Winter Technical Stop Hardware Commissioning Strategies and Challenges

1. Matteo solfaroliand Mirko Pojer Hardware commissioning during winter technical stop Acknowledgements: R. Schmidt, M. Zerlauth, H. Thiesen, N. Catalan, K. Foraz, R. Giachino

2. Cryo-intervention planning

3. Powering test planning 2 shifts 5/7 days for access Chamonix: No shifts (Access covered by TI?) 3 shifts 7/7 days DSO tests

4. General layout • PC condemnation • ElQA monitoring of multi-kA circuits and spool pieces • RRR measurements during warm-up/cool-down • ElQA after re-cooldown • PC de-condemnation • QPS-IST with selective quench heater firing (only where disconnected) • Powering tests (special tests on RB.A56 to validate simulations) • Heat runs and GPM test • Cycling, cycling, cycling….

5. Key-drivers for ElQA • It was decided to perform the electrical integrity validation only on high current circuits, despite the thermal excursions • The MSs and ITs will certainly go (far) above 80 K → full ElQA • MIC will be done on MSs and ITs • The ElQA team and equipment: • Equipment for testing up to 4 sectors in parallel • 5 teams available inside the ElQA team (2 teams per sector + 1 (per MIC) needed) –> up to 2 sectors in parallel

6. Powering test streamlining • Main focus on protection interlocks (QPS/EE, PIC, PC) --> Almost all tests to verify the correct operation of interlock loops will be performed • Reduced number of other tests, according to expert requirements • Heat run for all circuits will be performed (8hours) as last step

7. Powering procedures (MP3) • Optimization • Modularity to be applied to all kind of situations (full commissioning, technical stop, components replacement,…) • Example: Courtesy of N. Catalan

8. Circuit specificities and NCs • List of non-conformities and powering singularities • RQTD and RQTF validation time extended to 190ms, can it remain for 4TeV? • RQS validation time extended to 190ms, can it remain for 4 TeV? • Higher order correctors in triplet? for higher E, lower beta? • RU • RCBX, limited to 350A due to difficulties to make the interlock on the square sum operating, issue with dI/dt • RPMBA.UA83.RQT13.L8B1 • RPMBA.UA27.RQTL11.R2B1 • RQS.A45B1 and RQS.A45B2 have a high value • Large part of 600A circuits were commissioned to the value required for 5 TeV • A few circuits have some issues, and were operated at lower current • The IPQ and IPD circuits were limited to 3.5TeV because of the missing splice resistance measurements • RB.A81 dI/dt needs to be set correctly • RQ6 – RQ10.R6 parameters HW limit set differently • RCBYHS5.R8B1 has an issue and is limited to 20A • RQX.R1: QHPS voltage reduction and capacitance increase Re-visiting and taking a critical look (new current limits for 4/5 TeV operation)

9. Resources • 2-3 weeks with 24/7: can the experts operate like that? • EPC will provide full support • PIC will be on best effort (most is automated) • QPS will mainly be on extended working hours • MP3 on full time (to be confirmed) • OP is already organizing the shifts

10. What LMC has recently endorsed • Installation of the snubber-capacitors on DQS for the dipole circuits • Discussion ongoing about their connection (to be tested for one sector, to be decided for the others) • Experts says they are needed for 4 TeV operation • Not needed for the RQD/F Energy change and snubbers → extraction time to be increased to 68s (12.5 s for the RQs) • Upgrade of all IPQ’s and IPD’s for 10V input and 500 Hz PM acquisition frequency • Decommissioning of the existing main bus-bar protection systems and respective reconfiguration of the main circuit protection. • Various software upgrades for the DQGPU’s • RRR measurements Courtesy of K. Foraz

11. Safety-related aspects

12. AUG and transformers replacement AUG tests Point 1 :Sunday 19th December – No access from point 1 to mid-arcs Point 18: Wednesday 5th January – No access in PM18, UJ18 Point 2: Thursday 20th January  – No access from point 2 to mid-arcs Point 3: Wednesday 8th December – No access from point 3 to mid-arcs Point 4: Thursday 6th January – No access from point 3 to mid-arcs Point 5: Tuesday 4th January – No access from point 5 to mid-arcs Point 6: Monday 10th January – No access from point 6 to mid-arcs Point 7: Tuesday 11th January – No access from point 7 to mid-arcs Point 8: Monday 20th December – No access from point 8 to mid-arcs Stop of ventilation in the arcs (transformer exchange) Arc 34 and arc 45: From Monday 17th January to Friday 21st January Arc 56 and arc 67: From Tuesday 11th January to Friday 15st January

13. Work Acceptance Tool Virtually, no more need for access operators Courtesy of K. Foraz

14. Beyond HwC BIS RF LBDS MKI/injection/TLs Collimators BI instrumentation Controls DSO tests Machine check-out

15. Concluding remarks • Tough planning (profitezbien des vacances!) • HC team is working on all test-related aspects: • Powering test streamlining • Powering procedures (MP3) • NCs • Implications of energy increase • Almost regular meetings with experts • Safety aspects are being considered • WAT will keep people away from the access consoles  • Tracking of performed activity in the tunnel is the key for a fast restart • Machine check-out can start after the DSO tests