1. CERN’s PS Complex LLRF consolidation:
technology, beam results & plans
Maria Elena Angoletta, CERN BE/RF
A. Blas, A. Findlay, J. Sanchez-Quesada, A. Butterworth, J. Molendijk, F. Pedersen, M. Schokker, P. Leinonen
+ previous team members
RFTech workshop, PSI, 2-3 Dec 2010

2. Outline CPS LLRF consolidation overview LEIR LLRF
PSB LLRF consolidation
Conclusions
References
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” 1/29

3. Outline CPS LLRF consolidation overview LEIR LLRF
PSB LLRF consolidation
Conclusions
References
Scope & machine features
Why, what & how
Roadmap
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” 2/29

4. 1. CPS LLRF consolidation: scope
CERN’s PS Complex (CPS) synchrotrons: LEIR, PSB, PS, AD.
Possible future machine: ELENA.
Request to improve injector complex & to keep it running for 25 years [1,2]
→ high-level + low-level RF renovation
Two LLRF
~ fixed fREV, high-frequency cavities systems: LHC, LINAC4
fREV swing, low-frequency cavities, …. → THIS TALK
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” 3/29

5. 1. CPS LLRF consolidation : machines features
Often wide fREV swing (injection→extraction)
Mostly low-frequency cavities (few MHz).
Large synchrotron tunes (up to a few kHz).
High dynamic range in cavity control voltages (sometimes > 80 dB !!!)
PS machine, cycle NOMINAL (ions), batch expansion + bunch splitting
Full cycle-to-cycle behaviour. Also varied parameters (ex: intensity) for same cycle.
Varied RF gymnastics & cavities combinations
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” 4/29

6. 1. CPS LLRF consolidation: why
Hardware obsolescence (modules from ‘70s) + variety
Already-stretched modules capabilities
Limited remote/cycle-to-cycle/in-cycle control capabilities
Limited archiving capabilities (local knobs)
New requirements:
Linac4→PSB injection,
Also potential new machine: ELENA.
LLRF renovation aims:
To ease machine operation
To reduce maintenance effort
To improve overall performance + reproducibility
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” 5/29

7. 1. CPS LLRF consolidation: what
Frequency program from Btrain pulses (BUP, BDOWN)
Beam phase + radial loops
Radial/frequency steering
Synchronisation loop @extraction
Bunch shaping, blowup
RF gymnastics
RF trains generation
Amplitude/phase voltage loops
Tuning loops
Cavity gap control + interlocks.
BEAM DYNAMICS PLAYS IMPORTANT ROLE
Example: LLRF actions required by LEIR
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” 6/29

8. 1. CPS LLRF consolidation: how
Digital technology !
Most frequent choice nowadays [3,4]
Full/remote configurability + control + data acquisition
Sophisticated/powerful data processing + signal generation
Main features:
Modular approach (s/w + h/w) + accessibility (no black box!)
Flexibility + adaptability to different machines
Hardware main blocks:
VME motherboard [5,6]
Daughtercards : MDDS, 4-ch DDC (ADC), 4-ch. SDDS (DAC)
Tagged clock [7] for system-wide phase synchronisation .
I/Q acquisition & control; typically RF freq. direct sampling.
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” 7/29

9. 1. CPS LLRF consolidation: roadmap
: studies on PSB beams for LEIR LLRF (pilot project) [8,9].
Devised digital technology & main concepts.
CNAO adapts same technology to CNAO custom h/w [10].
2006: LEIR LLRF phase 1 commissioned [11]
2006/08: Proposals for AD consolidation [12], ELENA [13], PS tests [14].
2008: PSB LLRF renovation project started [15].
2009: LEIR LLRF fully commissioned & integrated [16].
Rest of this talk
2010: Started collaboration with MedAustron on LLRF + HLRF.
Q4 2011: 1 ring PSB system equipped (for tests) with new h/w.
>= 2013: 4 PSB rings equipped & commissioned..
> 2015: consolidation plan to be finalised.
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” 8/29

10. Outline CPS LLRF consolidation overview LEIR LLRF
PSB LLRF consolidation
Conclusions
References
LEIR Synchrotron
Overview
Main h/w blocks
Beam results
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” 9/29

