DAFNE Status Report

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DAFNE Status Report

• P. Raimondi

Scientific Committee Nov-2005
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OUTLINE

• Milestones from last SC
• Status of the Kloe run
• Plan and schedule for the off-energy Kloe run
• Schedule and plans for the Finuda Roll-in
• Conclusions

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The road toward Lgt1.5e32
now 1.4e32 Ldaygt10pb-1
now 8.6pb-1 Lmonthgt
200pb-1 now 170pb-1
Further re-activation of the pumps across the RF
cavity (5 gain), more pumps and cooling Faster
switch of the transfer lines (5 gain) Emittance
reduction (10 gain, requires a 1day MD) IP
Coupling reoptimization (10 gain, requires a
1day MD) Tunes closer to the integer or just
above the half integer (10 gain, requires 2days
MDs) The last four tests will be done
sequentially in the next month in our reserved
days (one each week).
Slide shown at the May-2005 SC
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DAFNE DELIVERED L IN YEAR 2004-5 for KLOE
109-111 bunches I-peak 2.05 A Ipeak 1.39
A Lpeak 1.53e32 cm-2s-1 Lday peak 9.4
pb-1 Lmonth gt 215 pb-1 L2004-5 gt 2000 pb-1
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DAFNE Peak rate on a 2hrs interval
Lhour peak 431nb-1/hr Corresponding to
a potential of 10.4pb-1 in 24hrs of
continuos Operations Lbest shift 3.26pb-1
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• Delivered gt215pb-1 logged 204pb-1 in 30 days!!!!!

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Peak currents

• Electron current reached record value of 2.1Amps
• Routinely exceeded 1.85Amps in collision

Positron current reached record value of
1.39Amps Routinely exceeded 1.3Amps in collision
Routinely run with 109 bunches and 111 at times
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Tune shift in Oct 2005Light Xs show the
effective tune shift once the correction for the
finite bunch lenght is appliedBlow-up from
beam-beam about 15Blow-up from other
high-current effects of the order of 10
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• Run History from May to November
• Steady run with few MDs (mainly for fbcks
  improvements).
• Long down time due to Criogenic problems,
  succesfully identified in a faulty turbine and
  fixed.
• Overall down due to criogenics about 5 weeks
  (2weeks simply due to cleaning of the system
  after some minor hardware failure)
• Additional loss of uptime due to time-sharing
  with other users (BTF and Synchrotron light
  dedicated runs)
• Main improvement in peak and integrated
  luminosity due to fbck, faster switch and
  adiabatic tuning.

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Peak luminosity evolution in 2004-5
Down due to Criogenic problems
Down and lower Integrated luminosity due to
scheduled BTF runs
Other smaller holes due to minor hardware
failures and dedicated Synchrotron Light runs
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Plans and schedule for the Kloe Run

• Our web figures for the integrated
  luminosity for Kloe have been inflated by about
  5 since the very beginning (1999!).
• We have reset our counter on the Kloe logged
  luminosity from their presenter, currently
  about 1970pb-1.
• When we reach 2000pb-1 (in a few days) we will
  start the energy scan that should be completed by
  the end of the year (about 40pb-1 needed).
• The off-energy run that requires about 200pb-1
  should take place from January to March and will
  start immediately after the recovery from the
  Xmas shutdown
• It is not yet decided what to do if we are
  lucky and we deliver the required luminosity
  earlier than March,31
• Finuda roll-in needs about 3.5 months

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Summary performance for the Kloe run

• Reached 75 of our target peak luminosity
  1.531032 instead of 2.01032
• Reached 94 of our target daily luminosity
• 9.4pb-1 instead of 10pb-1 (Dafne Units).
• Reached 110 of our target monthly luminosity
• 221pb-1 instead of 200pb-1 (Dafne Units)
• Reached our target delivered luminosity
  (2000pb-1 Dafne Units) with 2 months more w.r.t.
  our planned schedule of 16months, 85 average
  luminosity delivered w.r.t. our target

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• Dafne Upgrades for the Finuda and Dear
  runs.
• Finuda Roll-in April-July 2006
• Upgrades for the Finuda run aimed to exceed
  2.51032
• Kloe Roll-out and installation of a standard
  beam pipe with a triplet of small quads gt
• - Optics very similar to what we have now
  with Kloe
• - smaller crossing angle, more parasitic
  beam-beam, smaller piwinsky angle
• - less coupling at the IP (just two
  D-quads to adjust), smaller y-sizes
• specific luminosity like in Kloe (already
  true for the 2003-4 run)

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• 2) Remove all the broken Ion-Clearing-Electrodes
• Shield the ICE in the Wigglers with a
  metal-sheet gt
• - Smaller e-ring impedance, 30 reduction in
  bunch lenght 20-30 reduction of vertical
  emittance at high current,
• - Smaller longitudinal and transverse
  instabilities in general
• Possibly 20-30 increase in luminosity
• 3) Install the fast stripline injection-kickers
  and new tapered chambers between bends and
  kickers and kickers and septa gt
• - Better injection efficiency (from 50 to
  gt90)
• - Virtually no background during the
  injection
• - Faster injection
• - Higher positron current gt10
• - Smaller rings impedence (10-20)
• Possibly 10-20 increase in peak luminosity
  and 20-30 in integrated

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• 3) Apply a NEG or a Ti coating in the p-ring
  wigglers chambers
• - Increase of the p-electron cloud
  instability up to a factor 2
• Possibly 40-60 increase in p-current and
  luminosity
• 4) Insert a shield in the vacuum chamber across
  the compensators to reduce the number of
  parasitic beam-beam
• - Higher currents in collision gt10
• Possibly 10 increase in luminosity
• 5) Insert 2 horizontal wires in the IP area or
  in the splitters area to compenaste for the
  parasitic beam-beam
• - Higher currents in collision gt30
• Possibly 30 increase in luminosity

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• 6) Modify the wiggler poles to eliminate the
  wiggler non-linearities
• - Increase the ring energy acceptance by a
  factor 2, the toushek lifetime by a factor 4
• Possibly 10-20 increase in integrated
  luminosity
• Background decrease by a factor 2-4
• 7) Transverse feedbacks upgrade with the new SLAC
  modules and possibly new pick-ups
• - Higher currents and more stable beams
• 8) More ideas

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• Overall possible luminosity gain way in
  excess of a factor 2, 50-60 gain seems
  reasonable gt 2.51032
• Several upgrades synergic with other
  activities and top-of-the-line worldwide kickers
  (ILC), wigglers (ILC), Ti-coating (ILC,LHC)
• All the upgrades synergic with the DAFNE
  upgrade
• Further upgrades for the DEAR run to reach
  41032
• - New Interaction region with low
  chromaticity, earlier beam-separation Possibly
  30-50 more luminosity
• - Two crab cavities (one per ring) Possibly
  20-50 more luminosity (20 simply from the
  geometric factor)
• - More ideas to come

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Conclusions
Dafne has overall reached 85 of the target for
the 2004-5 Kloe run (averaging peak, monthly and
total integrated luminosity) Based on the
acquired know-how we have a clear and easy way
to further improve the machine performances for
the Finuda run and the Dear run. Moreover a lot
of the work that we will do for the Finuda and
Dear runs will great benefit the understanding of
the critical parameters for the Dafne Upgrade
(and b.t.w. will deliver more data to the
users) Many thanks to the Acceleration Division
for the great work done!!!!