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Cycle at 4 TeV and 7 TeV

Cycle at 4 TeV and 7 TeV. Many thanks to: the OP team ( S.Redaelli and W.Venturini included!), the optic team and the FIDEL team. outline. Commissioning. Cycle – operation. Cycle @~7 TeV. Conclusions. Commissioning (milestones). Commissioning (milestones).

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Cycle at 4 TeV and 7 TeV

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  1. Cycle at 4 TeV and 7 TeV Many thanks to: the OP team (S.Redaelli and W.Venturini included!), the optic team and the FIDEL team

  2. outline Commissioning Cycle – operation Cycle @~7 TeV Conclusions

  3. Commissioning (milestones)

  4. Commissioning (milestones)

  5. Commissioning (planning) J.Wenninger @LBOC on 21st Feb We are very good at planning!!!

  6. 2012 changes • Rampat 4 TeV • B3 decaycompensationatflatopseparatedfromtheramp • Squeezeto 0.6m β* • Further optimizationofopticsdistribution in thesqueeze • TiltedLHCbcollisions

  7. Commissioning (ramp) First ramp @4TeV after 2 days (beam 2 dumped after a few minutes at flat top due to a glitch in the safe beam flag) More ramps for tune, orbit and chroma measurements for feed-forward Most changes around 1 TeV, as in 2011 ORBIT: RT corrections applied (in few steps) TUNES: RT corrections applied in few steps (FF removed a tune bump between 100 and 200 s) Snapbackcorrection stillnot perfect(there are still tune correction spikes), to beanalysedduringLS1

  8. Commissioning (squeeze) • In 2012, 2 major changes on the squeeze strategy: • K function smoothing to reduce orbit spikes of 0.1 mm r.m.s, localized near the matched pointsand reproducible from fill to fill • The matched point distribution was improved by eliminating some points above 1.5 m and by allowing different β* values in the IPs ~120 mm J.Wenninger S. Redaelli

  9. Commissioning (optics) Optics measurements and corrections @4 TeV Around 20% peak beta-beating at flatop (very similar to 3.5 TeV machine) Beta beat at 0.6 m reducedfrom 90/100% to 7% in both beams

  10. Commissioning(collisions) V plane 100s 40s 220s 40s H plane 220s 100s Separation bumps Xing bump IR8: from H to V Xing Before FF Before FF 100 mm 100 mm After FF After FF 100 mm 100 mm

  11. outline Commissioning Cycle – operation Cycle @~7 TeV Conclusions

  12. Cycle @4 TeV FLATOP Current (A) RAMPDOWN SETUP SQUEEZE ADJUST RAMP PREPARE RAMP INJECTION PROBE INJECTION PHYSICS STABLE BEAMS… RB.A12 RQ6.L1 Time

  13. Analysis method • Homogeneoussetoffills(onlyphysicsfillswith 1092/1380 bunches, 0.6m β* in IP1/5) • ‘Rampdown’ & ‘setup’ not takenintoaccount • Time calculationfor beam modes(tools: logging DB, PM, logbook) This analysis is not meant to evaluate the efficiency of the machine but rather the performance of operation in the hypothetical case of 100% availability

  14. INJECTION WHAT WE DO • Inject the pilots and set up the beams • Fill the machine • Remove the injprotection COLL • Close the injection handshake

  15. PREPARE RAMP WHAT WE DO • Set up and switch ON the fbs • Settings incorporation • FGC+COLL functions load

  16. RAMP WHAT WE DO • Ramp • Incorporation (in the shade)

  17. FLATOP WHAT WE DO • Tunes check (RQTD/F currents) • Settings incorporation • FGC+COLL functions load

  18. SQUEEZE WHAT WE DO • Squeeze • Orbit fb OFF

  19. ADJUST WHAT WE DO • Bring the beams into collisions (LHCb tilting) • IPs optimization (sometimes)

  20. Cycle @4 TeV 36 min Unless differently specified, values are in seconds * length of the BP removed

  21. outline Commissioning Cycle – operation Cycle @~7 TeV Conclusions

  22. Cycle @(~)7 TeV • Operational cycle at 6.5 TeV • Injection at 11 m • Ramp to 6.5 TeV(1250 s) • Squeeze to 40/45 cm β* (1473 s –calculated for 55 cm) • Collisions (270 s tilting LHCb) • itshouldbe possible to go without the tilting if we have vertical crossing all along • Rampdown(~4200 s)

