1 / 19

Review of Recent Tevatron Operations

Review of Recent Tevatron Operations. Ron Moore Fermilab – Tevatron Dept. Overview. Tevatron 1 km radius superconducting synchrotron at 980 GeV beam energy Tevatron 36 ×36 proton-antiproton collisions to CDF & D0 experiments 3 trains of 12 bunches each with 396 ns separation

ferris-atkinson
Télécharger la présentation

Review of Recent Tevatron Operations

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Review of RecentTevatron Operations Ron Moore Fermilab – Tevatron Dept.

  2. Overview • Tevatron • 1 km radius superconducting synchrotron at 980 GeV beam energy • Tevatron 36×36 proton-antiproton collisions to CDF & D0 experiments • 3 trains of 12 bunches each with 396 ns separation • Protons and antiprotons circulate in single beam pipe • Electrostatic separators keep beams apart except where/when desired • Beam-beam interactions (head-on & long range) play major role R. Moore - FNAL

  3. Tevatron Delivered Luminosity > 1.5 fb-1 since June 2006 R. Moore - FNAL

  4. Tevatron Run 2 Peak Luminosities Recycler-only pbars & 28 cm β* R. Moore - FNAL

  5. 2006 Tevatron Shutdown Tasks • Fixed known cold leaks in E2, A3, B4; replace failed dipole in F4 • Installed 2 new separators (B48, A17), replace 3 separators (A49) • Completed reshimming on remaining 228 dipoles • Replaced all ≈1200 helium relief valves (Kautzky) on magnets • Repaired TEL-1 and installed TEL-2 (electron lenses) • Pulled cables for new sextupole circuits (2nd order chromaticity correction) • Unrolled quads in A3 (~10 mrad); unroll ~60 magnets with small rolls • Completed IPM detector installation • Completed ring-wide hydrostatic level sensor installation • Many smaller tasks, lots of maintenance… • Tevatron Run II upgrades effectively complete! R. Moore - FNAL

  6. Highlights since 2006 shutdown… • Record delivered luminosity / week 24.4 → 44.9 pb-1 • Record peak luminosity 180 → 292 1030 cm-2 s-1 • Delivered > 1.5 fb-1 to CDF and D0 (Run 2 total delivered now > 3 fb-1) • More antiprotons with smaller emittances to HEP • Thanks to Antiproton Source and Recycler • See K. Gollwitzer’s talk tomorrow afternoon (WEZAKIO1) • More protons to HEP • Injecting ≈10% more protons • Better lifetime @ 150 GeV from new helical orbit, reduced beam-beam • Improved luminosity lifetime • Additional separators increase separation (up to 20% at parasitic crossings) • Beam-beam effects reduced • Commissioned TEL-2 and demonstrated beam-beam compensation on protons • See V. Shiltsev’s talk later this session (TUOCKI04) R. Moore - FNAL

  7. 2006 shutdown Beam Intensities in HEP Stores 9500 E9 ≈ 264 E9 / bunch 3000 E9 ≈ 83 E9 / bunch R. Moore - FNAL

  8. Improved Proton Efficiency vs Pbar Intensity New injection helix increased separation between beams  reduced beam-beam effects R. Moore - FNAL

  9. Larger Separation with New Collision Helix • Installed 2 additional separators during 2006 shutdown • Luminosity lifetime improved ~20% compared to pre-shutdown • Increased integrated luminosity per store (for similar luminosities and duration) Beam separation in σ blue – oldred – present Distance from B0 [m] R. Moore - FNAL

  10. Better Lifetime  More Delivered Luminosity Based on luminosity lifetime fits and adjusting to 24 hour store duration R. Moore - FNAL

  11. Beam Lifetimes during HEP • Pbar lifetime dominated by luminosity – good • Most protons lost in non-luminous processes – not so good • Head-on beam-beam effects from smaller emittance pbars on protons 300 225 150 75 0 Store 5245 Luminosity [μb-1/s] Pbar Lifetime / ExpectedLifetime from Luminosity 1 0.75 0.5 0.25 0 Proton Lifetime / ExpectedLifetime from Luminosity R. Moore - FNAL

  12. Store 5245 – Comparison to Model w/o Beam-Beam Luminosity Integral Model Data Initial Lumi = 286 μb-1/s ~10% luminosity loss from beam-beam effects See A. Valishev’s talk later this sesssion (TUOCKI03) R. Moore - FNAL

  13. Reliability • Over 280 HEP stores since June 2006 – 75% terminated intentionally • Slightly better than the 72% Run 2 historical average • Causes: power supplies ≈ 24%, cryo ≈ 11%, Mother Nature ≈ 10%, controls ≈ 9% , separators ≈ 7% • Averaging ≈105 HEP store hours per week since October 2006 • Includes few weeks of downtime to repair failed Tevatron components • Weeks of 130 store hours not uncommon • Reliability • Replaced all ≈1200 LHe Kautzky valves (cause of 2 FY06 dipole failures) • Modifying quench protection system to allow faster beam aborts • Cog pbars out of abort gap for acceleration – prevent needless quenches R. Moore - FNAL

  14. Looking Ahead in Tevatron • Implement 2nd order chromaticity correction @ low β – in progress • Simulations show improved lifetimes during HEP • Also prerequisite to pursue possible new working point near ½ integer • See A. Valishev poster (FRPMS015) • Pursue other minor improvements (few % each) – they all add up! • Scrape (higher intensity) protons @ 150 GeV • Can reduce losses up ramp and through squeeze? Need to resume • Investigating new cogging between antiproton injections • Reduce beam-beam effects by changing locations of long-range crossings • Use TELs (electron lenses) on protons for beam-beam compensation • Raise tunes of individual bunches away from resonance to improve lifetime • Better helices, improved transfer line matching, faster shot-setups, etc. R. Moore - FNAL

  15. Luminosity Projections with Updated Model Scenarios Peak Pbar Stacking Rate in Accumulator Goal = 8 fb-1 updated model scenarios 1 to 4 Only ≈1 fb-1 spread in total We’re in this area now 3 fb-1 ≈23 mA/hr June ‘07 R. Moore - FNAL

  16. Summary • Tevatron luminosity made great progress over past year • Doubled the delivered luminosity to > 3 fb-1 • Higher antiproton intensities with smaller emittances • Improved luminosity lifetime from increased separation • Tevatron upgrades complete, still reaping benefits • Continue pursuing smaller operational improvements • On track for 6-7 fb-1 total through October 2009 • 8 fb-1 is still the goal • Need increased antiproton stacking rates for higher luminosity • Make the most of the Tevatron before the end of Run 2! R. Moore - FNAL

  17. FY07 Tevatron Performance A18 vacuum leak E4 cryo vacuum D32-5 failure feeder 46B fault Oct 1 → June 24 R. Moore - FNAL

  18. New BPM electronics help us see this motion! E11 vert BPM [mm] Orbit stabilization ON F17 horz BPM [mm] Proton vert tune D0 proton halo [Hz] C4Q4 roll [μrad] C4Q4 pitch [μrad] Proton intensity [E9] V. Ranjbar Store 4402 Magnet Motion / Orbit Stabilization R. Moore - FNAL

  19. R. Moore - FNAL

More Related