Hall C Steering Coils for Qweak

1
Hall C Steering Coils for Qweak

• J. W. Martin
• University of Winnipeg

2
Motivation

• To lock the beam onto target through a feedback
  loop. (DC lock)
• Possibly, to induce/correct helicity-correlated
  beam motion. (300 Hz square wave ? high
  bandwidth)
• these would likely be different sets of coils
• University of Winnipeg contribution to Qweak.
  Corresponding increase of scope for Canadian
  group.

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Schematic
saddle coils on ceramic beam pipe
H coil
V coil
Cavity Monitor(s)
target
beam
Power amplifier
Mixing Electronics
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Typical Design Parameters

• coils placed on girder or farther upstream of
  experiment.
• provide beam motion below 1 mm at target
• saddle coils typ. 10 mA-turns.
• minimize self-inductance (typ lt 0.1 ?H) thanks to
  Litz wire.
• bandwidth into 10 kHz range.

5
Budget

• J. W. Martin Discovery Grant (NSERC) funded April
  1, 2005.
• JLab contributions, expertise (C. Yan, R. Carlini)

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Schedule

• Finalize design 2005.
• Construct/test 2006.