bunch-by-bunch feedback and diagnostics in esrf 2017-05-17 · bunch-by-bunch feedback and...
TRANSCRIPT
Bunch-by-bunch feedback and diagnostics in ESRFDemonstration of iGp12 and LNFE
D. Teytelman
Dimtel, Inc., San Jose, CA, USA
April 26, 2017
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 1 / 31
Outline
1 iGp12 introduction
2 Setup and planning
3 Single bunch studies
4 Multibunch measurements at zero chromaticity
5 Studies at nominal chromaticity
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 2 / 31
iGp12 Highlights
A 500+ MHz processingchannel.Finite Impulse Response (FIR)bunch-by-bunch filtering forfeedback.Control and diagnostics viaEPICS soft IOC on Linux.External triggers, fiducialsynchronization, low-speedADCs/DACs, general-purposedigital I/O.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 3 / 31
Front/Back-end Unit
3 front-end channels.1–1.5 GHz front-end detectionfrequency.2-cycle comb generator.1–1.5 GHz back-endfrequency.Integrated control via iGp:
I LO phase shifters;I Attenuators;I Temperature measurement
and stabilization.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 4 / 31
Front/Back-end Unit
3 front-end channels.1–1.5 GHz front-end detectionfrequency.2-cycle comb generator.1–1.5 GHz back-endfrequency.Integrated control via iGp:
I LO phase shifters;I Attenuators;I Temperature measurement
and stabilization.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 4 / 31
Front/Back-end Unit
3 front-end channels.1–1.5 GHz front-end detectionfrequency.2-cycle comb generator.1–1.5 GHz back-endfrequency.Integrated control via iGp:
I LO phase shifters;I Attenuators;I Temperature measurement
and stabilization.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 4 / 31
Front/Back-end Unit
3 front-end channels.1–1.5 GHz front-end detectionfrequency.2-cycle comb generator.1–1.5 GHz back-endfrequency.Integrated control via iGp:
I LO phase shifters;I Attenuators;I Temperature measurement
and stabilization.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 4 / 31
Front/Back-end Unit
3 front-end channels.1–1.5 GHz front-end detectionfrequency.2-cycle comb generator.1–1.5 GHz back-endfrequency.Integrated control via iGp:
I LO phase shifters;I Attenuators;I Temperature measurement
and stabilization.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 4 / 31
Front/Back-end Block Diagram
ΣΣ
iGp GPIODigital controlinterface
Two cycle comb filter MixerVariableattenuator
amplifierTo the power
To the ADC
Low-pass filterAmplifier
Phase shifter 3× frf
2× frf
Bandpass filterAmplifierVariable attenuator
Back-end section
Mixer
×
×
frequency multiplierStep recovery diode
3× multiplier
2× multiplier
Step recovery diodefrequency multiplier
From the DAC
frf
hybridFrom BPM
Front-end section
Front-end channel (×3)
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 5 / 31
iGp12 Specifications
Design goals:I Reliability;I Maintainability;I Ease of use;I Diagnostics.
FPGA based processing:I Flexible;I Field upgradable.
SpecificationsBunch spacing ≥ 1.9 ns
Harmonic number 32–5120ADC resolution 12 bitsDAC resolution 12 bits
ADC bandwidth 1.35 GHzFeedback filter 32-tap FIRDownsampling 1-256DAQ memory 12 MS
Triggers 2
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 6 / 31
Waveform Panel
Updates at 2 HzUses data from allbunches over manyturns (12672 forESRF).Four waveforms:
I Mean;I RMS;I Bunch with largest
RMS;I Averaged spectrum
of all bunches.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 7 / 31
Waveform Panel
Updates at 2 HzUses data from allbunches over manyturns (12672 forESRF).Four waveforms:
I Mean;I RMS;I Bunch with largest
RMS;I Averaged spectrum
of all bunches.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 7 / 31
Waveform Panel
Updates at 2 HzUses data from allbunches over manyturns (12672 forESRF).Four waveforms:
I Mean;I RMS;I Bunch with largest
RMS;I Averaged spectrum
of all bunches.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 7 / 31
Waveform Panel
Updates at 2 HzUses data from allbunches over manyturns (12672 forESRF).Four waveforms:
I Mean;I RMS;I Bunch with largest
RMS;I Averaged spectrum
of all bunches.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 7 / 31
Feedback in Action
With feedback off wesee vertical oscillation(28.6 dB peak);When feedback isturned on, verticalmotion is suppressedto the noise floor;
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 8 / 31
Feedback in Action
With feedback off wesee vertical oscillation(28.6 dB peak);When feedback isturned on, verticalmotion is suppressedto the noise floor;
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 8 / 31
Outline
1 iGp12 introduction
2 Setup and planning
3 Single bunch studies
4 Multibunch measurements at zero chromaticity
5 Studies at nominal chromaticity
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 9 / 31
Day by Day SummarySunday (2017-04-23):
I Unpacked the hardware;I Network and signal connections;I Passive monitoring with ESRF front-end;I Dimtel LNFE setup.
Monday (2017-04-24):I Adjusted timing to the BPM hybrid to optimize common mode
rejection;I Parasitically timed the front-end;I Using very low amplitude single bunch excitation timed the
back-end;I Set up multibunch feedback;I Checked notch monitoring, tune tracking, single bunch transfer
function.Tuesday (2017-04-25):
I MDT shift from 8:00 to 19:00;I Covered 9 out of 10 items in the plan.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 10 / 31
Day by Day SummarySunday (2017-04-23):
I Unpacked the hardware;I Network and signal connections;I Passive monitoring with ESRF front-end;I Dimtel LNFE setup.
