Report on TEL2 Progress and Studies

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Report on TEL-2 Progress and Studies

• Vsevolod Kamerdzhiev
• Vladimir Shiltsev
• Xiaolong Zhang
• Accelerator Physics Dept. meeting Nov 1, 2006

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TEL2 in the tunnel
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Types of studies

• Optimization of electron beam alignment
• Shifting tunes with dc e-beam
• Abort gap cleaning demonstration
• BBComp on P1
• BBComp on P12
• Marx generator recommissioning
• Timing jitter studies, and improvement

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First tune shift in dc mode
July 15, 2006 Ie0.5A Dedicated proton only
study, low beta High proton losses due to not
optimal e-beam alignment, PS ripple, etc.
no e-current 0.5A of e-current
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First pulsed e-beam in TEL2
Poor e-current pulse to pulse stability due to
modulator anode PS ripple Now improved to 2
level
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Abort gap cleaning
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BBComp on P12
We observe vertical tune shift of 0.0015 on the
1.7GHz Schottky gated to P12 using the modulator
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Effects on proton halo
P11 halo is higher because this bunch sees the
edge of electron pulse. Jitter results in
different e-currents from turn to turn Need to
eliminate jitter
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Jitter measurements
Optical beam sync signal is the reference
Now better than 1ns
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Mid-Store studies, 4972
Encouraging results TEL2 was On P1 for 8 hours
(EoS), generated 0.001 tuneshift and did not
spoil P1 intensity luminosity lifetimes. So,
seems that we are ready to go to use it earlier
in stores (may be start of store).  - vs
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Marx generator reinstalled
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Marx summary

• Marx generator is reinstalled in the tunnel
• Radiation shielding is added (steel)
• Remote control features are added
• Output voltage measuring circuit improved
• Advantages are
• better rise and fall times
• shorter pulses are possible (gt500nS)
• we expect better beam position measurement
  accuracy
• better pulse to pulse stability -gt better beam
  lifetime
• only one PS is needed to operate Marx gen.
• higher e-current possible

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Using Marx generator
0.6A of e-current
Pickup signal
Marx generator (solid state) replaces the
modulator (RF tube). It pulses the gun anode up
to 5 kV. Sensitive to radiation
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TEL2 beam studies activity
TEL2 average electron current Aug 23 Oct 3
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New BPM algorithm
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Other activities

• Lifetrac simulations of TEL operation tune
  shifts, lifetimes have begun
• TEL1 and TEL2 are now included in TEV optics
  files (A. Valishev, M. Martens)
• Electron gun development continues
• Feasibility study for transformer based HV pulser
  is underway (G. Saewert)

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Summary

• ?Qv 0.0015 is acheived with 0.5-0.6 A of
  electron current using both the modulator and the
  Marx generator.
• After e-beam alignment optimization halo of the
  effected bunch did not increase by much.
• While compensating P1 TEL2 added about 200hrs to
  145 hrs (TEL2 off) of lifetime.
• Timing jitter has been improved by a factor of
  10. No more lifetime deterioration due to pulse
  edge effects.
• When TEL2 was timed to P12 only its lifetime was
  50hrs.
• New position measurement algorithm implemented.
• Both TEL1 and TEL2 are now equipped with similar
  SEFT electron guns optimized for BBComp
• TEL2 e-current remote control is available
• We are ready for beginning of store studies.

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Backup slides
Vladimirs notes on lifetime during the last
BBComp study