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Low Level RF. Outline Scope Local feedback loop requirements Solutions Costs How this fits into global feedback Other signals Conclusions. Scope. The low level RF controls system consists of RF phase and amplitude controls at these locations: Laser Gun L0-A (a.k.a. L0-1) - PowerPoint PPT Presentation
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Dayle Kotturi
Lehman Review [email protected]
May 10-12, 2005
Low Level RF
OutlineScope
Local feedback loop requirements
Solutions
Costs
How this fits into global feedback
Other signals
Conclusions
Dayle Kotturi
Lehman Review [email protected]
May 10-12, 2005
ScopeThe low level RF controls system consists of RF phase and amplitude controls at these locations:
LaserGunL0-A (a.k.a. L0-1)L0-B (a.k.a. L0-2)L0 Transverse cavityL1-SL1-XL2 – using 2 klystrons to control avg phase/ampl of L2L3 Transverse cavityL3 - here is a bit different (lots of klystrons!)
Dayle Kotturi
Lehman Review [email protected]
May 10-12, 2005
Local feedback loop requirements
At each of these locations, the klystron’s phase and amplitude will be controlled
Inputs are listed in Appendix A
Example inputs (for the gun) are:Cell 1 RF monitor. ½” heliax. Phas/ampl 5us 120 Hz
Cell 2 RF monitor ½” heliax. Phas/ampl 5us 120 Hz
RF in FOR. ½” heliax. Phas/ampl 5us 120 Hz
Dayle Kotturi
Lehman Review [email protected]
May 10-12, 2005
Off-the-shelf solution
PAD
Solution 1: Multiple VME crates with COTS modules.
CPU
ADC
fast
ADC
fast
DAC slow
Fast, but no FPGA
Thermocouple system
DAC
fast
EVR
VME Crate
CPU
Global longitudinal beam-based
feedback VME crate
1 trigger for 4 channels of 1k
samples
laser
L0-AL0-B
L1-SL1-XT Cav
gun
Beam-based longitudinal fast feedback gigabit
ethernet
Controls gigabit ethernet (interface to MCC)
RF Reference/4 = 119 MHzstabilized to 50 fs jitter
476 M
Hz R
F Refe
rence
cloc
k dist
ribute
d to a
ll 30 s
ector
s in t
he Li
nac a
nd be
yond
RF Reference*6 = 2856 MHzstabilized to 50 fs jitter
L2: in sector 24, there are 3 stations to adjust in order to accurately control phase and amplitude for long, beam-based fast feedback
10' accelerator
IQ Modulator: a phase shifter
and an attenuator
1 kW 1 kW
100 mW
ADC
slow
RF Reference*6 = 2856 MHzstabilized to 50 fs jitter
Solid State Sub Booster
Klystron
SLED cavity
laser RF
For waveforms e.g. reflected power, beam
voltage
1 trigger to travel up to ½ sector
away
60 MW
HPRF240 MW
60 MW
1 kW
RF Phase and Amplitude correction at 120 Hz for:laser, gun, L0-A, L0-B, L1-S, L1-X, T cav, L2 and S25 Tcav
Slow adjustments to allow rotation
of the reference
phase(inc sensitivity,
dec noise)
All except laser RF
100 mW
119 MHz Laser
Oscillator
Amps
GunNB: For the gun, SLED
cavity is shorted out
119 MHz120 Hz
UV
photodiode
photodiode
Sector 25 T Cav (new 4/2005)
Dayle Kotturi
Lehman Review [email protected]
May 10-12, 2005
Off-the-shelf solution
Test/measure digitizer performance: when clock increases from 105 MHz to 119 MHz, are bits lost?Talking to vendors re: arbitrary function generator (ensure noise < 0.1% ) for pulse shaping with carrier boardDefine interface to PAD Adapt available driver and device support for digitizer to RTEMS
Dayle Kotturi
Lehman Review [email protected]
May 10-12, 2005
In-house solution
I and Q Demo-dulator
CPU
FIFOs
ADC
slow
DAC
slow
Thermocouple system
EVR
VME Crate
CPU
laser
L0-AL0-B
