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CMS Gas Systems

(Nitrogen, Argon & CO2)

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Overview

• Different types• Uses• Layout of individual systems• Consumption figures so far• Operational troubling shooting• Final Comments

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Different types• Experimental gases

– Experimental gases required for specific experiments.• Experimental primary gases

– Nitrogen– Argon– CO2

• Flushing gases (Permanent inertion)– Nitrogen

• Fire Suppression gases (Temporary inertion)– Nitrogen

• Compressed air system– Nothing to do with this group!!!!!!!!

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Experimental gases

• SF6, CF4, C2H2F4, Ar/H2 & I-C4H10• These gases are used by RPC, CSC, DT

and TOTEM.• Supplied from the SGX5 gas building.

– Via the USC55 gas room into the UXC55 cavern

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Experimental Primary gases• Argon, CO2 & Nitrogen.• To be used by the detectors groups for use

directly related to the operation of the detectors themselves and operation of control racks.– Eg, Argon is used as part of the mixture of the CSC

system– Eg, Nitrogen is used to operate pneumatic valves

within the control racks.• Supplied from the SGX5 building.• Stored in bottles, batteries (Argon has a dewar)• This system is controlled and operated by

TS/LEA

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Primary gas layout

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Current Consumption figures(2007)

0 50000 100000 150000 200000

LAR(m3)

CO2(kg)

Argon(m3)

CF4(kg)

R134A(kg)

SF6(kg)

Helium(m3)

Azote(m3)

C2H6(kg)

Ic4h10(kg)

CH4(m3)

Neon(m3)

mixte

AR/H2(m3)

Xenon(L)

AR/CO2(m3)

Ln2(litres)

LCO2(kg)

Gas

Amount (in CHF)

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Flushing gases(permanent inertion)

• Nitrogen.• Used by several experiments to flush areas

between detectors to insure an inert,dry and helium free atmosphere is maintained.– Eg, Tracker.

• Supplied from a 50m3 dewar located just outside SDX5.

• The Dewar is controlled and operated by AT.• This system is controlled and operated by CMS.

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Flushing gas layout

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Fire Suppression gases(Temporary inertion)

• Nitrogen.• Used only in the event of a fire being

detected inside the detector.• Supplied from 2 tanks located just outside

the SGX5 building.• This system is controlled and operated by

PH.

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Fire Suppression layout

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Operational troubling shooting

• No piquet is forseen from TS/LEA• Who to contact?

– TS/LEA – Mats Wilhelmsson– CMS –Christoph Schäfer/ Gerd Fetchenhauer– AT – Goran Perinic– PH – Stefan Haider / Mar Capeans

• Possible failure areas?– Unreported increases in consumption

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Final comments• The 3 Nitrogen systems are completely

separate.• They are supplied from different sources• Different people are responsible for different

systems• DO NOT “MIX & MATCH!!!!!”• If the experimental Nitrogen system fails, then all

of the detector control racks will stop working!!!• Before using any of these systems, make sure

you inform the correct operator of your estimated consumption and flow rate figures.