts the He leak measurements based on differential pressure.

An MKS BARATRON Type 226 A provides 0.3 % resolution (50 mbar max) on the differential pressure (leak independent on T and p at first order).

15Fulvio TESSAROTTO COMPASS TB meeting, CERN, 02/02/2012

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

5 layers of 27 μm thick Mylar : (0.135 mm / 287 mm) 0.470 ‰ X0

5 layers of 200 nm thick Al coating: (1.0 μm / 89 mm) 0.011 ‰ X0

4 layers of 6 μm thick Mylar glue: (24 μm / 280 mm) 0.086 ‰ X0

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total material budget for orthogonal crossing: 0.567 ‰ X0

total material budget for parallel crossing (r < 42 mm): 2.26 ‰ X0

parallel crossing (42 mm < r < 49 mm): 1.9 % X0

6 mrad particle crossing the pipe (actual value = 1.4 X0) 9 % X0

The contribution from end caps, fixation rings, gas connections will be minimized

16Fulvio TESSAROTTO COMPASS TB meeting, CERN, 02/02/2012

Recent progress in understanding:Issue status

Removal of presently used pipe Extremely difficult behind the mirrors

Material for the thin pipe 5 layer aluminized Mylar, 0.6 ‰ X

Geometry 2 pipes 100 mm diam., 1570 mm long

Gas He, few l/h, 15 mbar overpressure

End caps alum. Mylar glued on Al microflanges

Fixation system Thin stainless steel wire ropes

Extremely difficult behind the mirror wall:

still to be defined

17Fulvio TESSAROTTO COMPASS TB meeting, CERN, 02/02/2012

New pipe

18Fulvio TESSAROTTO COMPASS TB meeting, CERN, 02/02/2012

New pipes inside the RICH

19Fulvio TESSAROTTO COMPASS TB meeting, CERN, 02/02/2012

New pipes inside the RICH

20Fulvio TESSAROTTO COMPASS TB meeting, CERN, 02/02/2012

Difficult pipe fixation

21Fulvio TESSAROTTO COMPASS TB meeting, CERN, 02/02/2012

Stainless steel wire ropes

22Fulvio TESSAROTTO COMPASS TB meeting, CERN, 02/02/2012

Microwire ropes

solution under investigation

23Fulvio TESSAROTTO COMPASS TB meeting, CERN, 02/02/2012

Proposed time schedule

RICH opening February 17

Scaffolding mounted February 24

Old pipe measurement March 2

Removal of the old pipe March 8

Mirror measurement March 16

Installation of the thin pipes March 29

Scaffolding dismounted April 13

RICH closing April 17

People directly involved: Didier Piedigrossi (LHCb)

V. Anosov, D. Cotte, G. Mallot, J.C. Gayde (+ A.B.,D.M.,M.B.,G.C.,E.L.,P.A.),

F. Tessarotto, S. Levorato, G. Menon, A. Kosoveu, L.Rinaldi, M. Gregori,

A.Zanetti, C. Azzan, D. Iugovaz, F. Borotto, M. Marengo, L. Steiger, M. Sulc.

M. Alexeev, …

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Jura bottom

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Saleve bottom

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Saleve top

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Jura top

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Photogrammetry targets (PTs)

There are important for precious determination of all four camera projection - principal points for CLAM

We have 5-6 PTs for quadrant but they are placed in on plane, so the positions are not independent

At least two new PTs (for each four quadrants) must be placed inside the RICH vessel to increase accuracy of absolute measurement

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Sketch of Photogrammetry targets positions inside RICH – today’s

situation

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Towards absolute

measurement…

Where to put additional optical targets?