L1-SL1-XT Cav
gun
Beam-based longitudinal
fast feedback gigabit
ethernet
Controls gigabit ethernet (interface to MCC)
Eth recvr
Private ethernet8 kBytes at 120 Hz
PAD
ADC
I and Q Modulator
DAC
FIFOs
1 trigger for 4
channels of 1k
samples
Private ethernet4 kBytes at 120 Hz
Solution 2: Multiple VME crates with in-house modules
476 M
Hz R
F Refe
rence
cloc
k dist
ribute
d to a
ll 30 s
ector
s in t
he Li
nac a
nd be
yond
RF Reference/4 = 119 MHzstabilized to 50 fs jitter
RF Reference*6 = 2856 MHzstabilized to 50 fs jitter
Controller with
ethernet
Controller with
ethernet
Local trigger
Possibly combined into one module
Slow adjustments to allow rotation of the
reference phase
ADC
fast
Other waveformsFast, but not 119
MHz. 59.5 MHz ok
Global longitudinal beam-based
feedback VME crate
L2: in sector 24, there are 3 stations to adjust in order to accurately control phase and amplitude for long, beam-based fast feedback
PAC
Sector 25 T Cav (new 4/2005)
RF Phase and Amplitude correction at 120 Hz for:laser, gun, L0-A, L0-B, L1-S, L1-X, T cav, L2 and S25 Tcav
10' accelerator
IQ Modulator: a phase shifter
and an attenuator
1 kW 1 kW
100 mW
Solid State Sub Booster
Klystron
SLED cavity
60 MW
HPRF240 MW
60 MW
1 kW
All except laser RF
100 mW
119 MHz Laser
Oscillator
Amps
GunNB: For the gun, SLED
cavity is shorted out
119 MHz120 Hz
UV
photodiode
photodiode
1 trigger to travel up to ½ sector
away
Dayle Kotturi
Lehman Review [email protected]
May 10-12, 2005
In-house solution: alternate choice
Requires development of FPGA-based board with ethernet
On-board processing capability for local feedback
Places the digitizers next to the low noise RF components (eliminates transmission of low noise analog signals outside the chassis)
Dayle Kotturi
Lehman Review [email protected]
May 10-12, 2005
L3 solution
CPU
DAC (slow)Updates
@120 Hz;stable 20 µs before
beam arrives and able to distinguish beamcodes
CPU
Global longitudinal beam-based
feedback VME crate
IQ Modulator (driving sub-
booster klystron in sectors 29)
RF Phase and Amplitude correction at 120 Hz for: L3
Beam-based longitudinal fast feedback gigabit
ethernet
Controls gigabit ethernet (interface to MCC)
476
MHz
RF
Refe
renc
e clo
ck d
istrib
uted
to a
ll 30
secto
rs in
the
Linac
and
bey
ond
500 W
IQ Modulator (driving sub-
booster klystron in sectors 30)
klystron
10' accelerator
1 kW 60 MW
HPRF240 MW
60 MW
SLED cavity
500 W
klystron
10' accelerator
1 kW60 MW
HPRF240 MW
60 MW
SLED cavity
Sub Booster Klystron Sub Booster Klystron
100 mW 100 mW
RF Reference*6 = 2856 MHzstabilized to 50 fs jitter
RF Reference/4 = 119 MHzstabilized to 50 fs jitter
1 kW1 kW
8 copies8 copies
Dayle Kotturi
Lehman Review [email protected]
May 10-12, 2005
CostsIn operation, 9 instances of
VME chassis: 6000 €PowerPC: 5000 USDFast digitizer: 5000 USDFast DAC module in carrier board: $unknownAdditional digitizer for waveforms: ~3000KAnalog module for temperatures: ~2000K
And 1 instance (of same) for testing/spares
At L3, 1 instance ofVME chassis: 6000 €PowerPC: 5000 USDAdditional digitizer for waveforms: ~3000KAnalog module for temperatures: ~2000K
Dayle Kotturi
Lehman Review [email protected]
May 10-12, 2005
How this fits into global feedback
TOROID
BUNCH CHARGE
BEAM PHASE CAVITY
GUN RF FEEDBACK
InputsGUN-CELL1-PHAS/AMPLGUN-CELL2-PHAS/AMPL
ActuatorsGUN RF ACTUATORS
2856MHz R ef
GUN RF ACTUATORS
LCLS RF Oscillator
LINAC MDL Ref.