  23. Cycle @(~)7 TeV 51 min Unless differently specified, values are in seconds *calculated by adding replacing the estimated 2015 BP length to the 2012 values

  24. Cycle @(~)7 TeV • We have many possibility: • some of them would make the cycle shorter: • Ramp & Squeeze • Beta* levelling • Low beta (5/7 m) injection (90 m for highbeta) • Some would have no effect on time • Colliding & squeezing • ATS vs standard optic • Flat beams • 25 ns

  25. Cycle @(~)7 TeV MOST AGGRESSIVE SCENARIO: • Injection at 5 m (with collision tunes) • Ramp & Squeeze to 6.5 TeV / 1 m (1250 s) • Collisions without LHCb tilting (~100 s) • Beta* levelling from 1 m

  26. Cycle @(~)7 TeV 29 min Unless differently specified, values are in seconds

  27. Cycle @(~)7 TeV Thanks to FIDEL team

  28. Cycle @(~)7 TeV Thanks to FIDEL team

  29. Conclusions • 2012 commissioning was successful (first SB in 22 days!) – the machine was very similar to 2011 • On OP point of view we are approaching the limit time given by the settings, but we still can improve(flatop, rampdown,…) • Operation in 2012 was efficient and reproducible - despite the longer settings, the cycle was in average 36 min faster than in 2011 (big gain at injection) • The OP cycle at 6.5 TeV would take ~51 min (37%) more time than at 4 TeV • This can be reduced (up to ~29 min - 15%) • In order to properly prepare the 2015 operation we should converge on a possible scenario by mid 2013 • As baseline we propose to start with the same (type of) cycle as 4 TeV (well known!), then have a stop point around mid 2015 to steer the strategy

  30. SPARE SLIDES

  31. Commissioning(450 GeV) • Orbit of the flat machine was re-corrected, first against 2011 reference, then some absolute corrections were applied: • Orbit was found to be very similar to 2011 ref (0.2 - 0.3 mm rmsdifference) 0.47 mm 0.39 mm 0.36 mm 0.33 mm Optics measurements and corrections @450 GeV Beta-beating down to 5-10% from 30-40% Normalized H dispersion beat reduced from 0.04m1/2 to 0.01m1/2 B2 B1

  32. Commissioning (optics) Optics measurements and corrections @450 GeV Beta-beating down to 5-10% from 30-40% Normalized H dispersion beat reduced from 0.04m1/2 to 0.01m1/2 B1 B2

  33. SB & turnaround MEAN = 6 h 34 min MINIMUM = 2 h 8 min 24 s

  34. Commissioning (squeeze) Fill 2306 (Nov 2011) - r.m.swrt first orbit (arc) Ex: B1 50 mm ~120 mm With parabolic round-off 100 mm Fill 2534 50 mm After feed-forward The optimization can be further improved during LS1 to get less transient orbit spikes

  35. Cycle at 4 TeV Thanks to FIDEL team

  36. Commissioning (problems) • Glitch on the safe beam flag (noise on BCT2B giving values above the safe beam limit) • Intermittent interlock on BMPSA.4R6.B2 • Vacuum gauge outgassing between Q6 and Q5.L5 • Issue with generation of the functions for trim quadrupoles (some points were too close after incorporation) • Problem with the bunch placement on the MKI waveform • FGC: • A bug was found in the FCG software that ignored the real-time correction • Tweak on the current reference that was following the measured current

  37. Rampdown RQX.R5 W.Venturini RQD.A56 RQ4.R2 4min max

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