Transcript Beam-Based Feedback Systems

MATLAB Feedback
Phase II Commissioning
June 17, 2008
LCLS FAC
D. Fairley
Topics
Feedbacks for Phase II
Early Phase II Commissioning Results
Still to do for Phase II
Challenges Ahead
Plan and Schedule for Matlab Feedbacks
Fast Feedback Plans
June 17, 2008
LCLS FAC
D. Fairley
Phase II Commissioning Results
Longitudinal Feedback commissioned thru BC2.
Currently implemented as 7 different feedbacks (4 new
loops)
Bunch Charge Feedback commissioned
Two additional feedbacks commissioned (bonus!)
Gun Launch
X Cavity Launch
Our physicists are happy with the results - report that
when the feedbacks are turned off the machine drifts
within minutes
June 17, 2008
LCLS FAC
D. Fairley
LCLS – Accelerator and Bunch Compressor Schematic
June 17, 2008
LCLS FAC
D. Fairley
Screen Shots
June 17, 2008
LCLS FAC
D. Fairley
Screen Shots
June 17, 2008
LCLS FAC
D. Fairley
Screen Shots
June 17, 2008
LCLS FAC
D. Fairley
Phase II Commissioning, cont.
Feedback Framework has been successful in
making installation and use of new feedbacks
easier.
General Purpose utilities for all feedbacks
Configuration utility
Reference Orbit collection, editting, loading
Restore Actuator utility
Start, Stop, Enable, Disable control
Setpoint scanning capability
Transverse feedbacks are easiest to clone
Has been useful for Longitudinal feedback, since
this is one feedback defined by many similar loops
June 17, 2008
LCLS FAC
D. Fairley
Phase II Commissioning, cont.
Process for making a new feedback:
If necessary, create up to three new matlab scripts for the
feedback: getMatrix function, loop init function, loop algorithm.*
Add EPICS DB template for each new feedback and re-build
soft IOC *
Create a configuration file for the feedback
Create EDM screens for the new feedback *
Update ChannelWatcher config
Add Alarms for the feedback
Archive new feedback PVs
* Usually done by copy and edit
June 17, 2008
LCLS FAC
D. Fairley
Still to go for Phase II
Several Feedbacks are not completed; we
are waiting for EPICS controlled BPMs,
Magnets, and RF.
Longitudinal must include DL2 Energy
L2 Launch
L3 Launch
June 17, 2008
LCLS FAC
D. Fairley
Challenges for Phase II
Using two klystrons to control 26+ klystrons for BC2,
sometimes there is no solution for the longitudinal
feedback.
Cross-talk between transverse feedbacks may be an
issue when L2 and L3 Launches are installed
Better cooperation between Laser-Cathode Alignment
GUI and Gun Launch could help.
We are still learning how various subsystems effect the
feedbacks (as above, cathode alignment, klystrons at
L2, charge changes, etc) and vice-versa. There will be
more adjustments as commissioning continues…
June 17, 2008
LCLS FAC
D. Fairley
Plan and Schedule
Short-term (before end of this run)
Commission L2 Launch feedback
Make Desired Energy and Desired Chirp ‘virtual’ actuators for
the longitudinal feedback. These will take an Energy and
Chirp value and control the 24-1 and 24-2 klystron phases
accordingly.
Add feedback setpoints and limits to SCORE for save/restore
Disallow 24-1 and 24-2 klystron ‘swap’ where the longitudinal
feedback settles on a solution where the klystrons flip in phase
June 17, 2008
LCLS FAC
D. Fairley
Plan and Schedule
Later (Next Commissioning Run)
Formalize reference orbit usage
Commission L3 Launch feedback
Complete the Longitudinal thru DL2
June 17, 2008
LCLS FAC
D. Fairley
Fast Feedback Plans
Feedback for 120 Hz with time-slot compensation
needed by July 2010
Feedback for 60 Hz (no time-slot issues) needed by
October 2009
General plan
move feedback data transport to a dedicated network.
Move feedback processing into an IOC.
Setup implemented in new HLA framework
June 17, 2008
LCLS FAC
D. Fairley