PHAS
GUN RF REF.
LASER RF R EF.
PHAS AMPL
PHASEERROR
ActuatorL0, L1 to L2, L3Phase
AMPL
GUN-CELL2
GUN-CELL1
KLYSTRONAMPLIFIER / SLC CONTROL
LASER OSC
Reference
LASER OSC. PHASE
WATER TEMP
RF GUN
LASER PHASE ACTUATOR
LASER POWERACTUATOR
OUT
GUN TUNE FEEDBACK
InputsGUN-FOR-PHASGUN-CELL1-PHASGUN-CELL2-PHAS
ActuatorsWATER TEMP
GUN-FOR
LASER OSCILLATOR PHASEand LASER POWERFEEDBACK
InputsLASER OSC. PHASEBUNCH CHARGEGUN-CELL1-AMPL/PHASGUN-CELL2-AMPL/PHASLASER PHASE & AMPLITUDEGUN RF ACTUATORSBEAM PHASE CAVITY
ActuatorsLASER POWERLASER PHASE ACTUATOR
PHASE ERROR BetweenL0, L1 and L 2, L3
2856MHzRF REF.
LASER
GUN
L0A
L0B
L0-TCAV1
L1-X
L1-S
LASER PHASE & AMPLITUDE?
LASER AMPLIFIER
Dayle Kotturi
Lehman Review [email protected]
May 10-12, 2005
How this fits into global feedback
L0B LOAD FOR
PHAS
L0B RF REF.
AMPL
L0 BUNCH ENERGYFEEDBACK
Inputs4 DL1BPMs: BPM10,11,12,13Laser phase, power
Matrixed Information DL1 Energy
Status inputs Flags for what is broken
ActuatorsL0 AMPLITUDE
L0A RF PHAS/AMPL0B RF PHAS/AMP
One value lets you control one parameter (L0 amplitude)
DL1 BPM 13X Position
L0B RF ACTUATORS
L0B
L0B THREET HERMOCOUPLEINPUTS
KLYSTRONAMPLIFIER / SLC CONTROL
DL1 BPM 11X Position
DL1 BPM 12X Position
KLYSTRONAMPLIFIER / SLC CONTROL
L0A R F REF.
L0A
L0B RF Feedback
InputsL0B-FOR PHAS/AMPLL0B-LOAD FOR PHAS/AMPL3-THERMOCOUPLES
ActuatorsL0B RF PHAS/AMPL
L0B-FOR
DL1 BPM 10X Position
L0A-FOR
L0A LOAD FOR
L0A T HREETHERMOCOUPLE INPUTS
L0A R F Feedback
InputsL0A-FOR PHAS/AMPLL0A-LOAD FOR PHAS/AMPL3-THERMOCOUPLES
ActuatorsL0A R F PHAS/AMPL
AMPLPHAS
L0A RF ACTUATORS
Dayle Kotturi
Lehman Review [email protected]
May 10-12, 2005
How this fits into global feedback
L1D THREET HERMOCOUPLEINPUTS
L1X-FOR
L1X T HREE THERMOCOUPLEINPUTS
PHAS AMPL
L1 RF ACTUATORS
L1 RF REF.
