1. 12.4: SRF HOM Diagnostics: Experimental Results and Future Plans
Nicoleta Baboi*, Liangliang Shi*# *DESY; #UMAN
for the HOM-team
EuCARD2 WP12 Meeting
16 April 2014, Saclay

2. Aim HOM-based beam diagnostics for the European XFEL (E-XFEL)
Beam phase (wrt RF) and position
In 3.9 GHz and 1.3 GHz cavities
Strong interconnection to the FLASH linac
Benefits
Reduction in emittance dilution from transverse wakefields by centering beam in accelerating cavities
Direct, on-line measurement of beam phase wrt RF phase
Additional beam position monitoring

3. Contents Introduction HOM-based beam position monitoring
Principle
The European XFEL and FLASH
Overview of HOM-based diagnostics
HOM-based beam position monitoring
for 1.3GHz cavities
for 3.9GHz cavities
HOM-based beam phase monitoring
[for 3.9GHz cavities]
Partial summary
Stability study → Liangliang Shi

4. Principle Filter higher dipole mode for beam position
Filter higher monopole mode for beam phase ×
Beam offset [mm]
Phase difference

5. The European XFEL accelerating structures experimental hall undulators

6. FLASH

7. Accelerating Cavities for the E-XFEL and FLASH
The 1st dipole band
HOMBPM
The 2nd dipole band
The 1st dipole band
Coupled cavities

8. Status and Plans for HOM-based Beam Position Monitoring (HOM-BPM)
FLASH
E-XFEL
1.3 GHz Cavities
Electronics installed in 40 cavities (SLAC/CEA/DESY)
Raw signals used for beam centering
EuCARD2: Unstable calibration
started stability studies (L. Shi’s talk)
Electronics designed and tested in lab, based on same frequency as for FLASH (WUT/DESY)
Next to be tested with beam
3.9 GHz Cavities
Theoretical and experimental studies (EuCARD + FNAL)
Defined specs for HOM-BPM electronics (also for E-XFEL)
Electronics built by FNAL, installed (Mar. 2014); to be tested with beam; serves as prototype for E-XFEL
EuCARD2: Unstable calibration (same problem as for 1.3 GHz?)
To add to stability study for 1.3
Electronics under design, based on same frequency ranges as for FLASH (DESY)
But much more challenging:
8 coupled cavities cf. 4
4.5 cf 1 MHz bunch frequency
Different orientation of cavities
EuCARD2: Need significant theoretical and experimental studies (next talks)
FLASH
E-XFEL
1.3 GHz Cavities
Proof-Of-Principle made (SLAC/CEA/DESY)
Tests for E-XFEL to be made in FLASH
Electronics designed and tested in lab (same electronics as for E-XFEL HOM-BPM, WUT/DESY)
To be tested in FLASH
EuCARD2: experimental studies
3.9 GHz Cavities
So far no isolated monopole mode identified, which could be used for phase monitoring
Theoretical (and experimental) studies (lower priority in EuCARD2)
Same as for FLASH
It would be nice to have only one overview page (with previous); if you have an idea…

9. Status and Plans for HOM-based Beam Phase Monitoring
FLASH
E-XFEL
1.3 GHz Cavities
Electronics installed in 40 cavities (SLAC/CEA/DESY)
Raw signals used for beam centering
EuCARD2: Unstable calibration (phase or even frequency drifts?)
started stability studies (L. Shi)
Electronics designed and tested in lab, based on same frequency as for FLASH (WUT/DESY)
3.9 GHz Cavities
Theoretical and experimental studies (EuCARD + FNAL)
Defined specs for HOM-BPM electronics (also for E-XFEL)
Electronics built by FNAL, installed (Mar. 2014); to be tested with beam; serves as prototype for E-XFEL
EuCARD2: Unstable calibration (same problem as for 1.3 GHz?)
To add to stability study for 1.3
Electronics under design, based on same frequency ranges as for FLASH (DESY)
But much more challenging:
8 coupled cavities cf. 4
4.5 cf 1 MHz bunch frequency
Different orientation of cavities
EuCARD2: Need significant theoretical and experimental studies (next talks)
FLASH
E-XFEL
1.3 GHz Cavities
Proof-Of-Principle made (SLAC/CEA/DESY)
Tests for E-XFEL to be made in FLASH
Electronics designed and tested in lab (same electronics as for E-XFEL HOM-BPM, WUT/DESY)
To be tested in FLASH
EuCARD2: experimental studies
3.9 GHz Cavities
So far no isolated monopole mode identified, which could be used for phase monitoring
Theoretical (and experimental) studies (lower priority in EuCARD2)
Same as for FLASH
It would be nice to have only one overview page (with previous); if you have an idea…

