COMPASS

Properties Of The Gases

for the COMPASS detectors

Flammable gases in red. Please send corrections.

PURE GASES
general handling @ CERN
name chemical
composition 1) 		purity
[%] 		relative
density7) 		density
[kg/m3] 		unit of delivery price
[CHF/m3]
Azote N2 > 99.999 4) 0.97 1.25 GDS 2) ? 3)
Argon Ar 46 > 99.996 1.38 1.78 GDS 2) 1.50
Carbon Dioxide CO2 40 > 99.99 0.76 0.98 GDS 2) 1.72
Helium He ? 6) 0.14 0.176 GDS 2) 10.40
Neon Ne 45 > 99.995 0.69 0.888 50l bottle, 200bar, 9m3 114.47
Methane CH4 45 > 99.995 0.56 0.717 50l bottle, 175bar, 11.2m3 22.39
Ethane C2H4 24 > 99.4 0.99 1.282 50l bottle, 15kg,
ca. 33bar, 11.7m3 		13.82
Tetrafluormethane CF4 45 > 99.995 3.01 3.88 50l bottle, 32kg,
ca. 127bar, 8.6m3 		306.79
Perflourobutane C4F10 - 9.46 8) ~7500 9)


MIXTURES
general handling @ CERN
components 1) mixing ratio
[%] / [%] 		class 5) unit of delivery price
[CHF/m3]
Ar 46 / CO2 40 70 / 30 III 50l bottle, 4.8m3 61.67
Ar 48 / CF4 45 / CO2 48 74 / 20 / 6 II 50l bottle, 7.5m3 93.87

1): numbers (if given) reffers to the quality type of the gas
2): Gas Distribution & Supply (CERN EST/LEA)
3): cheaper than Ar; exact price not yet confirmed (billing included in price for maintenance & service of CERN gas distribution network)
4): measured by the RICH group: impurity of H2O < 1ppm => indicates quality type 50 or better
5): describes the precision of the mixture
6): worst quality availiable -> quality type 46 <=> 99.996% (according to Carbgas info sheet)
7): normalized to air: 1.29 kg/m3 (0o C = 273.15 K, 1 atm = 1.01325 bar)
8): in gaseous phase, 1.0 bar, 0o C (in liquid phase: 1237.21 @ 1.2 bar, 0o C)
9): at 20o C (~11800 CHF/m3 at 0o C), just for comparison; C4F10 is normally handled and sold in liquid phase: 112 CHF/kg

This page was last updated on June 17, 2002 by Eric Weise