L1 BUNCH ENERGY/LENGTHFEEDBACK
Inputs4 DL1BPMs: BPM10,11,12,133 BC1BPMs: BPMA12,BPMS11,
BPMM12Toroid atBC1: IMBC1OBLM atBC1: BLM11 Laser phase, power
Matrixed Information DL1 EnergyBC1 Energy and Bunch Length
Status inputs Flags for what is broken
ActuatorsL1 RF PHASL1 RF AMPL
L1C THREET HERMOCOUPLEINPUTSL1B THREET HERMOCOUPLEINPUTS
L1X R F Feedback
InputsL1X-FOR PHAS/AMPLL1X-LOAD FOR PHAS/AMPL3-THERMOCOUPLES
ActuatorsL1X R F PHAS/AMPL
KLYSTRONAMPLIFIER / SLC CONTROL
KLYSTRONAMPLIFIER / SLC CONTROL
L1X RF ACTUATORS
AMPLPHAS
L1X R F REF.
L1B-FOR
L1C LOAD FORL1C
L1XL1X LOAD FOR
L1S R F Feedback
InputsL1B-FOR PHAS/AMPLL1B-LOAD FOR PHAS/AMPLL1C-LOAD FOR PHAS/AMPLL1D-LOAD FOR PHAS/AMPLL1B 3 THERMOCOUPLESL1C 3 THERMOCOUPLESL1D 3 THERMOCOUPLES
ActuatorsL1 RF PHAS/AMPL
L1D LOAD FOR
BC1 BPMM12X Position
BC1 BPMS11X Position
BC1 BPMA12X Position
L1D
BC1BUNCHLENGTHL1B LOAD FOR
L1B
Dayle Kotturi
Lehman Review [email protected]
May 10-12, 2005
How this fits into global feedback
L2 24-1
L2 24-1 RF ACTUATORS
PRL RF
PHAS AMPL
KLYSTRONAMPLIFIER / SLC CONTROL
L2 24-2 RF ACTUATORS
L2 24-2
KLYSTRONAMPLIFIER / SLC CONTROL
AMPLPHAS
PRL RF
L2 BUNCH ENERGY/LENGTHFEEDBACK
Inputs4 DL1BPMs: BPM10,11,12,133 BC1BPMs: BPMA12,BPMS11,
BPMM123 BC2BPMs: BPM24401,
BPM24701,BPMS21Toroid atBC1: IMBC1OToroid atBC2: IMBC2OBLM atBC1: BLM11 BLM atBC2: BLM21Laser phase, power
Matrixed Information DL1 EnergyBC1 Energy and Bunch Length BC2 Energy and Bunch Length
Status inputs Flags for what is broken
ActuatorsL2 PHASE AND AMPLITUDE
L2 24-1 R FPHAS ACTUATORL2 24-2 R FPHAS ACTUATOR
BC2 BPM24401X Position
BC2 BPM24701X Position
BC2 BPMS21X Position
BC2 BUNCHLENGTH
Dayle Kotturi
Lehman Review [email protected]
May 10-12, 2005
How this fits into global feedback
DL2 BPMDL3X Position
PRL RF
8 KLYSTRONAMPLIFIER / SLC CONTROL
SECTOR 28SECTOR 27 DL2 BPMDL1X Position
8 KLYSTRONAMPLIFIER / SLC CONTROL
SECTOR 27 PHASE ACTUATOR
PRL RF
L3 BUNCH ENERGYFEEDBACK
Inputs4 DL1BPMs: BPM10,11,12,133 BC1BPMs: BPMA12,BPMS11,
BPMM123 BC2BPMs: BPM24401,
BPM24701,BPMS212 DL2BPMs: BPMDL1,BPMDL3Toroid atBC1: IMBC1OToroid atBC2: IMBC2OBLM atBC1: BLM11 BLM atBC2: BLM21Laser phase, power
Matrixed Information DL1 EnergyBC1 Energy and Bunch Length BC2 Energy and Bunch LengthDL2 Energy
Status inputs Flags for what is broken
ActuatorsL3 AMPLITUDE
SECTOR 29PHAS ACTUATORSECTOR 30PHAS ACTUATOR
SECTOR 28PHASE ACTUATOR
Dayle Kotturi
Lehman Review [email protected]
May 10-12, 2005
How this fits into global feedback
L3 RF phase*L3 RF amplitude*
L2 RF phase*L2 RF amplitude*
BC-2 energyBC-2 bunch length
LIST OF AVAILABLE PARAMETERSupdated at 120 Hz unless specified otherwise
Laser phaseLaser powerGun RF phaseGun RF amplitudeGun chargeBeam phaseL0A RF phaseL0A RF amplitudeL0B RF phaseL0B RF amplitudeDL1 energyL1 RF phaseL1 RF amplitudeL1-X RF phaseL1-X RF amplitudeBC-1 energyBC-1 bunch length
DL2 energy
*Discussion needed here: - these 10 sectors*8 klystron values are available from the SCP, but maybe impossible to read them@ 120 Hz. Alternatively, we could provide the corrected values @120 Hz.