10. Status and Plans for HOM-BPM / 1.3 GHz cavities / FLASH
E-XFEL
1.3 GHz Cavities
Electronics installed in 40 cavities (SLAC/CEA/DESY; 2006)
Raw signals used for beam centering
EuCARD2: Unstable calibration
started stability studies (L. Shi’s talk)
Electronics designed and tested in lab, based on same frequency as for FLASH (WUT/DESY)
Next to be tested with beam
3.9 GHz Cavities
Theoretical and experimental studies (EuCARD + FNAL)
Defined specs for HOM-BPM electronics (also for E-XFEL)
Electronics built by FNAL, installed (Mar. 2014); to be tested with beam; serves as prototype for E-XFEL
EuCARD2: Unstable calibration (same problem as for 1.3 GHz?)
To add to stability study for 1.3
Electronics under design, based on same frequency ranges as for FLASH (DESY)
But much more challenging:
8 coupled cavities cf. 4
4.5 cf 1 MHz bunch frequency
Different orientation of cavities
EuCARD2: Need significant theoretical and experimental studies (next talks)
FLASH
E-XFEL
1.3 GHz Cavities
Proof-Of-Principle made (SLAC/CEA/DESY)
Tests for E-XFEL to be made in FLASH
Electronics designed and tested in lab (same electronics as for E-XFEL HOM-BPM, WUT/DESY)
To be tested in FLASH
EuCARD2: experimental studies
3.9 GHz Cavities
So far no isolated monopole mode identified, which could be used for phase monitoring
Theoretical (and experimental) studies (lower priority in EuCARD2)
Same as for FLASH
Past experience / Achieved past year / Under work / EuCARD-2 challenges

11. Status and Plans for HOM-BPM / 1.3 GHz cavities / E-XFEL
FLASH
E-XFEL
1.3 GHz Cavities
Electronics installed in 40 cavities (SLAC/CEA/DESY; 2006)
Raw signals used for beam centering
EuCARD2: Unstable calibration
started stability studies (L. Shi’s talk)
Electronics designed and tested in lab, based on same frequency as for FLASH (WUT/DESY)
Next to be tested with beam
3.9 GHz Cavities
Theoretical and experimental studies (EuCARD + FNAL)
Defined specs for HOM-BPM electronics (also for E-XFEL)
Electronics built by FNAL, installed (Mar. 2014); to be tested with beam; serves as prototype for E-XFEL
EuCARD2: Unstable calibration (same problem as for 1.3 GHz?)
To add to stability study for 1.3
Electronics under design, based on same frequency ranges as for FLASH (DESY)
But much more challenging:
8 coupled cavities cf. 4
4.5 cf 1 MHz bunch frequency
Different orientation of cavities
EuCARD2: Need significant theoretical and experimental studies (next talks)
FLASH
E-XFEL
1.3 GHz Cavities
Proof-Of-Principle made (SLAC/CEA/DESY)
Tests for E-XFEL to be made in FLASH
Electronics designed and tested in lab (same electronics as for E-XFEL HOM-BPM, WUT/DESY)
To be tested in FLASH
EuCARD2: experimental studies
3.9 GHz Cavities
So far no isolated monopole mode identified, which could be used for phase monitoring
Theoretical (and experimental) studies (lower priority in EuCARD2)
Same as for FLASH
Past experience / Achieved past year / Under work / EuCARD-2 challenges