Monday (2017-04-24):I Adjusted timing to the BPM hybrid to optimize common mode
rejection;I Parasitically timed the front-end;I Using very low amplitude single bunch excitation timed the
back-end;I Set up multibunch feedback;I Checked notch monitoring, tune tracking, single bunch transfer
function.Tuesday (2017-04-25):
I MDT shift from 8:00 to 19:00;I Covered 9 out of 10 items in the plan.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 10 / 31
Day by Day SummarySunday (2017-04-23):
I Unpacked the hardware;I Network and signal connections;I Passive monitoring with ESRF front-end;I Dimtel LNFE setup.
Monday (2017-04-24):I Adjusted timing to the BPM hybrid to optimize common mode
rejection;I Parasitically timed the front-end;I Using very low amplitude single bunch excitation timed the
back-end;I Set up multibunch feedback;I Checked notch monitoring, tune tracking, single bunch transfer
function.Tuesday (2017-04-25):
I MDT shift from 8:00 to 19:00;I Covered 9 out of 10 items in the plan.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 10 / 31
Setup
Baseband processor (iGp12)and 352 MHz low noisefront-end (LNFE);Dimtel BPMH-20-2G hybridprocesses 4 button signals togenerate ∆Y , ∆X , and Σ;Differential DAC output drivestwo power amplifiers directly.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 11 / 31
Setup
Baseband processor (iGp12)and 352 MHz low noisefront-end (LNFE);Dimtel BPMH-20-2G hybridprocesses 4 button signals togenerate ∆Y , ∆X , and Σ;Differential DAC output drivestwo power amplifiers directly.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 11 / 31
Setup
Baseband processor (iGp12)and 352 MHz low noisefront-end (LNFE);Dimtel BPMH-20-2G hybridprocesses 4 button signals togenerate ∆Y , ∆X , and Σ;Differential DAC output drivestwo power amplifiers directly.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 11 / 31
The Plan
! Single bunch timing and calibration @ 8 mA, high chromaticity;! Single bunch limits vs. chromaticity, gaps open and closed;
! Feedback operation: zero chromaticity, uniform fill;! Characterization of growth rates;! Bunch cleaning (zero chromaticity);! Parasitic tune monitoring.
! Standard 7/8 fill, high chromaticity! Tune monitoring tools! Bunch cleaning
! Injection studies;% Operate with the current (ESRF) front end.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 12 / 31
The Plan
! Single bunch timing and calibration @ 8 mA, high chromaticity;! Single bunch limits vs. chromaticity, gaps open and closed;
! Feedback operation: zero chromaticity, uniform fill;! Characterization of growth rates;! Bunch cleaning (zero chromaticity);! Parasitic tune monitoring.
! Standard 7/8 fill, high chromaticity! Tune monitoring tools! Bunch cleaning
! Injection studies;% Operate with the current (ESRF) front end.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 12 / 31
The Plan
! Single bunch timing and calibration @ 8 mA, high chromaticity;! Single bunch limits vs. chromaticity, gaps open and closed;
! Feedback operation: zero chromaticity, uniform fill;! Characterization of growth rates;! Bunch cleaning (zero chromaticity);! Parasitic tune monitoring.
! Standard 7/8 fill, high chromaticity! Tune monitoring tools! Bunch cleaning
! Injection studies;% Operate with the current (ESRF) front end.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 12 / 31
The Plan
! Single bunch timing and calibration @ 8 mA, high chromaticity;! Single bunch limits vs. chromaticity, gaps open and closed;
! Feedback operation: zero chromaticity, uniform fill;! Characterization of growth rates;! Bunch cleaning (zero chromaticity);! Parasitic tune monitoring.
! Standard 7/8 fill, high chromaticity! Tune monitoring tools! Bunch cleaning
! Injection studies;% Operate with the current (ESRF) front end.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 12 / 31
The Plan
! Single bunch timing and calibration @ 8 mA, high chromaticity;! Single bunch limits vs. chromaticity, gaps open and closed;
! Feedback operation: zero chromaticity, uniform fill;! Characterization of growth rates;! Bunch cleaning (zero chromaticity);! Parasitic tune monitoring.
! Standard 7/8 fill, high chromaticity! Tune monitoring tools! Bunch cleaning
! Injection studies;% Operate with the current (ESRF) front end.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 12 / 31
Outline
1 iGp12 introduction
2 Setup and planning
3 Single bunch studies
4 Multibunch measurements at zero chromaticity
5 Studies at nominal chromaticity
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 13 / 31
Calibration
−150 −100 −50 0 50 100 150130
140
150
160
170
180
190
200
210
220
Vertical bump (µm)
AD
C c
ou
nts
pe
r m
A
Vertical calibration factor 0.36 counts/µm/mA
Configured 9 dB of attenuationto handle apparent orbit offset;Calibration factor is0.36 counts/µm/mA;Centering the beam requires a−476 µm bump;At this offset can supportsingle bunch currents up to12 mA;Much higher sensitivities arefeasible with better pickup (β)and orbit offset trimming.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 14 / 31
Calibration
−150 −100 −50 0 50 100 150130
140
150
160
170
180
190
200
210
220
Vertical bump (µm)
AD
C c
ou
nts
pe
r m
A
Vertical calibration factor 0.36 counts/µm/mA
Configured 9 dB of attenuationto handle apparent orbit offset;Calibration factor is0.36 counts/µm/mA;Centering the beam requires a−476 µm bump;At this offset can supportsingle bunch currents up to12 mA;Much higher sensitivities arefeasible with better pickup (β)and orbit offset trimming.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 14 / 31
Calibration
