1. IBL cooling status Pixel week 15 October 2014 Bart Verlaat, Lukasz Zwalinski, Maciej Ostrega, Claudio Bortolin, Piotr Gach, Artur Szlachcic, Olivier Crespo Lopez, Carolina Deluca, George Glonti, Jan Godlewski 1

2. CO 2 cooling system status The cooling system is fully operational, ready for bake-out and detector cooling Lots of achievements since last pixel week in May. –Installation of flex lines –Connection of the detector –1 st cooling of the detector –Finalized cooling system control Control loops tuning Alarm handling Automatic procedures DCS & DSS interface Still work to do after bake-out –Flow tuning in detector to optimize performance –Make blue print scans of the system for future reference –Some issues to be solved at plant level (plant okay for operation) Insulation issues, we need dry-air flush Heater moisture problems Plant covers –Documentation and publication. –Upgrade of capacity The current tuned configuration is lacking cooling power at low temperature operation To be decided whether to do it in LS-1 or later (Cold operation needed after severe radiation) 2

3. Cooling plants in USA-15 3

4. Transfer line installed in October ‘13 CO 2 cooling hardware in UX Junction box installed in March‘14 Vacuum system installed in April‘14 Manifold box installed in June‘14 Flex lines installed in June‘14

5. Todays check-out by junction box -35’C cooling 20’C cooling Accumulator pressure lowering for cool down Pressure increase for liquefying Typical cool down (over junction box)

6. PLC and SCADA software completed SCADA already migrated to 3.11 LHC logging for A&B activated and tested LASER alarms to CCC fully operational and tested with TI operators DIP data to DCS are ready Direct Modbus communication DSS fully functional Access control ready (personal login) Swap procedures tested Few numbers: ~230k lines of PLC code 366 alarms and interlocks 81 user interface panels Control status

7. Flex lines routing from Manifold box to IBL 7 Manifold in Muon S5 Extra length storage

8. 25 June, 1 st CO 2 flow through the IBL 8 1 st cooling of the IBL detector Opening of Junction box valve, 1 st flow through IBL Flow tests Cooling stop, ambient heating 20’C set point => Liquid cooling Perfect flow match with SR1 data SR1 data Not able to cold due to absence of IDEP covers

9. Low temperature IBL cooling (after IDEP closure in August) Around 2 months of running over the detector up to now at several temperatures (Mostly -5’C) The cooling shows more temperature loss than expected between the junction box (controlled reference) and the detector. –About 3-5’C difference. –Not fully understood why it is different than lab-tests (ca 2’C expected). –Understanding the detector thermal performance is priority after bake-out Stave thermal performance is perfect. –3’C at 23 watt => TFoM=15K*cm 2 /W, as designed. Some boiling difficulties observed at higher temperatures –Initial higher temperatures at start, once boiling is triggered performance is okay. –Need better understanding to avoid temperature differences in IBL 9 Stave 01 example Heat load Cooling pipe inlet Cooling pipe outlet Module 1,2,6 & 8 Lowest recorded module temperature: -25’C at -35’C cooling

10. IBL CO 2 super heating 10 Temporary stop of flow Boiling triggered for some inlets Some inlet temperatures showed higher values, after a short flow stop they dropped to the same values as all the others: Boiling was triggered. The effect is known as liquid superheating, without distortion it can be liquid above the saturation temperature. A trigger makes it boil (Like a bubble chamber detector from the past). When boiling it in generally stays boiling. Example in stave 08 show non–boiling also at outlet level, boiling is triggered up stream Stave 08 Boiling starts (ca 5’C drop)

11. Bake-out preparation For bake-out the CO 2 cooling has a special operational mode. –2 systems run in parallel at -25’C SP, providing twice the flow. –If 1 plant fails, the other is sufficient to cool during bake-out Bake-out continues. –If both fails than an emergency blow system gets active 1 Battery (12 bottles) with 500kg CO2 is blown through the detector at nearly the same flow conditions as a single plant. Up to 3hours of additional cooling with 3kW capacity Bake-out is interlocked Tests have been carried out to prove concept –Blow system is fail safe as it starts automatically when everything fails –It runs also without power 11

12. IBL plant failure test with 3kW heat load The graph show a failure of plant B and A followed by the blow system activation. A 3kW heat load was on all at time. Shown are the flows and heater temperature. 12 Failure of plant B Plant A continues delivering flow Failure of plant A Blow system delivers identical flow as 1 plant Cooling temperature remains stable Heater temperature (With 3kW load) remains cooled during the failure mode test 25 minutes of stable 3kW cooling using blow system (3kW Test was stopped to save CO2)

13. 13 Cooling performed by cold liquid from the cooling plant Cooling performed by warm liquid from the battery Heated CO2 for proper venting Vented CO2 gas 2-phase CO2 in junction box provided either by plant or blow system Returned CO2 from transfer line Temperatures during inactivity are deleted IBL plant failure test with 3kW heat load The graph show the same test as the previous graph and displays the temperatures in the cooling plants and in the blow system

14. Blow system failure tests The graph shows the result of the failure test of the blow system heaters and water flow. A mix of gas and dry-ice is vented and is not causing flow clogging 14 Dry-ice venting Blow system heater and water failure Slow reduction of cooling temperature in junction box Bottle empty of liquid, continued cooling with gas 2-phase cooled junction box with gas provided from bottle

15. Blow system freeing during heating failure tests 15 Frozen water heat exchanger Frozen vent line, venting of dry-ice in ventilation shaft Pressure regulatorBack-pressure valve Artur studying the ice making process

16. 1 st October: Thermal chock incident During the final blow test through the detector, suddenly after the test was over and system was emptying a slug of liquid entered the warming up detector. –A thermal shock happened from 0 to -35’C within a minute. There was the fear of serious damage –But results so far show no damage fortunately. The case is studied severely to understand the cause and prevent it from happening ever again. –Previous signatures like the stave01 after chocks have been observed in small at previous system stops. Where does this come from? 16 Thermal chock Stave 8&10 not affected (Last in manifold) After chocks in stave 01

17. Understanding the cause It was discovered that the plant safety by-pass injects liquid from the closed off plant into the liquid line –A flow small continuous flow through the detector is present after stop – Vacuum insulated transfer line can house liquid for a long time like a dewar. –Liquid slugs get pushed into the IBL time to time –At a normal stop not so problematic, as pressure is also increasing –At blow incident the pressure was decreasing causing this effect to be large Also a larger pressure drop so more liquid from the expanding plant. Due to incident the previous not understood phenomena is now understood A safety by-pass at plant level connecting the liquid to the vapor line should solve this 17

18. nc PV112 PV312 Safety by-pass 2 Normally closed pneumatic valves will be installed (IBL A and B). Valves will be connector to current blow system connection Installation after the bake-out as safety by-pass is also by passing the blow flow when triggered. By-pass valves are warm and similar type as the service manifold

19. Safety by-pass stop test Plant B-valves were used to simulate a safety by-pass. No observation of entering liquid after stop By-pass will be installed after bake-out 19 Cooling pipe temperatures Stave 01 temperatures Manifold temperatures This looks like the same effect but is due to condensation inside the IBL staves as they are colder due to pixel cooling

20. Summary IBL cooling is fully operational IBL cooling is ready for bake-out (Starting tomorrow) More tests need to be performed –Understand pressure drop phenomena –Make blue print of system performance for future reference –Flow tuning of detector loops –Need dedicated time for cooling tests (over JB and detector) Some work still ongoing at the plants –Solve insulation issue –Solve heater issue –Install safety by-pass Need to write documentation and publications 20