Download - Roman Pot Project

http://totem.web.cern.ch/Totem/

TOTEM Collaboration Meeting

19 September 2005M.Oriunno, CERN PH-TOT

Roman Pot Project

Design and integrationMarco Oriunno, CERN




Some facts….The mechanical prototype 2004 has proven to work well -> upgrade for LHC

• Integration of one horizontal pot

• Integration of one dedicated BPM

• Enlarged size of the pot

• Thin window with improved flatness (~ 50 microns)

• New concept for the integration of cables and cooling

• Choice of Motors - LHC graded

• Vacuum issues

• RF issues

• LHC Integration issues




Final design of the Roma pot Unit:

•Upgrade of the Prototype tested in the SPS in 2004

•Vertical and Horizontal units interconnected by a bellow

•Dedicated Beam Position Monitor integrated in the unit

•Pre-series production ready to start in Czech Republic

•First unit ready to be tested at CERN in January 2006

TOTEM Roman Pot

Final design for LHC

Prototype SPS 2004




Layout around IP5




Pot Design• Brazing of the thin window

• Two boxes ready at the end of September

• Vacuum test

• Metallurgical test0.5 mm

0.2 mm

Test Vacuum Chamber for the pot




BPM Button•Adapted design for TOTEM

•Price offer received from CERAMTEC (in negotiation)

• Possibility to exploit CERN technology

• Delivery in 10 weeks after the contract signature

RF test bench in production in Prague




Services

Enlarged pot size

Integration of a new volume for the services : “Champignon” concept




1. The advantages for TOTEM of a compensation system interconnected to the machine vacuum have been understood and studies (Vacuum Physics calculations) are expected to confirm such a feature.

2. The fragility of the window during the bakeout phase has been argued from FEM calculations -> The Roman Pot system will be designed to be bakeable; extensive bakeout test to be done on the pot prototypes in September. Alternatives: Full bakeout of the system or integration of a temporary protective refrigeration system on the window.

3. Other points :

• RP vacuum gauges read by the machine vacuum control

• 316LN for the BPM buttons (already ordered at CERN)

• VacuumPraha is recognized as a firm able to supply system for LHC applications (particular interest in their development of ion pump)

• Installation of RP is not on the critical path of the machine, more details after the consolidation of the LHC planning

Vacuum Design issues




RF Design issues

Detailed study done by M.Deile under the supervision of F.Caspers

• Measurements in the SPS test beam with H/E antennas

• Measurements in the lab with a network analyzer using a wire-beam

•Experience based on similar measurements done for other LHC equipment

Conclusions (see Mario’s talk at the 6th RPTB

• Tightness of Roman Pot for e.m. fields:E-field attenuation by the windows: ≥ 60 dB @ 40 MHzB-field attenuation by the windows: 50 - 60 dB @ 40 MHz• EMI in detector electronics still to be measured• Beam coupling impedance of RP without ferrites: ≤ 1200 Ω• Good improvement with ferrites (factor 1/5)• Ferrite geometry to be optimized




RP Station at 147 m

Additional Sector valves




Future plans

Pre-series of the vacuum chamber ready end of November :

Vacuum Characterization and measurement on the compensation system

Final test on the Full Pot prototype

Integration study on the detector assembly

Tunnel Integration & cabling