Low Level RF Control System!
Brian Chase for the LLRF team!PIP-II Machine Advisory Committee Meeting!15-17 March 2016!!!
Outline!
• System overview!– LLRF!– Reference line!– ! 4 cavity Station!– Controller cards!– Piezo amp for resonance control!
• RFQ commissioning results!• Requirements and design approach!
– 0.01°, 0.01% rms beam stability!– 0.1°, 0.1% rms field stability per cavity!– Large non deterministic detuning errors !
• Collaborations!– India !– Colorado State University!
• Current system development!– Master Oscillator and Reference line!– Controller module!
• System on module!
3/16/2016!Brian Chase | P2MAC_2016!2!
TeamADLLRF-E.Cullerton,P.Varghese,J.Edelen,J.Einstein,D.KlepecIIFC-G.Joshi,S.Khole,D.Sharma,&manyothersCSU–A.Edelen
PXIE Low Level RF Group Involvement!
3/16/2016!Brian Chase | P2MAC_2016!3!
PXIE will address the address/measure the following:!– LEBT pre-chopping !– Vacuum management in the LEBT/RFQ region!– Validation of chopper performance!– Bunch extinction!– MEBT beam absorber!– MEBT vacuum management!– Operation of HWR in close proximity to 10 kW absorber!– Operation of SSR with beam, including resonance control and LFD compensation
in pulsed operations!– Emittance preservation and beam halo formation through the front end!
40 m, ~25 MeV
30keVRFQ MEBT HWR SSR1 HEBT LEBT
2.1MeV 10MeV 25MeV201720162015Now 2018
LLRF Systems needed to meet R&D Goals!
• 325 MHz Horizontal test stand !– Support for CW and pulsed mode operation!– Operational !
• 650 MHz Horizontal test stand !– Support for CW and pulsed mode operation!– Supplied by India Q3FY16!
• PXIE !– Master Oscillator and Phase Reference distribution line!
• 162.5 MHz & 325 MHz (Operational with synthesizer)!– RFQ – 162.5 MHz (Q4FY15)!
• 2 RF amplifier system (In system test/ resonance testing)!– Buncher - 3 cavities - 162.5 MHz (FY15) (Ready for 1st buncher)!– Half Wave Resonators - 8 cavities @162.5 MHz (FY17)!– SSR1 - 8 cavities @ 325 MHz (FY17)!– Kicker waveform generator!
3/16/2016!Brian Chase | P2MAC_2016!4!
PIXIE RF Stations Diagram!
5!
January 14, 2013
Page 1
PXIE LLRF DIAGRAM
M M M M M M M M M M M M M M M M
Half-wave Resonator Cryomodule(HWR)(162.5MHz.)
Single-spoke Resonator Cryomodule(SSR1)(325MHz.)
RFQ
BUNCHING CAVITY1
#1
FAST CHOPPER
#2
FAST CHOPPER
BUNCHING CAVITY2
BUNCHING CAVITY3
ABSORBER
MEBT(162.5MHz.)LEBT
HWR
BPM & Corrector
coilHWR
HWR
HWR
HWR
HWR
HWR
HWR
Corrector
coil & BPM
SSR1
DUMP
(162.5MHz.)
LLRF crate 1:- CPU, PS- 2 LLRF MFC- Timing Distribution
SSRCavREV [1..8]SSRCavFWD [1..8]
SSRCavProbe [1..8]
1……………………...8
3XLLRF crate 1:- CPU, PS- 3 LLRF MFC- Timing Distribution HWRCavREV[1..8]
HWRCavFWD[1..8]HWRCavProbe [1..8]
3X
1……………………...8
PAPA
CHOPPERPROGRAM MODULE
BCavProbe3
BCavProbe2BCavProbe1
RFQProbe
RFQREV
RFQFWD
BCavREV1
BCavFWD1
BCavREV2
BCavFWD2 BCavFWD3
BCavREV3
2X
RFQProbe, BCavREV[1..3]RFQFWD, BCavFWD[1..3]RFQREV, BCavProbe[1..3]
Reference Tap
HWRCavREV1
HWRCavFWD1 HWRCavFWD8
HWRCavREV8 SSRCavREV1
SSRCavFWD1 SSRCavFWD8
SSRCavREV8
HWRCavProbe1
HWRCavProbe8
SSRCavProbe1 SSRCavProbe8
Reference Tap
PA PA PA PA PA PA
LLRF crate 2:- CPU, PS- Interlock Systems
LLRF crate 2:- CPU, PS- Interlock Systems
LLRF crate 3:- CPU, PS- Motor Controller- Resonance Controller
LLRF crate 2:- CPU, PS- Motor Controller- Resonance Controller
Local OscillatorTiming & Synchronization
Inter-System Feedback Network/BusMPS Network/Bus
RT Control Network
LLRF crate 2:- CPU, PS- Motor Controller- Resonance Controller
162.5Interlock[1..12] 325Interlocks[1..8]
162.5Interlock1 162.5Interlock5 162.5Interlock12 325Interlock1 325Interlock8162.5Interlock2 162.5Interlock3 162.5Interlock4
162.5ResonanceCntrl[1..12] 325ResonanceCntrl[1..8]
24
36
16
24
162.5ResonanceCntrl5
162.5ResonanceCntrl12 325ResonanceCntrl1 325ResonanceCnrtl8162.5ResonanceCntrl1
162.5ResonanceCntrl4
162.5ResonanceCntrl3162.5ResonanceCntrl3
FAST CHOPPER
B. Chase, E. Cullerton, D. Klepec1/14/13
Version 1.0
Brian Chase | P2MAC_2016! 3/16/2016!
