1. f Tevatron Operations Ron Moore DOE Tevatron Operations Review March 27, 2007 SC-1 Breakout

2. f 2007 DOE Tevatron Operations Review – R. Moore 2 Since the 2006 shutdown ended…  209 HEP stores ( give/take a few…not counting ones lost before HEP)  Record delivered lumi / week 24.4 → 44.9 pb -1  Record peak luminosity 180 → 292 10 30 cm -2 s -1  Record # pbars at start HEP ≈ 3072 10 9  Delivered > 1 fb -1 to CDF and D0  Run 2 total delivered now > 2.6 fb -1, recorded > 2.0 fb -1

3. f 2007 DOE Tevatron Operations Review – R. Moore 3 Run II Peak Luminosity

4. f 2007 DOE Tevatron Operations Review – R. Moore 4 2006 Tevatron Shutdown Tasks  Fixed known cold leaks in E2, A3, B4; replace failed dipole in F4  Replaced all ≈1200 LHe Kautzky valves  Cause of 2 magnet failures prior in Nov 06 and Feb 07  Completed reshimming on remaining 228 dipoles  Needed 3 shutdowns to do! Cryostat sagging – causing coupling  Unrolled quads in A3 (~10 mrad); unroll ~60 magnets with small rolls  Installed 2 new separators (B48, A17), replace 3 separators (A49)  Repaired TEL-1 and installed TEL-2  Pulled cables for new sextupole circuits (2 nd order chromaticity correction)  Completed IPM detector installation  Completed ring-wide hydrostatic level sensor installation  Many smaller tasks, lots of maintenance…  Smooth start-up after such a long shutdown  Run II upgrades effectively complete

5. f 2007 DOE Tevatron Operations Review – R. Moore 5 Highlights since 2006 Shutdown  More pbars to HEP  Thanks to Pbar Source and Recycler  More protons to HEP  Injecting more protons  Better lifetime @ 150 GeV from new helical orbit  Improved luminosity lifetime  Additional separators increase beam-beam separation  Commission TEL-2  Spare abort gap cleaner & demonstration of beam-beam compensation  Smooth orbits to desired HEP position every store  Improvement on orbit stabilization  Faster halo removal – save few minutes  Get to HEP sooner  Online luminosity fits and model comparison  New tools based on SDA/SuperTable data

6. f 2007 DOE Tevatron Operations Review – R. Moore 6 Injecting More Proton and Pbars 2006 shutdown

7. f 2007 DOE Tevatron Operations Review – R. Moore 7 Improved Proton Efficiency @ 150 GeV 2006 shutdown

8. f 2007 DOE Tevatron Operations Review – R. Moore 8 Improved Proton Efficiency vs Pbar Intensity  New injection helix increased separation between beams (Yu. Alexahin)

9. f 2007 DOE Tevatron Operations Review – R. Moore 9 FY07 Integrated Luminosity D32-5 failure feeder 46B fault E39/43 vacuum failure A18 vacuum leak

10. f 2007 DOE Tevatron Operations Review – R. Moore 10 Getting More Proton and Pbars to HEP 2006 shutdown

11. f 2007 DOE Tevatron Operations Review – R. Moore 11  Long-range beam-beam effects degrade lumi lifetime + integral  Nearest parasitic crossings (≈59 m from IPs) especially bad  Additional separators installed to allow increased separation  More separation  reduced beam-beam effects  ~20% increase @ upstream IP  Not as much @ downstream IP  Luminosity lifetime improved ~20% compared to pre-shutdown  Increased integrated luminosity per store (for similar luminosities and store lengths) Luminosity Lifetimes

12. f 2007 DOE Tevatron Operations Review – R. Moore 12 Comparing HEP Stores to Model without Beam-Beam  After shutdown, luminosity evolution agrees better to model without beam-beam effects  Most pbars lost during HEP are burned in luminosity  That’s good!  Protons suffer more from beam-beam effects  Especially with smaller pbars V. Lebedev

13. f 2007 DOE Tevatron Operations Review – R. Moore 13 Better Lifetime  More Delivered Luminosity Based on luminosity lifetime fits and adjusting to 24 hour store duration

