Damper system in MI

1
Damper system in MI
Purpose of dampers to reduce oscillation
amplitude in trans. and long. caused
by injection error etc
All Logic Inside FPGA
Where I am currently trying to work on
2
Three-Turn Filter for Transverse Damper
Damper kick is calculated from single BPM
position reading on 3 successive turns.
3

Reduced vertical oscillation
Damping kick signal
4
Longitudinal Damper FPGA Logic
THRESH
Synchrotron Motion Velocity Filter
Bunch-by- Bunch Digital Phase Detector
ResistiveWall Pickup
-THRESH
/- KICK to DAMPER
Multi-Turn Memory
ADC
14
THRESH
Bunch Intensity FIR Filter
8 turns for weighted calculation
Individual Bunches are kicked or depending on
whether they are moving right or left in phase
5
Attempt to damp down Synchrotron oscillation
First bunch
Bunch gets kicks (?)
6

• Possible reason of ineffective longitudial
• damping kicks
• Timing or phase of kicking is not quite right
• look at the FPGA codes
• 600V might not be big enough to damp the
  oscillation
• beam injection is not performed in
  phase