Phase Reference Lines (162.5, 325, 650 ,1300 MHz)!
3/16/2016!Brian Chase | P2MAC_2016!6!
MulI-frequencyPhaseReferencesandLocalOscillatorsWearebuildingupthefirstsecIonsforPXIE
Details of First 162.5 MHz RF Section!
3/16/2016!Brian Chase | P2MAC_2016!7!
Phasestabilityacrossharmonics(400fs)TemperaturecontrolledracksandcomponentplatesWehavethisexperienceandseeapathforward
PIP-II LLRF 4 Cavity LLRF Rack Layout!
DownconvertersforPXIEaredoneController,PZTamp,steppermotorcontroller,Upconverterindesignstage
3/16/2016!Brian Chase | P2MAC_2016!8!
Basic LLRF Station Diagram for 4 cavities!
2/17/2016Presenter | Presentation Title1
RF Boards
UC
DCN
N
N
N
DCN
N
N
N
SMA
SMA
N
N
N
RFPI
FPGASMA SMA
GbE
Cavity2
Amp CirRFS/W
DC
RFPI
FPGASMA SMA
GbE
Cavity1
Amp CirRFS/W
DC
Timing / Events
MPS
Controls
LLRF Controller
SOCFPGABoard
CLK
ADC
FMC
SFPSFP
SFP DAC
GbE
SMA
SFP
SMA
SMA
SMA
LLRF Controller
SOCFPGABoard
CLK
ADC
FMC
SFPSFP
SFP DAC
GbE
SMA
SFP
SMA
SMA
SMA
Cavity4
Amp CirRFS/W
DC
Cavity3
Amp CirRFS/W
DC
Clock Distribution
N
N
Resonance Controller
StepperControl
PiezoControl
SOCFPGABoard
FMC
SFPSFP
SFP
GbE
SMA
SFP
Audio
Audio
345 MHzTiming/Triggers(Optical)
MPS Triggers (Optical)
Signal Name (Optical)
1320 MHz
Ref Clk
Ref Clk
6
2
2
2
2
8
8
2
2
6
Signal Name (Optical)
2
3
3
3
3
3
Controls Signal for LLRF (GbE)
Controls Signal for RFPI (GbE)
Controls Signal for RFPI (GbE)
325 MHz
325 MHz
325 MHz
325 MHz
325 MHz
325 MHz
20 MHz
20 MHz
Signal Name
Signal Name? MHz
? MHz
3/16/2016!Brian Chase | P2MAC_2016!9!
PXIE LLRF rack layout - front and rear view!
3/16/2016!Brian Chase | P2MAC_2016!10!
RFQ HWR SSR
System on Chip Multi-channel Field Controller!
3/16/2016!Brian Chase | P2MAC_2016!11!
(16)14bitADCs (8)14bitDACs SystemonModule
DualcoreArmprocessorwithFPGAmayeliminatetheneedforabackplaneandCPUcard
12! Brian Chase | P2MAC_2016!
• Minimize microphonics to <10 Hz !• 1 Hz or better resolution !• +- 1kHz tuning range !• 2 drive amplifiers for 2 piezo stack groups per cavity (1 module per cavity)!4 drive modules per chassis!
3/16/2016!
Piezo Resonance Control Requirements!
13! Brian Chase | P2MAC_2016!
Piezo Amplifier – PDu150!
Each amp drives 2.2uF piezo loads
Resonance Control Loop!
Brian Chase | P2MAC_2016!14!