12. HOM-BPM / 1.3 GHz cavities / E-XFEL: Electronics Designed and Tested in Lab
Single channel:
Direct sampling of all three frequencies without any downconversion
mTCA standard
RTM side AMC side
Samer Bou-Habib, WUT, DESY

13. HOM-BPM / 1.3 GHz cavities / E-XFEL: Electronics Designed and Tested in Lab (2)
System architecture
8 channels
Samer Bou-Habib, WUT, DESY
RTM side AMC side
DRTM-HOM
DAMC-DS800
RF1 ..
RF8
REF (RF-backplane)
REF FP 6 8
CLK
+Distribution
CLK out

14. HOM-BPM / 1.3 GHz cavities / E-XFEL: Electronics Designed and Tested in Lab (3)
Filter test board
two filters, one on each side
each for 3 frequencies (1.3/1.7/2.4)
Example measurement
Attenuation settings: GHz, 1.7 GHz,
The filter should be tuned and then implemented in an 8 channel RTM
RF1 ..
RF8
REF (RF-backplane)
REF FP 6 8
CLK
+Distribution
CLK out
DRTM-HOM

15. Status and Plans for HOM-BPM / 3.9 GHz cavities / FLASH
E-XFEL
1.3 GHz Cavities
Electronics installed in 40 cavities (SLAC/CEA/DESY)
Raw signals used for beam centering
EuCARD2: Unstable calibration
started stability studies (L. Shi)
Electronics designed and tested in lab, based on same frequency as for FLASH (WUT/DESY)
Next to be tested with beam
3.9 GHz Cavities
Theoretical and experimental studies (EuCARD + FNAL)
Defined specs for HOM-BPM electronics (also for E-XFEL)
Electronics built by FNAL, installed (Mar. 2014); to be tested with beam; serves as prototype for E-XFEL
EuCARD2: Unstable calibration (same problem as for 1.3 GHz?)
Will add to stability study for 1.3
Electronics under design, based on same frequency ranges as for FLASH (DESY)
But much more challenging:
8 coupled cavities cf. 4
4.5 cf 1 MHz bunch frequency
Different orientation of cavities
EuCARD2: Need significant theoretical and experimental studies (next talks)
FLASH
E-XFEL
1.3 GHz Cavities
Proof-Of-Principle made (SLAC/CEA/DESY)
Tests for E-XFEL to be made in FLASH
Electronics designed and tested in lab (same electronics as for E-XFEL HOM-BPM, WUT/DESY)
To be tested in FLASH
EuCARD2: experimental studies
3.9 GHz Cavities
So far no isolated monopole mode identified, which could be used for phase monitoring
Theoretical (and experimental) studies (lower priority in EuCARD2)
Same as for FLASH
It would be nice to have only one overview page (with previous); if you have an idea…
Past experience / Achieved past year / Under work / EuCARD-2 challenges

16. HOM-BPM / 3.9 GHz cavities / FLASH: Electronics from FNAL Installed
Nathan Eddy, FNAL
Bandpass Filter ~5.43 GHz or 9.06 GHz 100 MHz BW
Mixer
uTCA Digitizer
SIS8300
(108MS/sec) LO
30 MHz IF

17. HOM-BPM / 3.9 GHz cavities / FLASH: 5GHz Downconverter and PLL Boards
Nathan Eddy, FNAL

18. HOM-BPM / 3.9 GHz cavities / FLASH: First Beam signals on scope
5 GHz (C1H2)
9 GHz (C1H1)
Signals from 9 bunches

19. HOM-BPM / 3.9 GHz cavities / FLASH: Raw ADC Signals in DOOCS
Each plot: signal from one HOM coupler
Signals from 2 bunches