−150 −100 −50 0 50 100 150130
140
150
160
170
180
190
200
210
220
Vertical bump (µm)
AD
C c
ou
nts
pe
r m
A
Vertical calibration factor 0.36 counts/µm/mA
Configured 9 dB of attenuationto handle apparent orbit offset;Calibration factor is0.36 counts/µm/mA;Centering the beam requires a−476 µm bump;At this offset can supportsingle bunch currents up to12 mA;Much higher sensitivities arefeasible with better pickup (β)and orbit offset trimming.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 14 / 31
Calibration
−150 −100 −50 0 50 100 150130
140
150
160
170
180
190
200
210
220
Vertical bump (µm)
AD
C c
ou
nts
pe
r m
A
Vertical calibration factor 0.36 counts/µm/mA
Configured 9 dB of attenuationto handle apparent orbit offset;Calibration factor is0.36 counts/µm/mA;Centering the beam requires a−476 µm bump;At this offset can supportsingle bunch currents up to12 mA;Much higher sensitivities arefeasible with better pickup (β)and orbit offset trimming.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 14 / 31
Calibration
−150 −100 −50 0 50 100 150130
140
150
160
170
180
190
200
210
220
Vertical bump (µm)
AD
C c
ou
nts
pe
r m
A
Vertical calibration factor 0.36 counts/µm/mA
Configured 9 dB of attenuationto handle apparent orbit offset;Calibration factor is0.36 counts/µm/mA;Centering the beam requires a−476 µm bump;At this offset can supportsingle bunch currents up to12 mA;Much higher sensitivities arefeasible with better pickup (β)and orbit offset trimming.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 14 / 31
Maximum Single Bunch Current vs. Chromaticity
0 2 4 6 8 10 120
2
4
6
8
10
12
Vertical chromaticity
Ma
xim
um
bu
nch
cu
rre
nt
(mA
)
0 2 4 6 8 10 121
1.5
2
2.5
3
3.5
Vertical chromaticity
Ra
tio
Feedback off
Feedback on
A bit of feedback tuning ateach point;Could definitely benefit frommore tuning time;Roughly consistent with theresults from the existingsystem;Modifying feedback duringinjection might help extend thelimit.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 15 / 31
Maximum Single Bunch Current vs. Chromaticity
0 2 4 6 8 10 120
2
4
6
8
10
12
Vertical chromaticity
Ma
xim
um
bu
nch
cu
rre
nt
(mA
)
0 2 4 6 8 10 121
1.5
2
2.5
3
3.5
Vertical chromaticity
Ra
tio
Feedback off
Feedback on
A bit of feedback tuning ateach point;Could definitely benefit frommore tuning time;Roughly consistent with theresults from the existingsystem;Modifying feedback duringinjection might help extend thelimit.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 15 / 31
Maximum Single Bunch Current vs. Chromaticity
0 2 4 6 8 10 120
2
4
6
8
10
12
Vertical chromaticity
Ma
xim
um
bu
nch
cu
rre
nt
(mA
)
0 2 4 6 8 10 121
1.5
2
2.5
3
3.5
Vertical chromaticity
Ra
tio
Feedback off
Feedback on
A bit of feedback tuning ateach point;Could definitely benefit frommore tuning time;Roughly consistent with theresults from the existingsystem;Modifying feedback duringinjection might help extend thelimit.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 15 / 31
Maximum Single Bunch Current vs. Chromaticity
0 2 4 6 8 10 120
2
4
6
8
10
12
Vertical chromaticity
Ma
xim
um
bu
nch
cu
rre
nt
(mA
)
0 2 4 6 8 10 121
1.5
2
2.5
3
3.5
Vertical chromaticity
Ra
tio
Feedback off
Feedback on
A bit of feedback tuning ateach point;Could definitely benefit frommore tuning time;Roughly consistent with theresults from the existingsystem;Modifying feedback duringinjection might help extend thelimit.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 15 / 31
Single Bunch Grow/Damp Measurement
0 100 200 300 400 500 600 70020
40
60
80
100
120
140
160
180
Time (µs)
Am
plit
ud
e (
µm
)
Single bunch grow/damp at 2~mA, zero chromaticity
0 100 200 300 400 500 600 700−150
−140
−130
−120
−110
−100
−90
−80
Time (µs)
Ph
ase
(d
eg
ree
s)
Oscillation phase relative to 149~kHz
Zero chromaticity, 2 mA;Feedback is turned off for180 µs;Growth looks linear;Reactive feedback setup —closed loop induces frequencyshift.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 16 / 31
Single Bunch Grow/Damp Measurement
0 100 200 300 400 500 600 70020
40
60
80
100
120
140
160
180
Time (µs)
Am
plit
ud
e (
µm
)
Single bunch grow/damp at 2~mA, zero chromaticity
0 100 200 300 400 500 600 700−150
−140
−130
−120
−110
−100
−90
−80
Time (µs)
Ph
ase
(d
eg
ree
s)
Oscillation phase relative to 149~kHz
Zero chromaticity, 2 mA;Feedback is turned off for180 µs;Growth looks linear;Reactive feedback setup —closed loop induces frequencyshift.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 16 / 31
Single Bunch Grow/Damp Measurement
0 100 200 300 400 500 600 70020
40
60
80
100
120
140
160
180
Time (µs)
Am
plit
ud
e (
µm
)
Single bunch grow/damp at 2~mA, zero chromaticity
0 100 200 300 400 500 600 700−150
−140
−130
−120
−110
−100
−90
−80
Time (µs)
Ph
ase
(d
eg
ree
s)
Oscillation phase relative to 149~kHz
Zero chromaticity, 2 mA;Feedback is turned off for180 µs;Growth looks linear;Reactive feedback setup —closed loop induces frequencyshift.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 16 / 31
Single Bunch Grow/Damp Measurement
0 100 200 300 400 500 600 70020
40
60
80
100
120
140
160
180
Time (µs)
Am
plit
ud
e (
µm
)
Single bunch grow/damp at 2~mA, zero chromaticity
0 100 200 300 400 500 600 700−150
−140
−130
−120
−110
−100
−90
−80
Time (µs)
Ph
ase
(d
eg
ree
s)
Oscillation phase relative to 149~kHz
Zero chromaticity, 2 mA;Feedback is turned off for180 µs;Growth looks linear;Reactive feedback setup —closed loop induces frequencyshift.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 16 / 31
Outline
1 iGp12 introduction
2 Setup and planning
3 Single bunch studies