Cavity Tuner
System
Stepper Control
Piezo Control Loop
n
Disturbances
Feed Forward
Error
Flags High-Level Piezo
Control
Range Check
LLRF Controller
(RF Vectors)
+ -
+
Setpoint (Hz)
Controller
FF
++
+ Hz-to-V
(Flags)
(Hz)
(ENABLE) (Hz) (Volts)
Cavity Resonance Frequency Error (Hz)
Piezo Amplifier single tone and noise performance!
Brian Chase | P2MAC_2016!15!
LowdistorIonwith86Hzsinewave-109dBV/√Hz@292Hz
IIFC LLRF Status!
5
5
4
4
3
3
2
2
1
1
D D
C C
B B
A A
ADC_FCO_NADC_FCO_P
ADC_DCO_NADC_DCO_P
ADC_A_D0_NADC_A_D0_P
ADC_A_D1_NADC_A_D1_P
ADC_MOSIADC_SCK
ADC_CS
ADC_B_D0_NADC_B_D0_P
ADC_B_D1_NADC_B_D1_P
ADC_C_D0_NADC_C_D0_P
ADC_C_D1_NADC_C_D1_P
ADC_D_D0_NADC_D_D0_P
ADC_D_D1_NADC_D_D1_P
ADC_CLK_PADC_CLK_N
ADC_FCO_NADC_FCO_P
ADC_DCO_NADC_DCO_P
ADC_A_D0_NADC_A_D0_P
ADC_A_D1_NADC_A_D1_P
ADC_B_D0_NADC_B_D0_P
ADC_B_D1_NADC_B_D1_P
ADC_C_D0_NADC_C_D0_P
ADC_C_D1_NADC_C_D1_P
ADC_D_D0_NADC_D_D0_P
ADC_D_D1_NADC_D_D1_P
GND
GND
VCM
VIN_A_P
VIN_A_N
VIN_B_N
GND
GND VIN_B_P
VIN_C_N
VIN_D_N
GND
GND VIN_D_P
GND
GND VIN_C_P
VIN_A_NVIN_A_P
VIN_B_NVIN_B_P
VIN_C_NVIN_C_P
VIN_D_NVIN_D_P
VCMGND
GND VCM
GND VCM
GND VCM
AVDD_1.8V
AV
DD
_1.8
VA
VD
D_1.8
V
AV
DD
_1.8
VA
VD
D_1.8
V
DV
DD
_1.8
V
GN
D
AV
DD
_1.8
VA
VD
D_1.8
VA
VD
D_1.8
V
DV
DD
_1.8
V
GND
ADC_VREF
GND
ADC_CLK_P
ADC_CLK_N
ADC_SYNCADC_PDWN
GND
DVDD_1.8V
AVDD_1.8V
GND
ADC_VREF
ADC_SYNC
ADC_PDWN
ADC_MOSI
ADC_SCK
ADC_CS
ADC_DCO_PADC_DCO_N
ADC_A_D1_PADC_A_D1_N
ADC_A_D0_PADC_A_D0_N
ADC_B_D1_PADC_B_D1_N
ADC_B_D0_PADC_B_D0_N
ADC_C_D1_PADC_C_D1_N
ADC_C_D0_PADC_C_D0_N
ADC_D_D1_PADC_D_D1_N
ADC_D_D0_PADC_D_D0_N
ADC_FCO_PADC_FCO_N
ADC_CLK_P
ADC_CLK_N
DAC_GND
ADC_DVDD_1.8V
ADC_AVDD_1.8V
ADC_VREF
ADC_SCK
ADC_MOSI
ADC_CS
ADC_SYNC
ADC_PDWNTitle
Size Document Number Rev
Date: Sheet of
<Doc> <RevCode>
<Title>
B
1 1Friday, February 19, 2016
Title
Size Document Number Rev
Date: Sheet of
<Doc> <RevCode>
<Title>
B
1 1Friday, February 19, 2016
Title
Size Document Number Rev
Date: Sheet of
<Doc> <RevCode>
<Title>
B
1 1Friday, February 19, 2016
R?
10k
R?
10k
R?
49.9
R?
49.9
C14 100nC14 100n
R?
200
R?
200
C19
10n
C19
10n
C21
10n
C21
10nT5
ADT2-1T-1P
T5
ADT2-1T-1P
P13 S1 4
SC 5
P21 S2 6
NC2
L4
100n
L4
100n
1
2
C13634PC13634P
C18
10n
C18
10n
C6 100nC6 100n
L1
100n
L1
100n
1
2
C15 100nC15 100n
R?
49.9
R?
49.9
R?
200
R?
200
J3J31
2345
C12 100nC12 100n R?
200
R?
200
R?
49.9
R?