20. Status and Plans for HOM-BPM / 3.9 GHz cavities / E-XFEL
FLASH
E-XFEL
1.3 GHz Cavities
Electronics installed in 40 cavities (SLAC/CEA/DESY)
Raw signals used for beam centering
EuCARD2: Unstable calibration
started stability studies (L. Shi)
Electronics designed and tested in lab, based on same frequency as for FLASH (WUT/DESY)
Next to be tested with beam
3.9 GHz Cavities
Theoretical and experimental studies (EuCARD + FNAL)
Defined specs for HOM-BPM electronics (also for E-XFEL)
Electronics built by FNAL, installed (Mar. 2014); to be tested with beam; serves as prototype for E-XFEL
EuCARD2: Unstable calibration (same problem as for 1.3 GHz?)
To add to stability study for 1.3
Electronics under design, based on same frequency ranges as for FLASH (DESY)
But much more challenging:
8 coupled cavities cf. 4
4.5 cf 1 MHz bunch frequency
Different orientation of cavities
EuCARD2: Need significant theoretical and experimental studies (next talks)
FLASH
E-XFEL
1.3 GHz Cavities
Proof-Of-Principle made (SLAC/CEA/DESY)
Tests for E-XFEL to be made in FLASH
Electronics designed and tested in lab (same electronics as for E-XFEL HOM-BPM, WUT/DESY)
To be tested in FLASH
EuCARD2: experimental studies
3.9 GHz Cavities
So far no isolated monopole mode identified, which could be used for phase monitoring
Theoretical (and experimental) studies (lower priority in EuCARD2)
Same as for FLASH
It would be nice to have only one overview page (with previous); if you have an idea…
Past experience / Achieved past year / Under work / EuCARD-2 challenges

21. Bandpass Filter ~5.43 GHz or 9.06 GHz 100 MHz BW
HOM-BPM / 3.9 GHz cavities / E-XFEL: Design of 5 GHz Down-converter ready
Bandpass Filter ~5.43 GHz or 9.06 GHz 100 MHz BW
Mixer
uTCA Digitizer
SIS8300
(108MS/sec) LO
30 MHz IF
Thomas Wamsat, DESY

22. HOM-BPM / 3.9 GHz cavities / E-XFEL: Design of 5 GHz PLL ready
Thomas Wamsat, DESY
Design of 9 GHz DCW and PLL under work

23. Status and Plans for HOM-PhMon / 1.3 GHz cavities
FLASH
E-XFEL
1.3 GHz Cavities
Electronics installed in 40 cavities (SLAC/CEA/DESY)
Raw signals used for beam centering
EuCARD2: Unstable calibration (phase or even frequency drifts?)
started stability studies (L. Shi)
Electronics designed and tested in lab, based on same frequency as for FLASH (WUT/DESY)
3.9 GHz Cavities
Theoretical and experimental studies (EuCARD + FNAL)
Defined specs for HOM-BPM electronics (also for E-XFEL)
Electronics built by FNAL, installed (Mar. 2014); to be tested with beam; serves as prototype for E-XFEL
EuCARD2: Unstable calibration (same problem as for 1.3 GHz?)
To add to stability study for 1.3
Electronics under design, based on same frequency ranges as for FLASH (DESY)
But much more challenging:
8 coupled cavities cf. 4
4.5 cf 1 MHz bunch frequency
Different orientation of cavities
EuCARD2: Need significant theoretical and experimental studies (next talks)
FLASH
E-XFEL
1.3 GHz Cavities
Proof-Of-Principle made (SLAC/CEA/DESY)
Tests for E-XFEL to be made in FLASH
Electronics designed and tested in lab (same electronics as for E-XFEL HOM-BPM, WUT/DESY)
To be tested in FLASH
EuCARD2: experimental studies
3.9 GHz Cavities
So far no isolated monopole mode identified, which could be used for phase monitoring
Theoretical (and experimental) studies (lower priority in EuCARD2)
Same as for FLASH
It would be nice to have only one overview page (with previous); if you have an idea…
Past experience / Achieved past year / Under work / EuCARD-2 challenges