14. f 2007 DOE Tevatron Operations Review – R. Moore 14 Bunch-by-Bunch Tune Shifts: Store 5245  Higher pbar intensities  proton/pbar head-on tune shifts ≈ equal!  Proton / pbar intensity ≈ 3, but proton/pbar emittance ≈ 3, too!  Consistent beam intensities store-to-store is helpful operationally  Otherwise, tune changes needed in advance to prevent lifetime problems  Pbar intensities vary more - lost stores, problems in upstream machines, etc.  Bunch leveling in Recycler also helpful for Tevatron and experiments  More uniform bunch dynamics, more uniform bunch-by-bunch luminosity

15. f 2007 DOE Tevatron Operations Review – R. Moore 15 Tune Footprint Currently operate between 7/12 and 3/5 for collisions Considering moving near ½ integer

16. f 2007 DOE Tevatron Operations Review – R. Moore 16 Beam Lifetimes  Pbar lifetime dominated by luminosity – good  Most protons lost in non-luminous processes – not so good Luminosity [μb -1 /s] Pbar Lifetime / Expected Lifetime from Luminosity Store 5245 Proton Lifetime / Expected Lifetime from Luminosity

17. f 2007 DOE Tevatron Operations Review – R. Moore 17 Smaller Pbar Emittance  Worse Proton Lifetime

18. f 2007 DOE Tevatron Operations Review – R. Moore 18 Schematic of Beam-Beam Force on Proton Bunch

19. f 2007 DOE Tevatron Operations Review – R. Moore 19 Example of Tight Tune Space for Protons Operator error – tune pushed too high Longitudinal shaving Store 5008 L = 207

20. f 2007 DOE Tevatron Operations Review – R. Moore 20 Store 5245 – Comparison to Model w/o Beam-Beam Initial Lumi = 286 μb -1 /s ~10% loss from beam-beam

21. f 2007 DOE Tevatron Operations Review – R. Moore 21 Reliability  Replaced all He Kautzky valve poppets in 2006 shutdown  Successfully tested higher bandwidth quench protection electronics (VFCs)  Implemented in 3 houses, gradually propagate to whole ring  Helps detect quench and pull abort in ≈350 μs (< 20 turns)  Migrated control applications from VMS to Linux  A BIG job requiring careful testing and implementation in operational environment  2 Tevatron failure-driven shutdowns since June 2006  Mouse-induced feeder glitch resulted in D3 dipole failure (Oct)  Failed O-ring caused loss of E3 cryo insulating vacuum (Nov)  New pbar cogging for ramp since early Jan 2007  Pbars were in the abort gap previously – quench if abort up ramp  Now clear abort gap should prevent needless quenches (OK in only “trial” so far)  Implement new BLM electronics to allow aborts on high beam losses  Current system too inflexible – BLM aborts masked out during HEP

22. f 2007 DOE Tevatron Operations Review – R. Moore 22 Tevatron Reliability

23. f 2007 DOE Tevatron Operations Review – R. Moore 23 Integrated Lumi and Store Hours per Week 5 store running average scaled to 1 week

24. f 2007 DOE Tevatron Operations Review – R. Moore 24 Looking Ahead  Implement 2 nd order chromaticity correct @ low β  Correct second-order chromaticity @ low β  better lifetime  Also required for possible new working point (near ½ integer)  Work with experiments in optimizing integrated vs peak luminosity  Multiple interactions cause difficulties for trigger and tracking  When is peak too high? Do we need higher intensities afforded by new working point?  Other minor improvements – they all add up!  Scrape (higher intensity) protons @ 150 GeV Remove beam that would be lost anyway on ramp and squeeze Get “brighter” protons to HEP  Investigating new cogging between pbar injections Reduce beam-beam effects by changing locations of long-range crossings Improve proton lifetime @ 150 GeV (bunch-dependent)  More reliable tune measurements New 1.7 GHz Schottky electronics designed by FNAL (LARP) for LHC (better dynamic range) New digital tune monitor to measure individual bunches (with tickling)  Better helices, improved transfer line matching, faster shot-setups, etc.

