1. TRD Gas System Layouts Production Readiness Review 03 – Nov - 2003 F. Hahn

2. Content TRD Gas System: parameters and module layouts. TRD Distribution and Pressure Regulation Special Technology: channel flow meter Materials List Components: selection, cleaning, procurement. Deliverables from TA1 Cost and Schedule

3. Overview (Layout not TRD specific)

4. TRD Gas System Main Parameters (very expensive gas mixture) Gas mixture: Xe / CO 2 85% / 15% Total volume: 28 m 3 No. of Detector Modules 5 x 6 x 18 = 540 No. of Gas Channels Input: 3 x 18 = 54 Output: 14 No. of height Zones: 14 Hydrostatic Diff. (per height zone) 0.4 mbar Total Hydrostatic Diff. 2.6 mbar Total nom. circulation flow: 2.5 m 3 /h Max. circulation flow: 5 m 3 /h Nominal Gas Channel Flow: Input: 47 l/h Output: 140 - 425 l/h Nominal replenishing flow: 1 - 10 l/h Chamber pressure 0.5 - 1.0 mbar Max. overpressure on the Module: 3 mbar (Impurity Limits: O2, N2 t.b.s.)

5. TRD Gas Circulation Loop (ALEPH cryogenic separator)

6. Mixer Module 2 Primary gases Mixture : Xe / CO 2 85% / 15% Fill and Run MFC for each gas

7. Purifier Module Twin column Purifier Module with inline regeneration.

8. Membrane Separator (Overview) (optional) Note: the module may have two or three membranes

9. Membrane Separator (Sub-Modules

10. Pump Module

11. Exhaust Module

12. On-Detector Equipment: Three modules together

13. TRD Distribution On the Plug

14. Distribution Sub-Unit Pressure controller Flow Cells measuring input flows Shut-Off Valves for Sub-unit Flow adjustment pre-defined by capillaries

15. PT100 Channel Flow Meter Flow Cell incorporated in input and output gas manifolds. Measurement Principle: 1)Measure ambient temperature. 2)Switch on heating current 3)Wait until T has risen by  T=20 o C. 4)Take last 50 points and fit slope. 5)Wait until cool down to ambient T. (~40 sec.) 123 4 5 Measurement cycle ~ 30 sec/channel Proposed by M. Bosteels Developed by: S. Haider, C. Zinoni + S. Morozov

16. Pipe Summary Preliminary: existing partially new Options: a)Capillary input lines start on the Plug -> Ø=4/6mm (requires new tubes) b)Plug -> UX is done with existing tubes. Capillaries start in UX (diameters much smaller). or bigger Pipe sizes and length must be checked and validated by TRD and TC.

17. Material List To be checked by TRD Group

18. Cleaning, Component Selection + Procurement Many tests done for component purity. Arrangements with suppliers for grease free components are put in place. Extra cleaning for some components is done at CERN. (depends on requirements, serious congestion in cleaning CERN service) Numerous compatibility tests for radiation and B-field compatibility. All electrical and electronic components are tested. Simplified purchasing procedures arranged by SPL with many suppliers.

19. Work share for TRD Gas System TA1 will cover the selection and procurement of components, construction and installation of the gas racks. Special items (cryogenic plant, on-detector equipment) and the commissioning will entail several phases, and needs participation from the TRD group. Deliverables from TA1: –Standard gas system modules: Mixer, Purifier, Membrane module, Circ. Rack, Pump, 2 Distribution racks and some (minimal) Analysis. –Control system for all modules, PLC’s, etc. (not the PC’s for the control room). –Documentation: schematics, technical descriptions, user instruction manuals, To be covered by ALICE TC or TRD Group: –Modifications to existing fixed piping network : SG to Plug and Plug to UX. –On-Chamber equipment (pressure measurement, protection + back-up) –Procurement and testing of membranes. –New gas piping for connections from Distribution Racks to Chambers. –Cabling between Zones: SG to Plug, Plug to UX, and any cables to the chambers.

20. Cost Estimate: Includes 10% contingency

21. Gas Construction Plan (as known today) TRD