11. 2. LEIR LLRF: synchrotron
LEIR: Low-Energy Ion Ring [17]
PB54+ ions (now), lighter ions (future).
One cavity:
Magnetic alloy-based (Finemet® FT3M)
Wide-band [ MHz], up to 4 kV, non-tunable [18].
LEIR machine layout
LEIR main parameters for Pb54+
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” /29

12. 2. LEIR LLRF: overview
Important “per se” & as LLRF consolidation pilot project.
Happy LEIR LLRF users
First all-digital LLRF for CERN synchrotron
Big RF group investment (manpower)
Success! Reliable, powerful, flexible
(LEIR operation runs 2006, 2007, 2009, 2010).
Frequency program
Radial loop (h = 1 & h = 2)
Phase loop (h = 1 & h = 2)
Synchro loop (h = 1 & h = 2)
RF trains generation
Double harmonic operation
Cavity phase & voltage loops
Cavity gap operation
Acceleration + bunch-shaping (dual-harmonic operation on same cavity ).
No black box: fully configurable & observable system.
Features
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” /29

13. 2. LEIR LLRF: overview (layout)
Keys: MDDS – Master Direct Digital Synthesiser (DDS); SDDS - Slave DDS; DDC – Digital Down Converter; CCI – Cavity Control Interface; TCF – Tagged Clock Fanout; TPU –Transversal Pick-Up; CTRV – Timing Receiver Module; PPC – Power PC; Bup, Bdown – measured magnetic field.
Blue modules: produced by and under the responsibility of RF group.
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” /29

14. 2. LEIR LLRF: overview (operation)
Working Set
OASIS (data visualisation)
Function editor
Tomoscope
RF Synoptic
CONTROL
Cavity control
LLRF
LOCAL CR
Next slides
PLC
RF trains to: transverse damper, tomoscope, tune meas
2x radial PUs (Σ+Δ), Phase PU, BTrain, extraction synchro ref.
HLRF
RING
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” /29

15. 2. LEIR LLRF: main h/w blocks
DSP-carrier [3,4] :
Function: beam ctrl, carries daughtercards, s/w int’face, diagnostics...
6U VME64x, ADSP21160M DSP, 8 MB memory, FPGAs (glue-logic & light processing).
Inter-DSP data exchange via linkports™.
Master Direct Digital Synthesiser:
Function: tagged clock [7] (single/double) generation.
AD GHz DDS + Stratix.
LVDS + Firewire connector & cables.
In-cycle change of MDDS clock h to cope with fREV swing.
MDDS daughtercard – schematic view.
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” /29

16. 2. LEIR LLRF: main h/w blocks (cont’d)
DDC daughtercard – schematic view.
Function: tunable RF receiver. CIC filter under DSP control.
ADC (AD9245, 14 bits, 80 MHz) + Stratix . SRAM (256 k x 16 bits).
Digital Down Converter (4 channels)
Digital I/O for cavity interfacing.
Slave Direct Digital Synthesiser (4 channels):
Function: analogue voltages generation (cavity voltages + RF trains).
DAC (AD9754, 14 bits, 125 MHz) + Stratix. SRAM (256 k x 16 bits).
Switched DAC Iref for high output dynamic range.
SDDS daughtercard – schematic view.
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” /29

17. 2. LEIR LLRF: beam results (synchro loop)
Aim: to synchronise in frequency+phase the beam to external ref.
Different synchro algorithms available & PPM-selectable.
Frequency steering
Extraction
Synchro phase loop closed
Frequency steering (7 ms)
Synchro phase loop
Frequency steering started
Extraction
Synchro phase loop closed
EARLY beam (Nov. 2007)
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” /29

18. 2. LEIR LLRF: beam results (cavity loop)
Aim: I/Q loop on cavity voltage.
Independent h = 1 & h = 2 loops.
Open loop cavity voltage response:
Pink = programmed voltage
Blue = measured voltage
Cavity servoloop response to 1.5 kV step.
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” /29

19. Outline CPS LLRF consolidation overview LEIR LLRF
PSB LLRF consolidation
Conclusions
References
Synchrotron
Renovation layout + technology
Hardware
Initial beam results
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” /29