4 Multibunch measurements at zero chromaticity
5 Studies at nominal chromaticity
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 17 / 31
Grow/damp Measurements
Grow/damp at 100 mA, 8 msgrowth time;Only resistive wall modes;Damping rates non-uniform —low frequency response of theamplifier?Fits look very clean, textbookexponential transients;Filled to 200 mA, not limited byinstabilities;Growth time too long, whenfeedback turns on there is notenough gain to damp themotion.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 18 / 31
Grow/damp Measurements
Grow/damp at 100 mA, 8 msgrowth time;Only resistive wall modes;Damping rates non-uniform —low frequency response of theamplifier?Fits look very clean, textbookexponential transients;Filled to 200 mA, not limited byinstabilities;Growth time too long, whenfeedback turns on there is notenough gain to damp themotion.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 18 / 31
Grow/damp Measurements
Grow/damp at 100 mA, 8 msgrowth time;Only resistive wall modes;Damping rates non-uniform —low frequency response of theamplifier?Fits look very clean, textbookexponential transients;Filled to 200 mA, not limited byinstabilities;Growth time too long, whenfeedback turns on there is notenough gain to damp themotion.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 18 / 31
Grow/damp Measurements
0 5 10 15 20 25 30 35 400
2
4
6
µm
apr2517/123303 Data, Fit and Error for Mode #987
Data
Fit
Error
0 5 10 15 20 25 30 35 400
10
20
µm
Mode #988
Data
Fit
Error
0 5 10 15 20 25 30 35 400
10
20
30
µm
Mode #989
Data
Fit
Error
0 5 10 15 20 25 30 35 400
10
20
30
µm
Mode #990
Data
Fit
Error
0 5 10 15 20 25 30 35 400
100
200
Time (ms)
µm
Mode #991
Data
Fit
Error
Grow/damp at 100 mA, 8 msgrowth time;Only resistive wall modes;Damping rates non-uniform —low frequency response of theamplifier?Fits look very clean, textbookexponential transients;Filled to 200 mA, not limited byinstabilities;Growth time too long, whenfeedback turns on there is notenough gain to damp themotion.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 18 / 31
Grow/damp Measurements
Grow/damp at 100 mA, 8 msgrowth time;Only resistive wall modes;Damping rates non-uniform —low frequency response of theamplifier?Fits look very clean, textbookexponential transients;Filled to 200 mA, not limited byinstabilities;Growth time too long, whenfeedback turns on there is notenough gain to damp themotion.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 18 / 31
Grow/damp Measurements
0 1 2 3 4 5 60
50
100
150
200
250
300
Time (ms)
Am
plit
ud
e (
µm
)
Grow/damp at 100 mA, 8 msgrowth time;Only resistive wall modes;Damping rates non-uniform —low frequency response of theamplifier?Fits look very clean, textbookexponential transients;Filled to 200 mA, not limited byinstabilities;Growth time too long, whenfeedback turns on there is notenough gain to damp themotion.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 18 / 31
Spectral Notch Tune Monitoring
130 132 134 136 138 140 14210
−3
10−2
10−1
Frequency (kHz)
Ma
gn
itu
de
(A
DC
co
un
ts)
Zero chromaticity, uniform fill, 100 mA
In closed loop operation,feedback signals show a notchat the betatron frequency;Beam response is resonant atthe tune frequency;Attenuation of detection noiseby the feedback is proportionalto the loop gain;Transfer gain from noise to thefeedback input is 1
1+L(ω)
Maximum attenuation at theresonance, thus a notch.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 19 / 31
Spectral Notch Tune Monitoring
∑ Error
Transverse position
DisturbancesDetection noise
Feedback Beam
In closed loop operation,feedback signals show a notchat the betatron frequency;Beam response is resonant atthe tune frequency;Attenuation of detection noiseby the feedback is proportionalto the loop gain;Transfer gain from noise to thefeedback input is 1
1+L(ω)
Maximum attenuation at theresonance, thus a notch.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 19 / 31
Spectral Notch Tune Monitoring
∑ Error
Transverse position
DisturbancesDetection noise
Feedback Beam
In closed loop operation,feedback signals show a notchat the betatron frequency;Beam response is resonant atthe tune frequency;Attenuation of detection noiseby the feedback is proportionalto the loop gain;Transfer gain from noise to thefeedback input is 1
1+L(ω)
Maximum attenuation at theresonance, thus a notch.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 19 / 31
Spectral Notch Tune Monitoring
∑ Error
Transverse position
DisturbancesDetection noise
Feedback Beam
In closed loop operation,feedback signals show a notchat the betatron frequency;Beam response is resonant atthe tune frequency;Attenuation of detection noiseby the feedback is proportionalto the loop gain;Transfer gain from noise to thefeedback input is 1
1+L(ω)
Maximum attenuation at theresonance, thus a notch.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 19 / 31
Spectral Notch Tune Monitoring
∑ Error
Transverse position
DisturbancesDetection noise
Feedback Beam
In closed loop operation,feedback signals show a notchat the betatron frequency;Beam response is resonant atthe tune frequency;Attenuation of detection noiseby the feedback is proportionalto the loop gain;Transfer gain from noise to thefeedback input is 1
1+L(ω)
Maximum attenuation at theresonance, thus a notch.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 19 / 31
Tune Monitoring Example
Tune tracking duringinjection from 10 to200 mA;Done by the iGp12 at2 Hz update rate:
I Exponentialaveraging of 5sweeps (2.5 s timeconstant);
I Minimum search in120–150 kHz range.