49.9
R?
49.9
R?
49.9
C20
10n
C20
10n
C22
10n
C22
10n
J1J11
2345
R?
100
R?
100
T1
ADT2-1T-1P
T1
ADT2-1T-1P
P13 S1 4
SC 5
P21 S2 6
NC2
C5 100nC5 100n
C7634PC7634P
C11 100nC11 100nT4
ADT2-1T-1P
T4
ADT2-1T-1P
P13 S1 4
SC 5
P21 S2 6
NC2
C8 100nC8 100n
J4J41
2345
C17
10n
C17
10n
C24 100nC24 100n
R?
49.9
R?
49.9
T3
ADT2-1T-1P
T3
ADT2-1T-1P
P13 S1 4
SC 5
P21 S2 6
NC2
L2
100n
L2
100n
1
2
J5J51
2345
U1
AD9653BCPZ-125
U1
AD9653BCPZ-125
VIN+D1
VIN-D2
AV
DD
3
AV
DD
_1
4
CLK-5CLK+6
AV
DD
_2
7
DR
VD
D8
D1-D 9D1+D 10
D0-D 11D0+D 12
D1-C 13D1+C 14
D0-C 15D0+C 16
DCO- 17
DCO+ 18
FCO- 19FCO+ 20
D1-B 21
D1+B 22
D0-B 23D0+B 24
D1-A 25D1+A 26
D0-A 27D0+A 28
DR
VD
D_1
29
SCLK/DTP 30
SDIO/OLM 31
CSB 32
PDWN 33
AV
DD
_3
34
VIN-A35VIN+A36
VIN+B37
VIN-B38
AV
DD
_4
39
RBIAS40
SENSE41
VREF42
VCM43
SYNC 44
AV
DD
_5
45
AV
DD
_6
46
VIN-C47VIN+C48
EP
49
C23 100nC23 100n
C16634PC16634P
R?
10k
R?
10k
C9 100nC9 100n
R?
49.9
R?
49.9
L3
100n
L3
100n
1
2
C10634PC10634P
R?
1K 0.1%
R?
1K 0.1%
R?
49.9
R?
49.9
R?
49.9
R?
49.9
R?
200
R?
200
3/16/2016!Brian Chase | P2MAC_2016!16!
CardswithschemaIcs- ADC/DAC,FPGA,Up-converter- Down-converter,PiezoamplifierLayoutsarecomingsoonTwoengineersareworkingherewithusforatwoyearperiod
RFQ disturbance response!
3/16/2016!Brian Chase | P2MAC_2016!17!
ClosedloopQl=6900Kp=6Ki=3.5e6sehlingIme~10µsecInloopnoisemeasurement0.008%rms,<0.002°rms
Openloopresponsetoa20µsecfullscaledisturbance
Feedback gain studies!
• Percentage error in the cavity field amplitude at 20 microseconds after a disturbance!
• The disturbance was 10% of full scale !
• For cases with large integral gain and low proportional gain, the feedback loop is unstable !
3/16/2016!Brian Chase | P2MAC_2016!18!
RFQ resonance controlvane system step response!
• Transient response of the RFQ resonant frequency due to change in the vane flow control valve. Prior to changing the flow valve, the intermediate skid was cooled to approximately 25C. The control valve was stepped from 0% open to 50% open.
!
initial transient steady stateTime 0 7.2 min 115.4 min�f
res
0 46.13 kHz 21.15 kHzTT101 22.280 oC 25.796 oC 25.649 oCTT102 31.489 oC 28.126 oC 26.141 oCTT103 30.941 oC 27.639 oC 26.284 oC
flow path time delay [s]
TT101 ! TT103 1.0
TT103 ! TT102 17.0
3/16/2016!Brian Chase | P2MAC_2016!19!
RFQ Water system overview!
M4#
M3#
M2#
M1#
M4#
M3#
M2#
M1#
π
Wall Vane
filter# filter#
pump# pump#
thermal connection through Cu cold supply warm return π
π
π
FCV#FCV#
delay#
Helical#mixer#
Helical#mixer#
delay#
delay#
delay#
delay#
damping#damping#
varied#delay#
varied#delay#
cave wall delay#
Intermediate#Skid#Brian Chase | P2MAC_2016!20!
Feedback modeling!
• Expecting large disturbances from LFD, want fast response from beam loading transient !
– get 15 dB from feedforward beamloading compensation!
• Approach - find highest stable loop gain and determine system noise requirements !
• Determine best gain settings from operational experience and needs of beam-based feedback!
– It is easy to turn down the gain on a well designed system, impossible to turn up gain on a poorly designed one!