25. f 2007 DOE Tevatron Operations Review – R. Moore 25 New Sextupole Circuits  Move 22 elements from existing SF&SD circuits to 12 new circuits  Correct 2 nd order chromaticity in low-β lattice  Should reduce non-luminous proton losses  Operational with new power supplies since early February  Cables pulled during 2006 shutdown  Still configured as “normal” chromaticity sextupoles  Conducting proton-only studies to implement in final configuration  New circuits to run at zero current except @ low-β  Need short access to flip polarity of some elements when ready  Could be operational in ~1 month  Simulation results in Alex Valishev’s slides

26. f 2007 DOE Tevatron Operations Review – R. Moore 26 Luminosity Projections  Refer to slides in R. Dixon’s talk  Projections assume ≈100 store hrs/week on average  Takes into account possible unplanned downtime (failures)  Based on current pbar stacking rate, appear on track to deliver 5.5-6.5 fb -1 total  Likely need increased stacking rates to go higher  Approaching design 320 μb -1 /s peak luminosity  Consult with experiments if higher is OK for them  Goal is to maximize integrated luminosity on tape

27. f 2007 DOE Tevatron Operations Review – R. Moore 27 Integrated Luminosity Peak Pbar Stacking Rates We’re in this area now 2.6 fb -1 ≈ 22 mA/hr March ‘07

28. f 2007 DOE Tevatron Operations Review – R. Moore 28 One Example of Model Parameters  In general, weekly integrated luminosity ≈ independent of store length in 20-30 hr range → flexible running schemes  Pbar stacking rate important factor

29. f 2007 DOE Tevatron Operations Review – R. Moore 29 Summary  Tevatron delivering record peak and delivered luminosity  Great start-up following long 13-week shutdown  Higher beam intensities to HEP, improved lifetime  Protons suffering more from beam-beam effects  Operationally challenging to stay in desired tune space when pbar intensities vary from store-to-store  Implementing 2 nd order chromaticity compensation circuits  Should improve lifetimes in collisions  Prerequisite for investigating ½ integer working point  Maximize integrated luminosity to CDF and D0  On track for 5.5-6.5 fb -1 at current pbar stacking rates  Let’s find the Higgs!

30. f 2007 DOE Tevatron Operations Review – R. Moore 30 Backup Slides

31. f 2007 DOE Tevatron Operations Review – R. Moore 31 AcceleratorHighest Energy Cockroft Walton750 keV Linac400 Mev Booster8 GeV Main injector150 GeV TEVATRON980 GeV NuMI (120 GeV) MiniBoone (8 GeV) P1 Line A1 Line

32. f 2007 DOE Tevatron Operations Review – R. Moore 32 FY Integrated Luminosity

33. f 2007 DOE Tevatron Operations Review – R. Moore 33 FY07 Peak Luminosity

34. f 2007 DOE Tevatron Operations Review – R. Moore 34 FY05-FY07 Weekly Integrated Luminosity 5 store running average scaled to 1 week

35. f 2007 DOE Tevatron Operations Review – R. Moore 35 FY 2007 Average Store Hours per Week

36. f 2007 DOE Tevatron Operations Review – R. Moore 36 Machine Studies and Maintenance  Averaged ≈6.5 hrs / week since last shutdown  Does not include parasitic studies  Exploit natural breaks in machine operation  Lost stores, pbar stacks, etc.  Exploit end-of-store studies  Focus on specific, well-prepared studies  Be efficient, prevent unnecessary quenches/downtime  Start with proton-only stores before trying in HEP  If we really need study time to implement something new for HEP, will get the time  e.g., proton-only for commissioning new sextupole circuits

37. f 2007 DOE Tevatron Operations Review – R. Moore 37 Bunch-by-Bunch Proton Losses @ 150 GeV Lifetime of a proton bunch degrades when it has a parasitic crossing with pbar bunch near B13 Proton #1 [E9] Proton #19 [E9] Pbar Int. [E9] Pbar cog [bkts] Proton #22 [E9] Proton #34 [E9]

