CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider1 14 October 2011 Status of the Composite Vacuum Chambers M. Gallilee, C. Garion, M. Malabaila, G. Schneider, S. Sgobba, M. Taborelli, R. Veness  Experimental Beam Pipes  Materials  Carbon Beam Pipe Production  Design Options and Status  Outlook

CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider2 14 October 2011 LHCb UX85/3

CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider3 14 October G. Schneider TE/VSC ATLAS

CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider4 14 October G. Schneider TE/VSC ALICE Central Beam Pipe Installation

CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider5 14 October G. Schneider TE/VSC CMS HF Pipe

CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider6 14 October G. Schneider TE/VSC CMS HF Pipe

CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider7 14 October 2011 Beam Pipe Functionality List  Vacuum Leak tightness (< mbar.l/s) Bakeable (> 200 °C, ideally 300 °C) Outgassing (< mbar.l/(s.cm 2 ) Beam-surface aspects (photon, electron and ion desorption yields)  Mechanically stable for all load conditions  Transparency to particles  Activation  Impedance  Assure long-life  Cost  Availability

CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider8 14 October 2011 Activation Courtesy R. Veness, V. Hedberg

CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider9 14 October 2011 And why not Beryllium?  Brittle  High cost (several Chf/m)  Toxic vapours when machined  Long deliveries  Limited number of suppliers

CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider10 14 October 2011 Material Options

CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider11 14 October 2011 Why do we want carbon material? MaterialYoungs modulus [GPa] Radiation Length [cm] (  Y-Modul)* Rad. Length [ 3  Pa*cm] Steel *10 4 Titanum *10 4 Aluminium *10 4 Carbon-Carbon60 to *10 4 (for 100 GPa) Carbon-Epoxi100 to *10 4 (for 200 GPa) Beryllium *10 4 Nothing better than Beryllium… … but carbon fibre composite is also attractive 3

CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider12 14 October 2011 Carbon Fibre Tube (1) Carbon fibres are about to 0.01 mm thick Several thousand fibres twisted together make a yarn Make a fabric out of the yarn Wind the fabric or yarn around a mandrol (tube) in any angle between 0° and 90°

CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider13 14 October 2011 Carbon Fibre Tube (2) Add filler material Epoxy Epoxy, tar, … Cure in an autoclave at 150 °C to 230 °C Cure at 2000 °C Carbon-Epoxy tube High Youngs modulus (200 GPa) Max. bakeout temperature 230 °C Outgassing not vacuum compatible Carbon-Carbon tube Good Young modulus (100 GPa) Max. bakeout temperature no issue Outgassing vacuum compatible

CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider14 14 October 2011 How to get a carbon beam pipe leak tight with high transparency?

CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider15 14 October 2011 History  Composite Tube developments at CERN in the 80’s  Carbon – Epoxi tube was installed in LEP experiment Total Thickness 1.24 mm Diameter 106 mm Internal aluminium liner of 0.1 mm  Enventually failed, since the aluminium delaminated from the carbon structure

CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider16 14 October 2011 Vacuum Barrier Inside  Glue aluminium liner to carbon composite tube Looking into companies interested in the supply Looking into options to increase the resin temperature stability. Current options are epoxy, polyimide, cyanite- ester  Quotation exists (QinetiQ) for vapour deposition on carbon composite samples to test leak tightness  Chemical Copper layer on carbon by electroplating  Test made: Not 100 % surface coverage due to « rough » surface of the windings. Corrosion due to plating bath coming out from the matrix after the coating

CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider17 14 October 2011 Vacuum Barrier Outside  Carbon Tube with Vacuum Barrier Outside Advantage: Air pressure will push the liner on the carbon Disadvantage: Carbon will be seen by the beam Liner Carbon Tube

CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider18 14 October 2011 Vacuum Barrier Outside

CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider19 14 October 2011 Vacuum Barrier Outside (1)  Status Outgassing tests were made on a SGL Carbon Sigrabond Tube of type 2001 G diameter 104/100 mm inside a 300 mm long Titanium Grade 2 tube 0.3 mm thick with Titanium 5 Conflat flanges. Result: The outgassing rate is about 1x10 E-12 mbar.l/(s.cm 2 ) Test temperature: 250 °C No leaks of the titanium conflat to stainless steel conflat found up to 250 °C

CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider20 14 October 2011 Vacuum Barrier Outside (2) Spectrum of carbon-carbon beam pipe in Ti-vacuum barrier after bakeout at 200 °C

CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider21 14 October 2011 Beam Impedance  Benoit Salvant BE/ABP is working on the subject. 5 micron of aluminium coating inside the carbon tube seems to be sufficient

CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider22 14 October 2011 Vacuum Barrier Material AluminiumTitanium Radiation Length8.9 cm 7.9 cm for cm Galvanic couplingCriticalNon-critical Maximum Temperature250 °C300 °C Young modulus70 GPa110 GPa Thermal expansion (Carbon = 0) 23 µm/(m.K)9 µm/mK  We go for aluminium in order assure maximum transparency

CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider23 14 October 2011 “Exotic Solutions”  Carbon fibre aluminium composite Exists, but only in small dimesions. Trying to find manufacturers  Honeycomb structure instead of carbon In principle the technology exists, but we need very thin aluminium foil on either side of the honeycomb and we have high temperatures

CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider24 14 October 2011 Next development steps  Check how the Carbon-Carbon Youngs modulus can be increased  Look for high temperature resins  NEG coating on carbon beam pipe  Increase length of test beam pipes to 2 m  Study how beam pipe length can be increased to 8 m  Procure if possible Carbon-Aluminium tube  Study honeycomb structure Support: 12 Students from Oxford University given 3rd year project to study alternatives to beryllium (M. Gallilee)

CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH Gerhard Schneider25 14 October 2011 Composite Chambers 5 Year Roadmap 0.3 m Alu outer vacuum barrier/Carbon-carbon with NEG 0.3 m Carbon-epoxy*/Alu liner (glued or deposited) 0.3 m Carbon-Al composite 2m test chamber #2 2m test chamber #1 Test chamber in SPS Mid * Or other high temperature polymer like polyimide, cyanate-ester…