20. 3. PSB LLRF: synchrotron 4 rings superimposed, protons.
One independent LLRF /ring.
Three HLRF /ring.
Ferrite-loaded, tunable, low-frequency cavities.
Include voltage & tuning loops.
Extremely varied cycle-to-cycle requests: intensity (109 to >1013 /ring), emittances, RF gymnastics …
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” /29

21. 3. PSB LLRF: consolidation
LLRF must satisfy present + new requirements
HLRF consolidation under study → LLRF design must be modular.
NB: LLRF tests/commissioning can be done in // with normal operation.
Option 1: ferrite cavities → tuning/voltage loops to LLRF (Phase 2).
Option 2: C02+C04 substituted by one Finemet® cavity (FT3L)
→ LLRF to implement voltage loops + cavity interfacing.
Layout + some modules shown in next slides
H/w + s/w development to improve capabilities & performances. Evolution of LEIR system.
Ambitious beam tests campaign to validate capabilities & approaches
2008, 2010, 2011: with LEIR-type hardware.
2011 onwards: with new hardware.
Roadmap
Some beam results shown in next slides
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” /29

22. 3. PSB LLRF: consolidation (layout)
Keys: MDDS – Master Direct Digital Synthesiser (DDS); DAC – RF gen. daughtercard; ADC – Acquisition daughtercard; TCF – Tagged Clock Fanout; TPU –Transversal Pick-Up; HLRF – High-Level RF; CTRV – Timing Receiver Module; MEN A20 – Master VME board; VXS Switch – Switch board for VXS crate; Bup,Bdown – measured B field.
Blue modules: produced by and under the responsibility of RF group.
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” /29

23. 3. PSB LLRF: consolidation (technology)
Same blocks/granularity as LEIR but more powerful technology.
Backplane: VME Switched Serial (VXS), Standard VITA 41.0
Fully backwards-compatible with VME
Switch module for inter-boards high-speed comms + data exchange ( up to Gbps).
Motherboard: (6U)
Powerful data processing: 2 x Virtex5 FPGAs + SharcDSP 400MHz
FPGA_FMC: FMC processing (CIC filters, RF generation, cavity interface…)
FPGA_MAIN + DSP: comms, beam control processing & diagnostics.
RF clock + tag distributed as separate lines to each motherboard.
FPGA Mezzanine Standard (FMC) I/O daughtercards
Only analogue front-end (no on-board data processing)
High pin count connector (400 pins)
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” /29

24. 3. PSB LLRF: consolidation h/w (FMC carrier)
FPGA for FMC data processing
SRAM clocked by RF clock
Inter-board communication via VXS bus (up to Gbps)
J. Molendijk main engineer
Communication with RTM board (timings & digital outputs)
FMC site
FPGA + DSP for communication, beam control processing & diagnostics
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” /29

25. 3. PSB LLRF: consolidation h/w (ADC FMC)
High pin count FMC connector
2 x AD9268 ADCs: double ADC chipset, 16bit, 125MSPS.
Offset compensation scheme + temperature compensated offset control.
Front panel essential also for thermal dissipation
Three-colors front-panel leds under FPGA_FMC control.
Picture (and work!) courtesy of J. Sanchez-Quesada
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” /29

26. 3. PSB LLRF: consolidation h/w (DAC FMC)
2 x AD9747: : double DAC chipset, 16bit, 250 MSPS
Programmable digital + analogue gains for dynamic range shift.
Unique PCB identification by silicon ID chip. On-board EEPROM to store h/w-specific info (FMC type, VN, operating voltage…)
Picture (and work!) courtesy of P. Leinonen
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” /29

27. I know what you’re thinking…
WOW!!!!
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” /29

28. 3. PSB LLRF: initial results (C04 phase servoing)
Aim: improved bunching factor.
How: C04 phase controlled by feedback w.r.t. C02 or beam phases (user-selectable).
Bunches after injection
(276 to 388 ctime):
Square shape
No “pedestal”
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” /29

29. 3. PSB LLRF: initial results (bunch splitting)
Aim: obtain beam with specific extraction.
Equal-height final bunches
(756 to 765 ctime)
Nice bunch splitting
(759 to 769 ctime)
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” /29