Network port changearound −4 minutemark.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 20 / 31
Tune Monitoring Example
Tune tracking duringinjection from 10 to200 mA;Done by the iGp12 at2 Hz update rate:
I Exponentialaveraging of 5sweeps (2.5 s timeconstant);
I Minimum search in120–150 kHz range.
Network port changearound −4 minutemark.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 20 / 31
Tune Monitoring Example
Tune tracking duringinjection from 10 to200 mA;Done by the iGp12 at2 Hz update rate:
I Exponentialaveraging of 5sweeps (2.5 s timeconstant);
I Minimum search in120–150 kHz range.
Network port changearound −4 minutemark.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 20 / 31
All Mode Scan: Technique
0 5 10 15 20 250
0.5
1
1.5
2
2.5
3x 10
4
Time (ms)
Am
plit
ud
e (
arb
. u
nits)
Mode 1
Mode −2
Mode −1
Performed at 15.4 mA (underthe threshold of instability);Each mode is excited to asmall amplitude underfeedback control;In a transient measurementexcitation and feedback areturned off;Capturing 21 ms of beammotion twice a second,16.5 minutes to scan allmodes;27 GiB data set.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 21 / 31
All Mode Scan: Technique
0 5 10 15 20 250
0.5
1
1.5
2
2.5
3x 10
4
Time (ms)
Am
plit
ud
e (
arb
. u
nits)
Mode 1
Mode −2
Mode −1
Performed at 15.4 mA (underthe threshold of instability);Each mode is excited to asmall amplitude underfeedback control;In a transient measurementexcitation and feedback areturned off;Capturing 21 ms of beammotion twice a second,16.5 minutes to scan allmodes;27 GiB data set.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 21 / 31
All Mode Scan: Technique
0 5 10 15 20 250
0.5
1
1.5
2
2.5
3x 10
4
Time (ms)
Am
plit
ud
e (
arb
. u
nits)
Mode 1
Mode −2
Mode −1
Performed at 15.4 mA (underthe threshold of instability);Each mode is excited to asmall amplitude underfeedback control;In a transient measurementexcitation and feedback areturned off;Capturing 21 ms of beammotion twice a second,16.5 minutes to scan allmodes;27 GiB data set.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 21 / 31
All Mode Scan: Technique
0 5 10 15 20 250
0.5
1
1.5
2
2.5
3x 10
4
Time (ms)
Am
plit
ud
e (
arb
. u
nits)
Mode 1
Mode −2
Mode −1
Performed at 15.4 mA (underthe threshold of instability);Each mode is excited to asmall amplitude underfeedback control;In a transient measurementexcitation and feedback areturned off;Capturing 21 ms of beammotion twice a second,16.5 minutes to scan allmodes;27 GiB data set.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 21 / 31
All Mode Scan: Technique
0 5 10 15 20 250
0.5
1
1.5
2
2.5
3x 10
4
Time (ms)
Am
plit
ud
e (
arb
. u
nits)
Mode 1
Mode −2
Mode −1
Performed at 15.4 mA (underthe threshold of instability);Each mode is excited to asmall amplitude underfeedback control;In a transient measurementexcitation and feedback areturned off;Capturing 21 ms of beammotion twice a second,16.5 minutes to scan allmodes;27 GiB data set.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 21 / 31
All Mode Scan: Results
0 100 200 300 400 500−250
−200
−150
−100
−50
0
Mode number
Gro
wth
rate
(s−
1)
Upper sideband
Lower sideband
Automated processing extractsgrowth or damping rates;Clear resistive wall signature;A band of higher order modesaround mode −365(129 + N × 352 MHz);A smaller HOM band around−298 (105 + N × 352 MHz);Radiation damping rate118 s−1 (8.5 ms dampingtime).
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 22 / 31
All Mode Scan: Results
0 100 200 300 400 500−250
−200
−150
−100
−50
0
Mode number
Gro
wth
rate
(s−
1)
Upper sideband
Lower sideband
Automated processing extractsgrowth or damping rates;Clear resistive wall signature;A band of higher order modesaround mode −365(129 + N × 352 MHz);A smaller HOM band around−298 (105 + N × 352 MHz);Radiation damping rate118 s−1 (8.5 ms dampingtime).
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 22 / 31
All Mode Scan: Results
0 100 200 300 400 500−250
−200
−150
−100
−50
0
Mode number
Gro
wth
rate
(s−
1)
Upper sideband
Lower sideband
Automated processing extractsgrowth or damping rates;Clear resistive wall signature;A band of higher order modesaround mode −365(129 + N × 352 MHz);A smaller HOM band around−298 (105 + N × 352 MHz);Radiation damping rate118 s−1 (8.5 ms dampingtime).
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 22 / 31
All Mode Scan: Results
0 100 200 300 400 500−250
−200
−150
−100
−50
0
Mode number
Gro
wth
rate
(s−
1)
Upper sideband
Lower sideband
Automated processing extractsgrowth or damping rates;Clear resistive wall signature;A band of higher order modesaround mode −365(129 + N × 352 MHz);A smaller HOM band around−298 (105 + N × 352 MHz);Radiation damping rate118 s−1 (8.5 ms dampingtime).
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 22 / 31
All Mode Scan: Results
0 100 200 300 400 500−250
−200
−150
−100
−50
0
Mode number
Gro
wth
rate
(s−
1)
Upper sideband
Lower sideband
Automated processing extractsgrowth or damping rates;Clear resistive wall signature;A band of higher order modesaround mode −365(129 + N × 352 MHz);A smaller HOM band around−298 (105 + N × 352 MHz);Radiation damping rate118 s−1 (8.5 ms dampingtime).