24. HOM-PhMon / 1.3 GHz cavities / E-XFEL: Electronics Designed and Tested in Lab
Same as electronics as presented for HOM-BPM / 1.3GHz
RTM side AMC side
Samer Bou-Habib, WUT, DESY

25. Status and Plans for HOM-based Beam Phase Monitoring
FLASH
E-XFEL
1.3 GHz Cavities
Electronics installed in 40 cavities (SLAC/CEA/DESY)
Raw signals used for beam centering
EuCARD2: Unstable calibration (phase or even frequency drifts?)
started stability studies (L. Shi)
Electronics designed and tested in lab, based on same frequency as for FLASH (WUT/DESY)
3.9 GHz Cavities
Theoretical and experimental studies (EuCARD + FNAL)
Defined specs for HOM-BPM electronics (also for E-XFEL)
Electronics built by FNAL, installed (Mar. 2014); to be tested with beam; serves as prototype for E-XFEL
EuCARD2: Unstable calibration (same problem as for 1.3 GHz?)
To add to stability study for 1.3
Electronics under design, based on same frequency ranges as for FLASH (DESY)
But much more challenging:
8 coupled cavities cf. 4
4.5 cf 1 MHz bunch frequency
Different orientation of cavities
EuCARD2: Need significant theoretical and experimental studies (next talks)
FLASH
E-XFEL
1.3 GHz Cavities
Proof-Of-Principle made (SLAC/CEA/DESY)
Tests for E-XFEL to be made in FLASH
Electronics designed and tested in lab (same electronics as for E-XFEL HOM-BPM, WUT/DESY)
To be tested in FLASH
EuCARD2: experimental studies
3.9 GHz Cavities
So far no isolated monopole mode identified, which could be used for phase monitoring
Theoretical (and experimental) studies (low priority in EuCARD2)
Same as for FLASH
It would be nice to have only one overview page (with previous); if you have an idea…
Past experience / Achieved past year / Under work / EuCARD-2 challenges

26. 1st Deliverable Approaching
Report on the design of electronics for XFEL-HOM diagnostics (M18)
Good progress:
1.3GHz cavities
design ready
tests to be made with beam
3.9GHz cavities
Design for 5GHz channels ready
1st boards should be ready in May and then tested in lab
Design of 9GHz channels will follow

27. Summary of Part 1 HOM-based BPMs HOM-based phase monitoring
for 1.3GHz cavities:
prev. experience with electronics at FLASH
Design of electronics for the XFEL finished -> 1st milestone
Next: Tests with beam
for 3.9GHz cavities
FNAL electronics installed at FLASH
E-XFEL electronics: design in advanced stage -> 1st milestone
Next: Tests in lab and with beam
HOM-based phase monitoring
for 1.3GHz cavities
Not for 3.9GHz cavities
Part 2: Stability study → Liangliang Shi

28. Part 2: Liangliang Shi FLASH E-XFEL 1.3 GHz Cavities
Electronics installed in 40 cavities (SLAC/CEA/DESY; 2006)
Raw signals used for beam centering
EuCARD2: Unstable calibration
started stability studies (L. Shi’s talk)
Electronics designed and tested in lab, based on same frequency as for FLASH (WUT/DESY)
Next to be tested with beam
3.9 GHz Cavities
Theoretical and experimental studies (EuCARD + FNAL)
Defined specs for HOM-BPM electronics (also for E-XFEL)
Electronics built by FNAL, installed (Mar. 2014); to be tested with beam; serves as prototype for E-XFEL
EuCARD2: Unstable calibration (same problem as for 1.3 GHz?)
Will add to stability study for 1.3
Electronics under design, based on same frequency ranges as for FLASH (DESY)
But much more challenging:
8 coupled cavities cf. 4
4.5 cf 1 MHz bunch frequency
Different orientation of cavities
EuCARD2: Need significant theoretical and experimental studies (next talks)
FLASH
E-XFEL
1.3 GHz Cavities
Proof-Of-Principle made (SLAC/CEA/DESY)
Tests for E-XFEL to be made in FLASH
Electronics designed and tested in lab (same electronics as for E-XFEL HOM-BPM, WUT/DESY)
To be tested in FLASH
EuCARD2: experimental studies
3.9 GHz Cavities
So far no isolated monopole mode identified, which could be used for phase monitoring
Theoretical (and experimental) studies (lower priority in EuCARD2)
Same as for FLASH
Past experience / Achieved past year / Under work / EuCARD-2 challenges

