1. 1 25.03.2014 NSW/MM Layout & Design Working Group GAS DISTRIBUTION SYSTEM & FLOW STUDIES OF MM-NSW T. Alexopoulos, S. Maltezos, S. Karentzos T. Alexopoulos, S. Maltezos, S. Karentzos National Technical University of Athens

2. 2 25.03.2014 NSW/MM Layout & Design Working Group Updated design and configuration of the gas distribution system Updated design and configuration of the gas distribution system Results from the simulation (“Pipe-Flow”) Results from the simulation (“Pipe-Flow”) Gas Flow Studies Gas Flow Studies Outline -- Updates

3. 3 25.03.2014 NSW/MM Layout & Design Working Group What is available for the gas system?  Total gas volume is 6 m 3 (Ar:CO2 93:7 at atm. pressure)  Flow rate (renewals): ≤ 10 volume changes a day (flow rate ~2500 l/h)  Existing CSC gas racks (Ar:CO2 80:20 at atm. pressure) with 16 channels/rack can be reused (1 rack/wheel)  Existing MDT gas racks (Ar:CO2 93:7 at 3 bar) with 17 channels/rack can be easily adapted to atm. pressure (1 rack/wheel) For each wheel: 16 sectors x 2 typeMM/sector x 2 MP/typeMM = 64 Multiplet (MM types: LM1&2 or SM1&2) we use 16 channels/wheel  A gas channel serves 4 MP or 2 wedges LM1 LM2 SM2 SM1 Total cost ~13 KCHF/year for r =10 volume_changes/day

4. 4 25.03.2014 NSW/MM Layout & Design Working Group LM1 LM2 wedge gas-inlet gas-outlet impedance Gas manifold multiplet LM1 LM2 impedance Gas manifold multiplet A gas channel Gas manifold d=10 mm d=12 mm

5. 5 25.03.2014 NSW/MM Layout & Design Working Group Individual flow rate in each type of MM Feasible to manipulate the flow rates in a controllable way Impedances MM detectors (LM 1 +LM 2, SM 1 +SM 2 ) Gas input Gas output Flow rate Q t Q i+1 QnQn QiQi ZiZi Z i+1 Z8Z8 Updated impedances In the case that we would like to accomplish individual flow rates among the MMs, according to their renewal rates, we have to solve analytically the piping network (the pressure – flow rate relation is, in principle, non-linear). Use “Pipe-Flow” simulation. One impedance will serve two multiplets (LM1+LM2 or SM1+SM2 inner or outer). We need 64 impedances in total of two different characteristic curves.

6. 6 25.03.2014 NSW/MM Layout & Design Working Group The inner LM1+LM2 multiplets is supplied by 4 channels (Ch. 1, 2, 3, 4) Gas distribution for LM1+LM2 Inner MP – “PipeFlow”

7. 7 25.03.2014 NSW/MM Layout & Design Working Group Simulation results: zoom at sectors 1 & 3

8. 8 25.03.2014 NSW/MM Layout & Design Working Group Gas distribution for SM1+SM2 Inner MP The inner SM1+SM2 multiplets is supplied by 4 channels (Ch. 5, 6, 7, 8)

9. 9 25.03.2014 NSW/MM Layout & Design Working Group Simulation results: zoom at sectors 2 & 4

10. 10 25.03.2014 NSW/MM Layout & Design Working Group Simulation results: Inlet / Outlet pressure

11. 11 25.03.2014 NSW/MM Layout & Design Working Group Simulation results: Gas flow variation MM DET.LM1+LM2SM1+SM2 FLOWQ(l/h) 125.0816.38 225.0916.39 324.8416.27 424.8316.26 524.9716.33 624.9816.33 725.3216.49 825.1216.40 MEAN25.0316.36 RMS0.160.08

12. 12 25.03.2014 NSW/MM Layout & Design Working Group 0.5mm 2mm Gas Flow in LM1, radially Geometry: d hole = 0.5mm, d bz = 5mm, d in = d out = 2mm. Buffer zone: 1. n hole (1) = 13 2. n hole (2) = 17 5mm 1 2 LM1

13. 13 25.03.2014 NSW/MM Layout & Design Working Group Simulationof gas flow in LM1 : total time=2000 s Air Ar:CO 2

14. 14 25.03.2014 NSW/MM Layout & Design Working Group Comparison ………………………………………………………………………………………………………………………… ……………………………………………………………… a. plus 2 “outboard”holes b. without the 2 “outboard” holes Air Ar:CO 2

15. 15 25.03.2014 NSW/MM Layout & Design Working Group LM1 side”wall” buffer zone Geometry : n holes = 12. Mixed diameters (Model E-like). OUTLE T INL ET 0.5 4x0.75 1x1.00 0.5

16. 16 25.03.2014 NSW/MM Layout & Design Working Group Plus center hole Air Ar:CO 2

17. 17 25.03.2014 NSW/MM Layout & Design Working Group LM1 and LM2 outlet Inlet d = 2mm d = 5mm 5mm 2mm 0.5mm Geometry: d hole = 0.5mm d bz = 5mm Buffer zone: 1. n hole = 13 2. n hole = 17 3. n hole = 17, dhole = 0.5mm, 7 central dhole = 1mm 4. n hole =15 1 2 3 4 LM2 LM1

18. 18 25.03.2014 NSW/MM Layout & Design Working Group LM1 and LM2 Air Ar:CO 2

19. 19 25.03.2014 NSW/MM Layout & Design Working Group The configuration in which the gas goes through multi-planes instead of single planes-layer has been studied and simulated by using the “Pipe Flow”. We assumed 16 gas channels per Wheel. The functional curves of the impedances have been updated. In this configuration we need 32 impedances per Wheel. From the simulation “Pipe-Flow” conclude that the gas flow through the multi-planes seem adequate uniform. Individual plane-layer gas flow simulation has been performed to study the uniformity of the gas flow. More work on model of gas diffusion through mesh is in progress… Summary & on going work