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 22 / 31
Outline
1 iGp12 introduction
2 Setup and planning
3 Single bunch studies
4 Multibunch measurements at zero chromaticity
5 Studies at nominal chromaticity
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 23 / 31
Bunch Cleaning
Started with scraper at 1.5,tested at 3.0, then 4.5;Cleaning works fine at 1.5 and3.0, somewhat touchy at 4.5;Need a bit of parameteroptimization, most likely cansupport reliable cleaning atscraper gap of 3.5–4.5.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 24 / 31
Bunch Cleaning
Started with scraper at 1.5,tested at 3.0, then 4.5;Cleaning works fine at 1.5 and3.0, somewhat touchy at 4.5;Need a bit of parameteroptimization, most likely cansupport reliable cleaning atscraper gap of 3.5–4.5.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 24 / 31
Bunch Cleaning
Started with scraper at 1.5,tested at 3.0, then 4.5;Cleaning works fine at 1.5 and3.0, somewhat touchy at 4.5;Need a bit of parameteroptimization, most likely cansupport reliable cleaning atscraper gap of 3.5–4.5.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 24 / 31
Single Bunch Transfer Function
120 125 130 135 140 145 150 155−70
−65
−60
−55
−50
−45
−40
Frequency (kHz)
Ma
gn
itu
de
(d
B)
Beam Transfer Function
120 125 130 135 140 145 150 155−200
−150
−100
−50
0
50
100
Frequency (kHz)
Ph
ase
(d
eg
)
Turn off feedback for bunch 40;Apply swept sinusoidalexcitation;Measure beam transferfunction;A simple-minded fit of aresonant response;Fit a linear combination of 3resonances;5 resonances;7 resonances;9 resonances;11 resonances.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 25 / 31
Single Bunch Transfer Function
120 125 130 135 140 145 150 155−70
−65
−60
−55
−50
−45
−40
Frequency (kHz)
Ma
gn
itu
de
(d
B)
Center frequency=136.01 kHz, τ=0.1 ms
120 125 130 135 140 145 150 155−200
−150
−100
−50
0
50
100
Frequency (kHz)
Ph
ase
(d
eg
)
Turn off feedback for bunch 40;Apply swept sinusoidalexcitation;Measure beam transferfunction;A simple-minded fit of aresonant response;Fit a linear combination of 3resonances;5 resonances;7 resonances;9 resonances;11 resonances.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 25 / 31
Single Bunch Transfer Function
120 125 130 135 140 145 150 155−70
−65
−60
−55
−50
−45
−40
Frequency (kHz)
Ma
gn
itu
de
(d
B)
Center frequency=136.09 kHz, τ=0.5 ms
120 125 130 135 140 145 150 155−200
−150
−100
−50
0
50
100
Frequency (kHz)
Ph
ase
(d
eg
)
∆f=[−1.5 1.7] kHz; τ=[0.3 0.1] ms
Turn off feedback for bunch 40;Apply swept sinusoidalexcitation;Measure beam transferfunction;A simple-minded fit of aresonant response;Fit a linear combination of 3resonances;5 resonances;7 resonances;9 resonances;11 resonances.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 25 / 31
Single Bunch Transfer Function
120 125 130 135 140 145 150 155−70
−65
−60
−55
−50
−45
−40
Frequency (kHz)
Ma
gn
itu
de
(d
B)
Center frequency=136.03 kHz, τ=0.6 ms
120 125 130 135 140 145 150 155−200
−150
−100
−50
0
50
100
Frequency (kHz)
Ph
ase
(d
eg
)
∆f=[−1.8 1.8 −3.6 3.3] kHz; τ=[0.5 0.4 0.5 0.2] ms
Turn off feedback for bunch 40;Apply swept sinusoidalexcitation;Measure beam transferfunction;A simple-minded fit of aresonant response;Fit a linear combination of 3resonances;5 resonances;7 resonances;9 resonances;11 resonances.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 25 / 31
Single Bunch Transfer Function
120 125 130 135 140 145 150 155−70
−65
−60
−55
−50
−45
−40
Frequency (kHz)
Ma
gn
itu
de
(d
B)
Center frequency=135.97 kHz, τ=0.7 ms
120 125 130 135 140 145 150 155−200
−150
−100
−50
0
50
100
Frequency (kHz)
Ph
ase
(d
eg
)
∆f=[−1.8 1.9 −3.7 3.6 −5.7 5.4] kHz; τ=[0.7 0.6 0.5 0.6 0.3 0.2] ms
Turn off feedback for bunch 40;Apply swept sinusoidalexcitation;Measure beam transferfunction;A simple-minded fit of aresonant response;Fit a linear combination of 3resonances;5 resonances;7 resonances;9 resonances;11 resonances.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 25 / 31
Single Bunch Transfer Function
120 125 130 135 140 145 150 155−70
−65
−60
−55
−50
−45
−40
Frequency (kHz)
Ma
gn
itu
de
(d
B)
Center frequency=135.96 kHz, τ=0.8 ms
120 125 130 135 140 145 150 155−200
−150
−100
−50
0
50
100
Frequency (kHz)
Ph
ase
(d
eg
)
∆f=[−1.8 1.9 −3.7 3.6 −5.8 5.5 −7.8 7.3] kHz; τ=[0.7 0.7 0.7 0.5 0.4 0.5 0.2 0.2] ms
Turn off feedback for bunch 40;Apply swept sinusoidalexcitation;Measure beam transferfunction;A simple-minded fit of aresonant response;Fit a linear combination of 3resonances;5 resonances;7 resonances;9 resonances;11 resonances.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 25 / 31
Single Bunch Transfer Function
120 125 130 135 140 145 150 155−70
−65
−60
−55
−50
−45
−40
Frequency (kHz)
Ma
gn
itu
de
(d
B)
Center frequency=136.00 kHz, τ=0.7 ms
120 125 130 135 140 145 150 155−200
−150
−100
−50
0
50
100
Frequency (kHz)
Ph
ase
(d
eg
)
