Ramped%20Corrector%20Status

1
Ramped Corrector Status

• Eric Prebys
• FNAL Beams Division

2
B80 (PA1915) Ramped Corrector Control Program
3
Improvements

• Reduced number of breakpoints (64-gt12) to speed
  up closed orbit calculation time.
• Added improved beam steering interface. Still
  not as intuitive as 3-bumps, but better than
  before.
• Added ability to save/restore ramps.
• Improved clock event handling to facilitate
  different ramps on different clock cycles.

4
Details of Closed Orbit Calculation

• Read desired orbit (from file or a particular
  time in current cycle)
• Read the beam position as a function of time.
• Initialize the ramps.
• Calculate the current ramps needed to hold the
  orbit at the desired point.
• Calculate the predicted orbit, based on the
  calculated ramps.
• Produce some diagnostic plots
• Send the ramp current ramps to the ramp modules.
• Save ramps for future use.
• Restore ramps, either to their initial value or
  to a stored setting.

5
Steering Interface
Steer orbit relative to current desired orbit,
then recalculate current ramps.
6
Performance (Vertical Plane)
Can hold orbit fairly flat throughout cycle.
Position without ramped correctors
Position (mm)
Endpoint problem understood and (hopefully) fixed.
Position with ramped correctors
Time (ms)
7
Plan

• Want to start leaving ramps on in vertical plane.
• Need to optimize transfer line.
• Test effect on collimators, when we start using
  them.
• Horizontal plane still needs some more work.
  Going to try to hold orbit only at collimator
  position.