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Tevatron Operations Since the Shutdown. Ron Moore Fermilab – Tevatron Dept. Shutdown/Startup Work. No big upgrades, but lots of maintenance Warmed up 4 houses for vacuum work Found/replaced unexpectedly a few (electrically) bad components

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Tevatron operations since the shutdown

Tevatron Operations Since the Shutdown

Ron Moore

Fermilab – Tevatron Dept.

Shutdown startup work
Shutdown/Startup Work

  • No big upgrades, but lots of maintenance

  • Warmed up 4 houses for vacuum work

    • Found/replaced unexpectedly a few (electrically) bad components

  • Unroll ~60 dipoles, lattice quads (including D16-1 ≈20 mrad)

  • Move CDF and D0 triplets to move IP and lower corrector currents

    • Adjusted CDF again after start-up since IP far off (?)

  • Start up with new helical orbits (horz & vert collision, vert injection)

    • Goal was to eliminate proton loss during helix transition in squeeze

    • Had to revert after high pbar loss in new transition

R. Moore - FNAL

As good as ever…

R. Moore - FNAL

Losses during squeeze
Losses during Squeeze

  • Proton loss is driven by beam-beam effects

  • New helix more complicated that initially thought

    • Flip horz collision helix in short arc to eliminate B17H separator polarity change

    • Also need vert collision helix flip to allow initiating collisions in usual way

    • Flip vert injection helix to prevent C17V separator polarity change in squeeze

  • Lost ~1/3 pbars during new helix transition in squeeze of 1st 36x36 store

    • Phase changes of helix allowed horz and vert separation minima to coincide

      • Nearly head-on collisions in many places around the ring

    • Some improvements made, but not good enough  revert to old helix scheme

  • Made improvements after tuning-up and making orbit bumps to reduce losses at CDF and D0

R. Moore - FNAL

Shot 5802 smaller proton loss during squeeze
Shot 5802 – (Smaller) Proton Loss during Squeeze



Proton Intensity


Proton Loss @ Helix Transition

Pbar Intensity





Loss Spikes



R. Moore - FNAL


  • Luminosity ramping up with beam intensities

  • D0 luminosity lower than expected

    • Made 3% improvement with alpha-bumps (horz and vert β* offset longitudinally)

    • Still not understood completely

R. Moore - FNAL

Lifetimes in hep
Lifetimes in HEP

  • Pbar lifetime is improved – almost entirely luminous

  • Proton lifetime suffering from small pbar emittances

    • Pbars 3-4 times smaller than protons

    • Greater fraction of proton bunch sees strongest beam-beam force

    • Highest head-on tune shifts for protons > 0.024

    • Trying to blow-up pbars last few stores (missteering at injection)

R. Moore - FNAL

Proton burn rates store 5802
Proton Burn Rates – Store 5802

Mary Convery

Measured burn rate

Non-luminous burn rate

Non-luminous losses dominate early in HEP

Burn rate from luminosity

R. Moore - FNAL

Jerry Annala

R. Moore - FNAL

5 store running average

R. Moore - FNAL


  • Post-shutdown start-up longer than desired

    • Adjust CDF quads (again) and revert to old helix

  • Beam losses at injection, ramp, squeeze as good or better

  • Luminosity ramping up with beam intensities

  • Proton lifetime early in HEP is an issue

    • Exacerbated by small pbar transverse emittances

  • Want higher intensities to push integrated luminosity

    • 15-20% more protons and pbars to return to pre-shutdown

    • Get back to > 40 pb-1 per week reliably

R. Moore - FNAL

Pbars in the squeeze
Pbars in the Squeeze

R. Moore - FNAL