∆f=[−1.8 1.8 −3.7 3.5 −5.9 5.4 −7.9 7.4] kHz; τ=[0.9 0.6 0.7 0.6 0.4 0.5 0.2 0.7] ms
Turn off feedback for bunch 40;Apply swept sinusoidalexcitation;Measure beam transferfunction;A simple-minded fit of aresonant response;Fit a linear combination of 3resonances;5 resonances;7 resonances;9 resonances;11 resonances.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 25 / 31
Single Bunch Phase Tracking
CORDIC
Aφ → IQ
A
φ
sin
cosz−1
Integrator andrange limiter
I
Q
CORDIC
IQ → Aφ
A
φ
Beam
Full scale
Phase accumulator
Beam excitation
Drive frequency
Drive amplitudeDDS-based sinusoidal drive generator
Drive frequency modulation
Phase shift setpoint
I
Q
sincos
DDC+CICBeam response
A single bunch is excited with a sinusoidal excitation at lowamplitude (20–40 µm);Response is detected relative to the excitation to determine thephase shiftIn closed loop, phase tracker adjusts the excitation frequency tomaintain the correct phase shift value;Adjustable integration time, tracking range, loop gain.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 26 / 31
Phase Tracking and Chromaticity Measurement
Close the loop at −45 s;Slow settling at low gain,faster as the gain israised;Chromaticity scan with10 Hz steps;Return step of 40 Hz istoo large, tracker locks atthe wrong point;Open and close the loopto re-lock.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 27 / 31
Phase Tracking and Chromaticity Measurement
Close the loop at −45 s;Slow settling at low gain,faster as the gain israised;Chromaticity scan with10 Hz steps;Return step of 40 Hz istoo large, tracker locks atthe wrong point;Open and close the loopto re-lock.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 27 / 31
Phase Tracking and Chromaticity Measurement
Close the loop at −45 s;Slow settling at low gain,faster as the gain israised;Chromaticity scan with10 Hz steps;Return step of 40 Hz istoo large, tracker locks atthe wrong point;Open and close the loopto re-lock.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 27 / 31
Phase Tracking and Chromaticity Measurement
Close the loop at −45 s;Slow settling at low gain,faster as the gain israised;Chromaticity scan with10 Hz steps;Return step of 40 Hz istoo large, tracker locks atthe wrong point;Open and close the loopto re-lock.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 27 / 31
Phase Tracking and Chromaticity Measurement
Close the loop at −45 s;Slow settling at low gain,faster as the gain israised;Chromaticity scan with10 Hz steps;Return step of 40 Hz istoo large, tracker locks atthe wrong point;Open and close the loopto re-lock.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 27 / 31
Fast Phase Tracking
Time (turns)
Fra
ctio
na
l fr
eq
ue
ncy
Fast tune tracking (200 turns decimation), 4096 turn FFT
1 2 3 4 5 6 7 8 9
x 104
0.38
0.381
0.382
0.383
0.384
0.385
0.386
0.387
0.388
0.389
0.39
Decimation factor in phasetracker controls trackingbandwidth;200 turns decimaton, 1.77 kHzmeasurement bandwidth;180 Hz closed loop trackingbandwidth;Use time-domaindownconversion to betterresolve tune modulation;Spectrum shows lines at 10and 50 hertz.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 28 / 31
Fast Phase Tracking
Time (turns)
Fra
ctio
na
l fr
eq
ue
ncy
Fast tune tracking (200 turns decimation), 4096 turn FFT
1 2 3 4 5 6 7 8 9
x 104
0.38
0.381
0.382
0.383
0.384
0.385
0.386
0.387
0.388
0.389
0.39
Decimation factor in phasetracker controls trackingbandwidth;200 turns decimaton, 1.77 kHzmeasurement bandwidth;180 Hz closed loop trackingbandwidth;Use time-domaindownconversion to betterresolve tune modulation;Spectrum shows lines at 10and 50 hertz.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 28 / 31
Fast Phase Tracking
Time (turns)
Fra
ctio
na
l fr
eq
ue
ncy
Fast tune tracking (200 turns decimation), 4096 turn FFT
1 2 3 4 5 6 7 8 9
x 104
0.38
0.381
0.382
0.383
0.384
0.385
0.386
0.387
0.388
0.389
0.39
Decimation factor in phasetracker controls trackingbandwidth;200 turns decimaton, 1.77 kHzmeasurement bandwidth;180 Hz closed loop trackingbandwidth;Use time-domaindownconversion to betterresolve tune modulation;Spectrum shows lines at 10and 50 hertz.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 28 / 31
Fast Phase Tracking
0 50 100 150 200 250 3000.8
0.9
1
1.1
1.2
Time (ms)
Am
plit
ude (
AD
C c
ounts
)
Fast tune tracking: amplitude
0 50 100 150 200 250 300−600
−400
−200
0
200
Time (ms)
Phase (
deg)
Phase
0 50 100 150 200 250 3000.3826
0.3828
0.383
0.3832
0.3834
0.3836
Time (ms)
Fra
ctional fr
equency
Tracking frequency vs. time
Decimation factor in phasetracker controls trackingbandwidth;200 turns decimaton, 1.77 kHzmeasurement bandwidth;180 Hz closed loop trackingbandwidth;Use time-domaindownconversion to betterresolve tune modulation;Spectrum shows lines at 10and 50 hertz.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 28 / 31
Fast Phase Tracking
100
101
102
103
10−3
10−2
10−1
100
101
102
103
104
105
Frequency (Hz)
Ma
gn
itu
de
(a
rb.
