Transcript document

PEP II Transverse Feedback System
Ron Akre
William Colocho
Anatoly Krasnykh
Vojtech Pacak
Dmitry Teytelman
Uli Wienands
MAC January 18, 2006
January 19, 2006
PEP TFB R.Akre
PEP II Transverse Feedback System
The PEP TFB system takes the vector sum of 2 BPMs, delays the signal by the remainder
of 1 turn and delivers a kick to the beam the next time around. Two stripline kickers, one
for X and one for Y, are used.
January 19, 2006
PEP TFB R.Akre
PEP II TFB Highlights for Run 5
New Moly Kicker Electrodes and larger, 7/16 DIN, connectors allow higher
current running in LER – LER has run for 3 days at 3 Amps.
Added phase shifters to HER receivers to independently phase X and Y
Removal of orbit offset electronics increases gain in receiver chassis.
Replace HER BPM Attenuators with higher power units
The new data acquisition system and analysis software is running and
collecting Gigabytes of data.
New LBNL 2 Tap Filter / Delay installed in LER Y since August and in HER
for a few weeks in December
G-proto in LER Y for a week in September and LER X for a few weeks in
December
January 19, 2006
PEP TFB R.Akre
PEP II Transverse Feedback System
Run 5 Resolved Hardware Problems
• 18 Log Entries associated with hardware problems
– 16 Power Amp Problems
• 14 transistors
• 5 regulator boards
– 1 High Power Filter Blown: LER Y– 1 Failed BPM Attenuators: LER 2C
January 19, 2006
PEP TFB R.Akre
PEP II TFB Receiver
Orbit offset correction are done by changing beam orbit to minimize dX
and dY signals. Receiver chassis have been modified to eliminate orbit
offset adjustment and give more gain.
Manual phase shifters added to phase HER X and HER Y independently
January 19, 2006
PEP TFB R.Akre
PEP II TFB Digital Delays
• Lawrence Berkeley Laboratory
Principal Investigators: Walter Barry and John Byrd
Alex Chin, Larry Doolittle, Alex Ratti, Jonah Weber
Phase 1: 2 - 12 bit ADC to clock data into FPGA at 238MHz
Two tap filter with 1 turn delay plus variable delay
238MHz DAC with differential output
Programmable through COM port.
Completed – Installed in LER Y August 2005
Phase 2: Record 16MS, 70mS, of data to external memory
Three trigger modes
Grow/ Damp Measurements
Fault File Data
Software trigger to capture data during running
On board EPICS control with Ethernet for programming
Final Software being completed
January 19, 2006
PEP TFB R.Akre
PEP II TFB Digital Delays
Xilinx ML300 Power I/O Board
Power
Connector
I/O Connectors
Compact Flash
Card
SLAC TFB CPU Board
System
ACE
JTAG Configuration Port
2 NIM Inputs
2 TTL Inputs
Local
Network
Ethernet
ADC0
FPGA
DDR
SDRAM
Monitor
Signal
Control
Signal
Hybrid
Splitter
DAC
ADC1
Clock Input
119 MHz Sine
Attenuator
PECL
Gate
Frequency
Doubler
Tranformer
Coupling
Power
Splitter
Red = 119 MHz Clock
Tuning Cables
Blue = 238 MHz Clock
New Digital Delays – 2 tap filter and diagnostics are being developed by LBNL
January 19, 2006
PEP TFB R.Akre
Jonah Weber LBNL
PEP II TFB Power Amplifiers and Filters
Power Amplifiers
Reliability of the power amplifiers still remain a large concern. Each of the 8
amplifiers has 8 power transistors summed for the output. During this run 5
so far we have lost about 14 output power transistors.
Largest reliability concern
During the past down time all the amplifiers have been tested and repaired
The orbit offsets and phase transients cause the amplifiers to run close to
saturation. The new digital delay two tap filters eliminate orbit offsets and
greatly reduce power requirements in the amplifers.
Filters
So far only 1 filter failure – the new 7/16 DIN connector in LER Y- did not fail,
but internal LC components did.
January 19, 2006
PEP TFB R.Akre
PEP II TFB Kickers
Uli Wienands, Anatoly Krasnykh, Artem Kulikov, Jay Langton, Many Others
New kickers with moly electrodes, redesigned coax to stripline transition, and
7/16 DIN connectors have been installed in LER.
