Detailed information on the OT gas system can be found on EDMS:

• LHCb_OT_GAS_SYSTEM (EDMS 827973);
• Pre-Distribution OT Gas System (EDMS 675174);
• LHCb OT oxygen and humidity Analysis (EDMS 810138).

The schematics of the OT gas system can be found here.

The description of the OT gas system can be found here.


The design parameters for the gas system are

Gas mixture	Ar/CO2 70%/30%
Total volume	3,7m^3
Total nom. circulation flow	~ 3.2 m3/h
Max. circulation flow:	~ 5.0 m3/h
Nominal replenishing flow	~ 0.1 to 0.2 m3/h
Max. replenishing flow	0.8 m3/h
Chamber pressure	0.5 - 2.0 mbar
Hydrostatic Diff.	~ 0.5 mbar
Max. overpressure	5 mbar
No. of Channels	36
No. of Sub-Dis. Units	2
No. of UX Racks	2
Impurities	O2 < 100ppm; H2O < 100 ppm

The assignment between the channels of the distribution rack and the detector modules is given in here (doc) or here (pdf) .

A report on leak rate measurements for all channels on the C-side after installation of the C-frames in the experiment is given here (doc).

A history of the flushing of the detector can be found here (xls).

A collection of informations on the components used for the gas system is given here.