38. f 2007 DOE Tevatron Operations Review – R. Moore 38 New Injection Helix  Increased separation at “worst” parasitic crossing blue – old red – present Parasitic Crossing Number (from B0) Separation in σ

39. f 2007 DOE Tevatron Operations Review – R. Moore 39 New Collision Helix  After adding the A17H and B48V separators in 2006 shutdown blue – old red – present Distance from B0 [m] Separation in σ

40. f 2007 DOE Tevatron Operations Review – R. Moore 40 Better Lifetime  More Delivered Luminosity Based on luminosity lifetime fits and adjusting to 24 hour store duration

41. f 2007 DOE Tevatron Operations Review – R. Moore 41 Separation at IPs with different cogging at injection S 1min S 2min Injection cogging n cog =61 n cog - cogging w.r.t. the collision one, n cog =0 Measured helix and optics used, reference emittance 15  mm  mrad

42. f 2007 DOE Tevatron Operations Review – R. Moore 42 Beam-Beam Resonance Strengths vs Injection Cogging Nominal values @ injection n cog =61 (before change ) Collision cogging: n cog =0 n cog =-2 is the best for 7Qy n cog =10 is good for 5Qx while not bad for 7Qy 5Qx 7Qy n cog RDTs (Resonance Driving Terms) calculated for 3  amplitude Yuri Alexahin Now implemented for ramp

43. f 2007 DOE Tevatron Operations Review – R. Moore 43 Kautzky Valve Poppets  During quench, pressure forces valve open, allows He to escape  Poppet can break off, remain in closed position  1 similar failure in 20 years, then 2 in three months → Replaced all ≈1200 He Kautzky valve poppets during 2006 shutdown  No poppet failures since replacement Closed Kautzky valve Broken poppet from B17 spool Kautzky valve

44. f 2007 DOE Tevatron Operations Review – R. Moore 44 Online Luminosity Evolution Fits  Bunch-by-bunch lumi and beam intensities, too  Different fit functions and results stored in database, spreadsheets, etc.  Useful for Run Coordinator to determine end-of-store time

45. f 2007 DOE Tevatron Operations Review – R. Moore 45 D32-5 dipole beam tube Holes from arcing Flashover in Feeder 46B cubicle D32-5 Dipole Failure in Oct 2006  Mouse caused feeder fault  Glitch → D3 quench response  Dipole failed during quench  Previous D3 quench 9/11/02  Failure lying in wait?

46. f 2007 DOE Tevatron Operations Review – R. Moore 46 Tevatron Electron Lenses (TEL)  TEL-1 installed 2001; repaired & reinstalled 2006  Used mainly to clean abort gap  Few studies demonstrating (horz) compensation on pbars (2003)  Test bed for electron gun designs  TEL-2 installed 2006  Used as spare abort gap cleaner  Successful (vertical) tune-shifting on protons during HEP! TEL-2 TEL-2 on P12

47. f 2007 DOE Tevatron Operations Review – R. Moore 47 TEL-2 in Action  TEL-2 increases proton lifetime by raising vertical tune away from 7/12  TEL-1 could do same for horz tune on leading bunches of train  Little emittance growth, little/no increase in losses  Currently doing studies with TEL-1 while TEL-2 cleans abort gap  Could try simultaneous operation to level bunch tunes to help lifetime  TEL-2 Marx generator suffers from radiation damage – added steel shielding TEL-2 ON P12 TEL-2 off P12/24/36 lowest vertical tune (PACMAN) P12 intensity [E9] P36 intensity [E9]

48. f 2007 DOE Tevatron Operations Review – R. Moore 48 IPM  Detectors installation completed during 2006 shutdown  Waiting for full complement of production electronics  Observed TBT quadrupole oscillations on injection  Will improve transfer line matching, emittance dilution Protons & Pbars at Injection Proton Bunch Injection Oscillations Turn # 0 20 1 2 RMS size [mm]

49. f 2007 DOE Tevatron Operations Review – R. Moore 49 Peak Luminosity Peak Pbar Stacking Rates

50. f 2007 DOE Tevatron Operations Review – R. Moore 50 Delivered Luminosity per Week Peak Pbar Stacking Rates