un
its)
FFT of tune frequency signal
Decimation factor in phasetracker controls trackingbandwidth;200 turns decimaton, 1.77 kHzmeasurement bandwidth;180 Hz closed loop trackingbandwidth;Use time-domaindownconversion to betterresolve tune modulation;Spectrum shows lines at 10and 50 hertz.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 28 / 31
Tune Variation
0 50 100 150 200 250 3000.8
0.9
1
1.1
1.2
Time (ms)
Am
plit
ud
e (
AD
C c
ou
nts
)
Fast tune tracking: amplitude
0 50 100 150 200 250 300−600
−400
−200
0
200
Time (ms)
Ph
ase
(d
eg
)
Phase
0 50 100 150 200 250 3000.3826
0.3828
0.383
0.3832
0.3834
0.3836
Time (ms)
Fra
ctio
na
l fr
eq
ue
ncy
Tracking frequency vs. time
Tune moves around by 5 × 10−4;Fitting complex phase spacetrajectories fails due to tunemodulation;Modal scan runs at 2 Hz andaliases the modulation;Grow/damp transient shows tuneshifts around 100 Hz (2.8 × 10−4)at 100 mA;At 15 mA expect only 4.2 × 10−5,completely obscured by thisbaseline modulation.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 29 / 31
Tune Variation
0 5 10 15 20 252.2
2.25
2.3
2.35
2.4
2.45
2.5
2.55x 10
4
Time (ms)
Magnitude (
arb
. units)
Mode −1
0 5 10 15 20 25120
140
160
180
200
220
Time (ms)
Phase (
degre
es)
Tune moves around by 5 × 10−4;Fitting complex phase spacetrajectories fails due to tunemodulation;Modal scan runs at 2 Hz andaliases the modulation;Grow/damp transient shows tuneshifts around 100 Hz (2.8 × 10−4)at 100 mA;At 15 mA expect only 4.2 × 10−5,completely obscured by thisbaseline modulation.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 29 / 31
Tune Variation
0 200 400 600 800 10000.3885
0.3886
0.3887
0.3888
0.3889
0.389
0.3891
Mode number
Fra
ctional tu
ne
Tune moves around by 5 × 10−4;Fitting complex phase spacetrajectories fails due to tunemodulation;Modal scan runs at 2 Hz andaliases the modulation;Grow/damp transient shows tuneshifts around 100 Hz (2.8 × 10−4)at 100 mA;At 15 mA expect only 4.2 × 10−5,completely obscured by thisbaseline modulation.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 29 / 31
Tune Variation
Tune moves around by 5 × 10−4;Fitting complex phase spacetrajectories fails due to tunemodulation;Modal scan runs at 2 Hz andaliases the modulation;Grow/damp transient shows tuneshifts around 100 Hz (2.8 × 10−4)at 100 mA;At 15 mA expect only 4.2 × 10−5,completely obscured by thisbaseline modulation.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 29 / 31
Tune Variation
0 200 400 600 800 10000.3885
0.3886
0.3887
0.3888
0.3889
0.389
0.3891
Mode number
Fra
ctional tu
ne
Tune moves around by 5 × 10−4;Fitting complex phase spacetrajectories fails due to tunemodulation;Modal scan runs at 2 Hz andaliases the modulation;Grow/damp transient shows tuneshifts around 100 Hz (2.8 × 10−4)at 100 mA;At 15 mA expect only 4.2 × 10−5,completely obscured by thisbaseline modulation.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 29 / 31
Injection Transient
−500 0 500−250
−200
−150
−100
−50
0
50
100
150
Bunch number (0 − single)
∆Y
(µ
m)
First turn displacements during injection
Before
After
Captured beam transient dueto the injection kickers firing;Automatic extraction of thedifference orbit;Converted to physical unitsusing bunch-by-bunchcurrents and measuredcalibration factor.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 30 / 31
Injection Transient
−500 0 500−250
−200
−150
−100
−50
0
50
100
150
Bunch number (0 − single)
∆Y
(µ
m)
First turn displacements during injection
Before
After
Captured beam transient dueto the injection kickers firing;Automatic extraction of thedifference orbit;Converted to physical unitsusing bunch-by-bunchcurrents and measuredcalibration factor.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 30 / 31
Injection Transient
−500 0 500−250
−200
−150
−100
−50
0
50
100
150
Bunch number (0 − single)
∆Y
(µ
m)
First turn displacements during injection
Before
After
Captured beam transient dueto the injection kickers firing;Automatic extraction of thedifference orbit;Converted to physical unitsusing bunch-by-bunchcurrents and measuredcalibration factor.
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 30 / 31
Summary
Successfully operated Dimtel bunch-by-bunch system in theESRF;Many diagnostic features have been demonstrated;In the demo setup feedback pushes vertical emittance from7.7 to 8 pm.With some balancing and optimization much lower noise floor iseasily achievable.I’d like to thank everyone who helped to make this a successfultest!
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 31 / 31
Summary
Successfully operated Dimtel bunch-by-bunch system in theESRF;Many diagnostic features have been demonstrated;In the demo setup feedback pushes vertical emittance from7.7 to 8 pm.With some balancing and optimization much lower noise floor iseasily achievable.I’d like to thank everyone who helped to make this a successfultest!
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 31 / 31
Summary
Successfully operated Dimtel bunch-by-bunch system in theESRF;Many diagnostic features have been demonstrated;In the demo setup feedback pushes vertical emittance from7.7 to 8 pm.With some balancing and optimization much lower noise floor iseasily achievable.I’d like to thank everyone who helped to make this a successfultest!
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 31 / 31
Summary
Successfully operated Dimtel bunch-by-bunch system in theESRF;Many diagnostic features have been demonstrated;In the demo setup feedback pushes vertical emittance from7.7 to 8 pm.With some balancing and optimization much lower noise floor iseasily achievable.I’d like to thank everyone who helped to make this a successfultest!
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 31 / 31
Summary
Successfully operated Dimtel bunch-by-bunch system in theESRF;Many diagnostic features have been demonstrated;In the demo setup feedback pushes vertical emittance from7.7 to 8 pm.With some balancing and optimization much lower noise floor iseasily achievable.I’d like to thank everyone who helped to make this a successfultest!
(Dimtel) BxB feedback and diagnostics in ESRF 2017-04-26 31 / 31