Update on the thin RICH beam pipe project

1Fulvio TESSAROTTO

Update on thethin RICH beam pipe project

- tests on prototypes

- pipe production by Lamina

- gluing exercises

- time schedule - conclusions

COMPASS TB meeting, CERN, 10/11/2011

Fulvio Tessarotto

2Fulvio TESSAROTTO COMPASS TB meeting, CERN, 10/11/2011

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)


The prototypes without Al coating


The Al flanges for this test


The gluing for this test


The result


The first He leak test


Temperature and pressure recording



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, withflanges and gas connections has been bought and will host thehigher accuracy He leak measurements and the other tests.


at 25 ºC and for 1 bar pressure difference,a 25 μm thick Mylar foilwith a surface of 645 cm2

leaks “typically” 150 cc/day 1 m2 will leak ~0.1 l/h

From the datasheet of the DuPont Teijin Mylar polyester film

(the measurements have been performed using a 25 μm thick Mylar foil)

Our validation figure is 10 ml/h

Which includes a safety factor of 4 with respectTo 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”


For water vapor, the increase from 25 μmto 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

expected leak: tickness factor


End-caps and gluing studies


microflange


microflange

16Fulvio 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)


The base material is the same as:


Technical data


Engineering drawings from

Draw Code MIN MAX

I.D 99,7 100,30

W.T 0,100 0,130

O.L 1800,0 1810,0

Confidential Property of:

Lamina Dielectrics Ltd, Daux Rd, Billingshurst, RH14 9SJ

Tel: +44(0) 1403 783131Fax: +44(0) 1402 782237

Email: [email protected] CUSTOMER: INFNPROJECT: Drawn by: PMH 9.11.2011Approved by: DGMaterial:

Polyester non shrink film thickness 0.025 mm coated with 2,000 Angstroms of Al

All dimensions in mm:

Tolerances

Linear: Angular:

X +/- 0.5mm +/- 0.5 0

X.X +/- 0.1mm

X.XX +/- 0.05mm

Unless otherwise stated on drawing

DEBURR AND REMOVE ALL SHARP EDGES UNLESS STATED OTHERWISE

Notes: Bond agent S100. 4 Layers of film wound at half pitch all Aluminium surfaces to point to the inner bore of the tube

TITLE:

100 mm internal diameter detector Drawing No.: 51.962.01

Issue: 1Date: 3.10.2011


Pictures of the pipe:






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


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


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


Material budgetactual 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


We needAccurate 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

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Update on the thin RICH beam pipe project