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Experimental Sectors
Ray Veness / AT-VACWith many thanks to
G.Foffano + W.Cameron TS/MMEPatrick Lepeule / AT-VAC
LIUWG - 6 III 08 Experimental Sectors - R.Veness
Schematic Layout of Experimental Sectors
Experimental cavern
Detector
Experimental beampipesQ1 Q1
Sector Valve
VAX
Zone
TAS
Remote flange
The beamline equipment in this region is symmetric about the IP and identical in 1 and 5.
However:
-the detector shielding environment is different in ATLAS and CMS
- Additional equipment for pumping the sectors is installed on the left of both IPs
Experimental beampipes in 1 and 5 are also symmetric around the IP, but very different in design
LIUWG - 6 III 08 Experimental Sectors - R.Veness
Contents
o ATLAS Experimental beampipeso Current situationo Required changes for a triplet upgradeo Future plans from the experiments (as understood by me)
o CMS experimental beampipeso Current situationo Required changes for a triplet upgradeo Future plans from the experiments (as understood by me)
o 19m to 22.8m zoneo Current situationo Options
o Summary
LIUWG - 6 III 08 Experimental Sectors - R.Veness
ATLAS: Current Situation
IP
TAS
58mm ID 80mm ID 120mm ID
TAS
LIUWG - 6 III 08 Experimental Sectors - R.Veness
ATLAS VJ chamber
VJ is integrated with a contilevered support and the LUCID detector.
The chamber is 80/120mm ID, but the bellows module interfacing with TAS goes down to 34mm ID
LIUWG - 6 III 08 Experimental Sectors - R.Veness
ATLAS: Required Changes for the Triplet Upgrade
Bellows module with 34mm ID
Remote flange on the TAS – 34mm ID
LIUWG - 6 III 08 Experimental Sectors - R.Veness
ATLAS: Future Plans from the Experiment
o Consolidation of VA chamberso Replace both chambers with low-Z versions in ~2009/10
shutdowno The diameter of the chamber is unlikely to change
o New VI chamber for B-layer or pixel upgradeo A new (beryllium) central chamber is being considered, either
in conjunction with a new B-layer or pixelo The schedule is not yet clear, but unlikely to be before 2011/12o The diameter would be ‘as small as possible’
o New forward chambers for SLHCo The whole forward region (currently VT and VJ) would be
changed with a machine luminosity upgradeo Higher luminosity would require low-z materials and perhaps
larger diameter chambers
LIUWG - 6 III 08 Experimental Sectors - R.Veness
CMS: Current Situation
58mm ID
Variable diameter 58~320mm 55mm ID
80-100mm ID
LIUWG - 6 III 08 Experimental Sectors - R.Veness
CMS: Required Changes for the Triplet Upgrade
Changes required in this region
LIUWG - 6 III 08 Experimental Sectors - R.Veness
CMS: Required Changes for the Triplet Upgrade
The remote flange and bellows module have an aperture of 34mm
LIUWG - 6 III 08 Experimental Sectors - R.Veness
CMS: Plans from the Experiment
o ‘Post-TOTEM’ Replacement of CT2 chamber (?)o The CT2 chamber was reduced to 55mm to accommodate
the TOTEM T2 telescope.
o CMS have plans to increase this diameter when TOTEM is removed, but the schedule and replacement diameter is not know (by me)
o SLHC Upgradeo CMS also have plans to replace the inner tracker, and
probably also the central beryllium pipe for a smaller diameter in time for an LHC luminosity upgrade
o It is likely that forward chambers will also change at this time
LIUWG - 6 III 08 Experimental Sectors - R.Veness
Current 19-22.8m Region
ATLAS TAS are 20-30mm further away from the IP than nominal, due to the position of the ATLAS forward shielding
LIUWG - 6 III 08 Experimental Sectors - R.Veness
Current 19-22.8m Region: TAS Chamber
Current TAS chamber is 34 ID / 60 OD
LIUWG - 6 III 08 Experimental Sectors - R.Veness
19-22.8m Region: VAX Zone
o Valve and BPMSWo Both 63/60mm apertureo BPMSW is between 2 bellows to allow
independent alignment – supported from Q1
o The valve behind TAS is installed at the request of the experiments to allow replacement of BPM electrodes without full venting of experimental sectors
o VAX (Vacuum-assembly-experimental)o 63/60 mm apertureo Assembles pumps and gauges for the
experimental sectoro Connected to gas injection system for
pump-down and venting of sector on ‘-’ side
o Sector Valveo 63/60mm apertureo Separates cold triplet from warm
experimental sectoro Interlocked
LIUWG - 6 III 08 Experimental Sectors - R.Veness
19-22.8m Region: VAX Zone
Access is very limited, and the VAX zone will become significantly activated!
VAC need access for maintenance of equipment. Survey and Beam instrumentation will also need access.
LIUWG - 6 III 08 Experimental Sectors - R.Veness
19-22.8m Region: Options
o Replace the TAS chambero First mechanical analysis seems to confirm
that the TAS copper chamber could be re-made to 55ID/60OD – ie, in the same TAS body
o It may be necessary to change the alloy to OFS (copper-silver alloy) to maintain high temperature strength
o Replace warm bellows module between BPMSW and VAXo This module could potentially be reduced
from 200mm to 100mm long, allowing Q1 to advance 100mm towards the IP
o Assuming the ATLAS TAS can be re-positioned on nominal
o Assuming the access to the zone is not compromised
o Increase equipment diameter??o Will we need to increase the diameter from
60mm to reduce activation of these vacuum components?
LIUWG - 6 III 08 Experimental Sectors - R.Veness
Summaryo Increasing the TAS aperture would require:
o Re-design and replace TAS chambers (4)
o Re-design, re-qualify and replace Experimental remote flanges (4)
o Re-design and replace ATLAS pumping modules (2) and CMS 18.6m bellows modules (2)
o Depending on the level of activation, experimental forward chambers may have to be replaced, as it may not be ‘ALARA’ to work on them
o Do we also need to increase from the 60mm in the VAX zone to minimise activation?
o Advancing the Q1o On first inspection, 100mm can be gained on the warm bellows module in front of
VAX
o More than this would require removal of equipment
o Apertures in the experimental beampipeso CMS CT2 pipe has a 55mm aperture at ~15m from the IP
o ATLAS VT pipe has a 58mm aperture at ~10m from the IP
o Both ATLAS and CMS have plans to reduce the pipe diameter in the ±4m from the IP region. They are currently informed that this is limited by injection optics. We should inform them quickly if the triplet upgrade may have an impact