January 19, 2006
PEP TFB R.Akre
PEP II TFB Data Acquisition System
GAGE 82G PCI 8bit 2GHz 2 Channel Digitizer 16Mb Memory
2 Cards 4 Channels – HER X and Y and LER X and Y
3rd card is on order to monitor other signals
GAGE card is clocked at
238MHz bunch frequency
Inputs are from vector sum
out of Analog Signal
Processor for X and Y
Programmable triggers:
Inputs from HER / LER
Fault, HER / LER Injection,
HER / LER Software.
Output trigger for
grow/damp measurements.
January 19, 2006
PEP TFB TRIGGER CHASSIS
PEP TFB R.Akre
PEP II TFB Data Acquisition System
Network
RECEIVER
C
A
A
B
C
D
BPM1
D
B
#1
dX1
dY1
dX1
dY1
A
A
B
C
D
BPM2
D
B
#2
238MHz
Clock
dX2
dY2
X+
XX+
X-
X KICKER
BEAM
LOADS
FILTERS
PO WER
AMPS
80pS Step
10nS Delays
PREAMPS
Y+
Y-
Y+
Y-
DIGITAL
DELAY
1 T URN
X
dX
DIGITAL
DELAY
1 T URN
Y
dY
To Y KICKER
Files are stored in central NFS space
Compiled MatLab routines for analysis of
data sets are run from a GUI
January 19, 2006
MS Windows XP
dX
dY
dX2
dY2
RECEIVER
C
ANALOG
dX
dY
SIGNAL
PROCESSOR
Connection
Monitor
Calibrated
Cable
GAGE
Lengths
PCI Scope Card
2GSPS 8bit
PEP TFB R.Akre
476MHz CLK
Turns CLK
SCP Trig
Fault Trig
Injection Trig
Trigger
Trigger
Chassis
PEP II TFB Data Acquisition System
Analysis Software
Compiled MatLab Software Run from GUI
Display All Data
Display Selected Data
Plot RMS FFT
Plot Modes
Plot Mode Phase
Plot Mode Growth Fit
High Resolution FFT
High Resolution FFT 2
Plot Spectrogram
W. Colocho, V. Pacak
January 19, 2006
PEP TFB R.Akre
X
Y
12-08-05 21:17 ~2200mA LER
X
LER CURRENT
Y
January 19, 2006
PEP TFB R.Akre
Grow Damp Measurements August 16, 2005
Mode -1
January 19, 2006
PEP TFB R.Akre
Grow Damp Measurements August 16, 2005
0.74 1/mS
0.96 1/mS
0.69 1/mS
January 19, 2006
0.63 1/mS
PEP TFB R.Akre
Grow Damp Measurements August 16, 2005
Growth Rates vs. Beam Currents
Mode -1
Growth Rate 1/mS
1.2
1
0.8
0.6
0.4
0.2
0
0
1000
2000
Beam Current mA
January 19, 2006
PEP TFB R.Akre
3000
Grow Damp Measurements August 16, 2005
January 19, 2006
PEP TFB R.Akre
PEP II TFB Concerns for Higher Current Running
Feedback Gain and Output Power
Plan to do grow / damp measurements in both HER and LER.
LBNL two tap filters have shown large increases in system gain, postponing
the need for larger power amplifiers. The new delays require less rack space
if larger power amps are required.
Filters are currently working well – 1 failures with new connector
Only 1 filter, LER Y-, has 7/16DIN connector – the rest use N connectors
(This same filter is the only one which failed during this run)
Kickers
New Moly electrodes in LER, they have handled up to 3 amps and are
expected to work to 4.5 amps.
7/16DIN Feed-through connectors replaced SC, and eliminate SC to N
adapters.
As the bunch length shortens higher frequencies of beam induced power will
need to be directed to proper loads.
Measurements of beam induced power from kicker to amplifiers need to be
done.
January 19,
2006
PEP TFB R.Akre
PEP II TFB Near Term Run 5 Tasks
• Set up collaboration with LBNL to assist with
measurements
• Measure power reflected to amplifier from kicker
– Especially LER Y-
•
•
•
•
Grow / damp measurements both planes of both rings
Transfer function measurements in both rings
Install 2 tap filters in both planes of both rings
Install 3rd GaGe card to monitor 2 additional channels
January 19, 2006
PEP TFB R.Akre