• Assume a low noise oscillator!– Wenzel VHF ULN 100 MHz 13.7 dBm!– % http://www.wenzel.com/model/vhf-uln/!
• System loop delay of 2.1 µsec!• Cavity bandwidth 30 Hz
3/16/2016!Brian Chase | P2MAC_2016!21!
o Baseband cavity model is a low pass filter with a bandwidth determined by Ql and !0:
Tcav(s) =
!0/Qls+!0/Ql
o In the simplest case the feed-forward component of the system is simply the set-point
o Initially assume that the I and Q loops are driven with the same PI parameters
Vbeam
Vset Kp +
1sKi Tcav(s) Vcav
�e�st0
Figure: Baseband model of LLRF control system. Middle row (from left to right): Set-point,
summing junction for feedback, PI controller, summing junction for feed-forward, summing
junction for beam-loading, cavity transfer function, and cavity probe signal. Bottom row:
group delay (negative for negative feedback). Top row: beam-loading
Simulation of open loop transfer function of cavity and controller!
3/16/2016!Brian Chase | P2MAC_2016!22!
Magnitude Phase
Closed-loopbandwidth:~50kHzControlsystemzero:15kHzProporIonalgain:1500Integralgain:1.44e+08
CodedevelopedforLCLS-IILarryDoolihleLBNLandFNAL
Total phase noise to SSA from controller and oscillator sources!
• Cavity: 0.00078° rms!• SSA: 1.04°!• SSA from ADC: 0.96°!
3/16/2016!Brian Chase | P2MAC_2016!23!
Closedloopresponse CumulaIveSSAphasenoisevoltage
CarefulahenIontonoisetermswillallowhighcontrollergains
Conclusions!
• The LLRF Group is commissioning and developing systems for PXIE!– Development of a next generation system controller card!– Development of the multi-frequency reference !– RFQ resonance control!– MEBT/kicker waveform generator!– Simulation tools!
• Collaboration with India to deliver next generation systems for test stands and LLRF control for the 120 cavities of PIP-II!
3/16/2016!Brian Chase | P2MAC_2016!24!
Thank you for your attention!!
3/16/2016!Brian Chase | P2MAC_2016!25!
Primary Technical Risks !
• Resonance Control for 5 new cavity designs!– Lorentz Force Detuning compensation for narrow bandwidth cavities operated
in pulsed mode!– New cavity designs with new mechanical properties!– ~20 Hz half BW with expected 420 Hz Lorentz Force Detuning in SSR1!
• Development of the LEBT/MEBT Chopper Program Module!– Wideband beam-based learning algorithm!
• 10-3 regulation of amplitude and phase in pulsed mode with high Q cavities!
• 10-4 regulation with beam based feedback!
!
!
Brian Chase | P2MAC_2016!
26!!
3/16/2016!
Parameters of RF Cavities!
Brian Chase | P2MAC_2016!27!
#Frequency(MHz) Section
Amplitude(MV)
SynchronousPhase(deg) Pg(kW)
1 162.5 MEBT 0.088 -90 2.672 162.5 MEBT 0.065 -90 1.453 162.5 MEBT 0.079 -90 2.134 162.5 HWR 0.44 -48.06 0.3255 162.5 HWR 0.7 -35 0.7896 162.5 HWR 0.85 -33.95 1.1557 162.5 HWR 1 -26 1.6188 162.5 HWR 1.5 -24.03 3.3129 162.5 HWR 1.5 -20.02 3.35110 162.5 HWR 1.6 -22 3.72411 162.5 HWR 1.7 -23.98 4.10512 325 SSR1 1 -32.96 0.90413 325 SSR1 1 -29.99 0.94614 325 SSR1 1.1 -28.01 1.12715 325 SSR1 1.25 -27.03 1.39916 325 SSR1 1.5 -26.03 1.8917 325 SSR1 1.5 -27.01 1.91518 325 SSR1 1.5 -25 1.95619 325 SSR1 2.2 -23.98 3.62220 243.75 HEBT 1.07* n/a 2.9 *Amplitudeoftransversekick
3/16/2016!
Major Milestones !
Brian Chase | P2MAC_2016!28! 3/16/2016!
RF Power budget and Ql!
3/16/2016!Brian Chase | P2MAC_2016!29!
TotalcavitydetuningbudgetincludingLFD
MeasuredLFDis22ImeslargerthantheenIreresonanceerrorbudget
DiscussionsareinprogressaboutopImizingamplifiersandQLforpulsedoperaIon
Ongoingcavitydesigneffortstolowerthesenumbers
Mayneedreal-Imefeedbackduringpulse