Controlling Magnets at Jefferson Laboratory

1
Controlling Magnets at Jefferson Laboratory
2
The Magnet Record

• Provides two dependent settable fields for
  controlling magnets effect
• Magnet current (S)
• Magnet field (BDL)
• Magnet hysteresis loop control
• Magnet field map kept in each record

3
Magnet Hysteresis
4
Managing Hysteresis

• Beam reproducibility requires magnet
  reproducibility
• Keep Magnet On Loop (KMOL) mode forces magnets to
  stay on the curve
• High-level applications must work with alarm
  handlers and other tools

5
Setting a Magnets Strength

• Engineering control current
• Useful when no field map is available
• When running through the hysteresis curve
• Optice control field of the magnet
• So applications can control magnets in an
  energy-independent manner
• Magnet fudge factor

6
Magnet Alarms

• Difference alarm
• Alerts operations to a mismatch on current
• Outside range alarm
• Alerts operations to a current being clipped
• On-loop alarm
• Alerts operations to a non-reproducible magnet