30. 4. Conclusions IT’S A DEMANDING & EXCITING TIME !!!
RF group has chosen to consolidate PS Complex LLRF systems
To reduce maintenance effort
To improve machine operation
→ ad-hoc LLRF family started for this
LEIR LLRF: successful pilot project
Reliable, powerful & flexible
Essential experience for PS Complex renovation
PSB LLRF consolidation: project started in 2008 & underway
Evolution of LEIR LLRF: h/w + s/ developments to improve performances
Ambitious beam tests campaign to validate capabilities & approaches
Precise consolidation plan for other machines to be finalised
IT’S A DEMANDING & EXCITING TIME !!!
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” /29

31. 5. References [1] [2] [3] [4] [5] [6] [7] [8] [9]
S. Baird, “Keeping The Present LHC Injector Complex Running for 25 Years”, Chamonix 2010.
G. Arduini et al., “Possible Improvements to the Existing Pre-Injector Complex in the Framework of Continued Consolidation”, Chamonix 2010.
M.E. Angoletta, “Digital Low-Level RF”, EPAC ’06, invited talk WEXPA03.
M.E. Angoletta, “Digital Signal Processing in beam Instrumentation: Latest Trends and Typical Applications”, DIPAC ’03, invited talk IT07.
M. E. Angoletta, “The DSP-Carrier Board Used By The LEIR Low-Level RF System: User’s Manual”, AB-Note RF.
M. E. Angoletta, “The LEIR LLRF DSP-Carrier Board: Performance, CPS Renovation Plan And Recommendations”, AB-Note RF.
R. Garoby, “Multi-Harmonic RF Source for the Anti-Proton Production Beam of the AD”, PS/RF/Note
M. E. Angoletta, J. H. DeLong (BNL), A. Findlay, F. Pedersen, “Feasibility Tests of a New All-Digital Beam Control Scheme for LEIR”, AB-Note RF.
M. E. Angoletta, J. Bento, A. Blas, J. H. Delong (BNL), A. Findlay, P. Matuszkiewicz, F. Pedersen, A. Salom-Sarasqueta, “Beam Tests of a New Digital Beam Control System for the CERN LEIR Accelerator”, PAC’05, Knoxville, USA.
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” 1/29

32. 5. References (cont’d) [10] [11] [12] [13] [14] [15] [16] [17]
M. E. Angoletta, A. Findlay (CERN), O. Bourrion, R. Foglio, D. Tourres, C. Vescovi (LPSC Genoble), L. Falbo, S. Hunt (CNAO), D. DeMartinis (INFN), “CERN PSB Beam Tests of CNAO Synchrotron’s Digital LLRF”, EPAC ‘08.
M. E. Angoletta, A. Findlay, “First Experience With The New LEIR Digital Beam Control System”, AB-Note RF.
T. Eriksson, “AD Consolidation for Operation Beyond 2010”, CERN-AB OP.
T. Eriksson et al. , “ELENA – a Preliminary Cost and Feasibility Study”, CERN-AB OP.
M.E. Angoletta, S. Hancock, F. Pedersen, M. Schokker, J.-L. Vallet, “Proposal for a Cavity Phase Observation System in the PS Machine”, AB-Note RF.
M. E. Angoletta, A. Blas, A. Butterworth, A. Findlay, P. M. Leinonen, J. C. Molendijk, F. Pedersen, J. Sanchez-Quesada, M. Schokker, “CERN’s PS Booster LLRF Renovation: Plans and Initial Beam Tests”, IPAC 2010.
M. E. Angoletta, J. Bento, A. Blas, E. Bracke, A. Butterworth, F. Dubouchet, A. Findlay, F. Pedersen, J. Sanchez-Quesada, “CERN’s LEIR Digital LLRF: System Overview and Operational Experience”, IPAC 2010.
M. Chanel et al., “LEIR: Towards the Nominal Lead Ion Beam”, APAC2007, RRCAT, Indore, India.
[11]
[12]
[13]
[14]
[15]
[16]
[17]
M. E. Angoletta “CERN's PS Complex LLRF renovation: technology, beam results and plans” 1/29

33. 5. References (cont’d) [18]
R. Garoby, M. Haase, P. Maesen, M. Paoluzzi, C. Rossi, C. Ohmori (KEK), “The LEIR RF System”, PAC05, Knoxville, USA, May 2005.
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