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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
6Fulvio TESSAROTTO COMPASS TB meeting, CERN, 02/02/2012
evolution from thick flanges
7Fulvio TESSAROTTO COMPASS TB meeting, CERN, 02/02/2012
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
11Fulvio TESSAROTTO COMPASS TB meeting, CERN, 02/02/2012
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
-----------------------------------------------------------------------------------------------------------
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, …
24
Jura bottom
25
Saleve bottom
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Saleve top
27
Jura top
28
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
29
Sketch of Photogrammetry targets positions inside RICH – today’s
situation
30
Towards absolute
measurement…
Where to put additional optical targets?
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