29. Thank you!

30. Reserve Slides:

31. Subtask 10.5.1 Two Choices for HOMBPM Electronics
Localized modes
9060 MHz
Coupled modes
5437 MHz
“Common position” of power minimum
Integrated power
RMS Error at Module Center
Pei Zhang

32. Specs for Final Electronics for FLASH defined
Based on EuCARD work, specs defined for HOMBPM electronics for
FLASH
The European XFEL
More research necessary, since there will be 8 cavities in 3.9 GHz module (EuCARD2, incl. 1.3 GHz cavities)
Position type
Resolution
# of channels
Local position in the cavity
~ μm
6 HOM couplers
Global position over the module
~ μm
2 HOM couplers
Bandpass Filter ~5.43 GHz or 9.06 GHz 100 MHz BW
Mixer
uTCA Digitizer
SIS8300
(108MS/sec) LO
30 MHz IF
Brian Fellenz, Nathan Eddy, Fermilab

33. HOMSC12, Cockcroft Institute, Jun 26th, 2012
Challenges
Dipole beam-pipe modes
The 1st and 2nd dipole band
The 5th dipole band
Fundamental band
Large R/Q’s
Modes propagate
Pei Zhang
HOMSC12, Cockcroft Institute, Jun 26th, 2012
Page 33

34. Electronics for 3.9GHz/FLASH from FNAL: Design
CAN BUS CONTROLLER
BOARD
CAN I/O
5 GHz PLL
9 GHz PLL
BPF
9GHz DOWNCONVERTERS
[30 MHz OUT]
5 GHz
DOWNCONVERTERS
[30MHz OUT]
5 GHz & 9GHz
[30 MHz OUT]
81MHz
INPUTS
9 GHz DC
5 GHz DC
4-WAY
SPLITTER
8-WAY
IN 1
IN 2
IN 3
IN 4
IN 5
IN 6 IN
FOR PHASE MEASUREMENTS
P. S.
+15V
+7V
9GHz 5GHz
LO MON.
OUT

35. 5GHz Downconverter Board from FNAL
ATTEN
5-Bits
0-31 dB
30MHz BPF
BW: 15MHz
40MHz LPF
-20 dB
36 dB GAIN
+7V
IF Mon.
Output
30 MHz
14 dB RF
Monitor
-10 dB
RF DET.
19 dB
18 dB LO
INPUT
MON
I MON
-2 dB
GAIN
CTRL

36. 9GHz Downconverter Board from FNAL
ATTEN
5-Bits
0-31 dB
30MHz BPF
BW: 15MHz
40MHz LPF
-6 dB
36 dB GAIN
+7V
IF Mon.
Output
30 MHz
19 dB RF
Monitor
-20 dB
-10 dB
RF DET.
18 dB LO
INPUT
MON
I MON

37. 5GHz PLL Board from FNAL REF 81MHz BPF BW: 7MHz LOOP FILTER 3 dB +7V
OUTPUT
+8 dBm
15 dB
2-WAY
SPLITTER
Output
81.25 MHz
SCK
RSTB
SDI
SEN
SDO CP RF
HMC702LP6CE
PLL
HMC430LP4
VCO
+15V
16dB
TEST CONNECTOR