Download - R&D ERL ERL LLRF System
February 17-18, 2010
R&D ERL
Kevin S. Smith
R&D ERLERL LLRF System
Kevin S. Smith
February 17-18, 2010
LLRF System
February 17-18, 2010
R&D ERL
Kevin S. Smith
LLRF Control Requirements
• Three major sub-system components– 50 kW 5-Cell ERL SRF Cavity, Qext = 3E7
– 1 MW SRF Photocathode Gun, Qext = 40E3
– Laser
• Cavity Field Control Objectives– Amplitude : 0.01% pp
– Phase : 0.05 deg rms
• Laser Control Objective– 9.383 MHz (h=120) phase reference with < 400fs rms integrated jitter
• Energy regulation feasibility
• User Interface and Diagnostic Data
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February 17-18, 2010
R&D ERL
Kevin S. Smith
• Carrier Board− Stand alone control system interface, daughter host platform,
communication hub, timing, data acquisition management, power …
• Daughter Module– Provide system specific functionality (ADCs, DACs, DSP, etc.) and signal
processing horsepower
• A LLRF Controller is a stand-alone configurable, modular, hardware / software platform, the basic building block from which a complete LLRF system is built up.
• Two major components from which any Controller is configured:– “Controller” = “Carrier Board” + “Daughter Modules”
BNL Generic LLRF Controller
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• R&D ERL system is a variant of the recently developed generic LLRF Controller, currently being commissioned at both RHIC and the EBIS injector for RHIC
February 17-18, 2010
R&D ERL
Kevin S. Smith
LLRF Controller Major Features
• Carrier Board– Xilinx Virtex-5 FX FPGA with remote reconfiguration via ethernet– Embedded RHIC Front End Computer (FEC) with all Controls links– 1x 10/100/1000 Ethernet, 1x 10/100 Ethernet, 2x RS-232– 3x 3.25 Gb/s multi-protocol external (chassis to chassis) serial links– 1 Gbyte DDR2 SO-DIMM, 32 Mbyte Configuration FLASH– Multiple clock distribution, RF “Update Link” distribution– External RF IOs and monitors, digital IOs– Monitoring of Carrier and Daughter system health (temps, voltages, currents)
• Daughter Modules– Xilinx Virtex-5 FX, SX or LX FPGA with remote reconfiguration via ethernet– 6x 3.25 Gb/s serial links (per site) to carrier (2) and nearest neighbors (4)– 1 Gbyte DDR2 SO-DIMM, 32 Mbyte Configuration FLASH, 2x RS-232– Flexible low noise PLL and clock distribution– Standard interface to carrier via “XMC” mezzanine format, COTs compatible– Custom “front ends”: ADCs, DACs, DSPs, etc.
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February 17-18, 2010
R&D ERL
Kevin S. Smith
LLRF System Block Diagram
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WAVEGUIDE TUNER
WAVEGUIDE TUNER
LOAD
IOT
IF
LO
RF
IF
LO
RF
IF
LO
RF
ERL 5-CELL703.75 MHz
20 MeV
BEAM DUMP
BPM
IF
LO
RF
FIELD PROBE
RF GUN BEAM PHASE
PICKUP
OUTSIDE
INSIDE
ERL TEST FACILITY, BLDG 912LLRF CONTROL BLOCK DIAGRAMREV A02/04/2010KSS
PIEZO TUNER
PIEZO TUNER
“LASER BEAM”
RF GUN703.75 MHz
2.5 MeV
IF
LO
RF
IF
LO
RF
IF
LO
RF
IF
LO
RF
CIRCULATING BEAM PHASE
PICKUP
LOAD
IOT
IF
LO
RF
IF
LO
RF
IF
LO
RF
IF
LO
RF
LLRF Controller 15-Cell Cavity and Beam Feedback
LLRF Controller 2RF Photocathoide Gun and Laser
1600 MHz PLL
100 MHzUltra Low NoiseMaster Oscillator
RHICEVENT
LINK
800 MHz 800 MHz SAT
RF
DR
IVE
P F
OW
AR
D
P R
EF
LEC
TE
D
FIE
LD
PR
OB
E
RF
DR
IVE
P F
OW
AR
D
P R
EF
LEC
TE
D
FIE
LD
PR
OB
E
TU
NIN
G R
EF
TU
NIN
G R
EF
BP
M O
UT
SID
E
BP
M IN
SID
E
PH
AS
E C
IRC
UL
AT
ING
BE
AM
PH
AS
E I
NJE
CT
ED
BE
AM
PULSE PICKER TRIGGER
LASER RF REFERENCE
LA
SE
R R
F R
EF
PU
LS
E P
ICK
ER
R
EF
2.5 Gbit SERAL LINK
2.5 Gbit SERAL LINK
2.5
Gb
it S
ER
AL
LIN
K
2.5
Gb
it S
ER
AL
LIN
K
RHICRTDL
LLRF UPDATE
LINKGigE
RHICEVENT
LINK
RHICRTDL
LLRF UPDATE
LINKGigE
EXTERNAL 100 MHz
REF
February 17-18, 2010
R&D ERL
Kevin S. Smith
LLRF System Topology
• System is a variant of the BNL RHIC and EBIS LLRF systems currently undergoing development and commissioning
• Generator Driven Resonator− Very commonly used (CEBAF, SNS, Cornell …)
− Amplitude and Phase stabilization via digital IQ control loop readily implemented in modern FPGA based systems
− Intrigued by JLAB digital SEL as well
− Currently characterizing 5-cell cavity behavior using analog PLL system.
• RF DACs are 16 bit, 400 MSPS, 1 GHz analog BW
• RF ADCs are 16 bit, 100 MSPS, 700 MHz analog BW
• Current plan is to use a 96.25 MHz IF = 800 MHz – 703.75 MHz
• Systems based on similar technology have already demonstrated 0.01% amplitude and 0.02 deg phase stability
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