Dayle Kotturi
Lehman Review [email protected]
May 10-12, 2005
Other signals – (listed in Appendix A)
Control signalsThis is the feedback’s calculated new phase/amplitude
Need pulse shaping
Pulse shaping would be entered manually
Don’t know where yet
Very low processing load
Dayle Kotturi
Lehman Review [email protected]
May 10-12, 2005
Conclusions
By using multiple VME chassis (10 over injector, sectors 24 & 30), the LCLS LLRF raw signals can be processed by the CPU in time to send out phase and amplitude corrections and have them settle within a beam pulse.
When there is beam, this system will integrate with the beam-based longitudinal feedback by accepting the latter’s RF phase and amplitude corrections and passing them on.
Dayle Kotturi
Lehman Review [email protected]
May 10-12, 2005
Appendix ARF Cables - Monitor and Control Signals – from LCLS ESD 1.2-137 (Akre, Hill)Legend: Monitor. Feedback. Control.
From RF HUT
Sub-system Signal Name Cable Type To Location Signal Type
Laser RF Reference 1/2" Heliax Laser Room Phas/Ampl CW
Laser Oscillator Out 1/2" Heliax Laser Room Phas/Ampl CW
120Hz Laser Pulse 1/2" Heliax Laser Room Phas/Ampl picoSec
RF Control RF Hut Phas/Ampl CW
Gun Cell 1 RF Monitor 1/2" Heliax Gun Phas/Ampl 5uS 120Hz
Cell 2 RF Monitor 1/2" Heliax Gun Phas/Ampl 5uS 120Hz
RF In FOR 1/2" Heliax Gun Phas/Ampl 5uS 120Hz
RF In REFL 1/2" Heliax Gun Phas/Ampl 5uS 120Hz
RF Control 1/2" Heliax 20-6 120Hz
Dayle Kotturi
Lehman Review [email protected]
May 10-12, 2005
Appendix A continuedL0-A RF In FOR 1/2" Heliax L0-1 Phas/Ampl 5uS 120Hz
RF In REFL 1/2" Heliax L0-1 Phas/Ampl 5uS 120Hz Load FOR 1/2" Heliax L0-1 Phas/Ampl 5uS 120Hz Load REFL 1/2" Heliax L0-1 Phas/Ampl 5uS 120Hz
RF Control 1/2" Heliax 20-7 120Hz
L0-B RF In FOR 1/2" Heliax L0-2 Phas/Ampl 5uS 120Hz RF In REFL 1/2" Heliax L0-2 Phas/Ampl 5uS 120Hz Load FOR 1/2" Heliax L0-2 Phas/Ampl 5uS 120Hz Load REFL 1/2" Heliax L0-2 Phas/Ampl 5uS 120Hz RF Control 1/2" Heliax 20-8 120Hz
Dayle Kotturi
Lehman Review [email protected]
May 10-12, 2005
Appendix A continuedL0- Transverse
RF In FOR 1/2" Heliax L0- Transverse Phas/Ampl 5uS 120Hz
RF In REFL 1/2" Heliax L0- Transverse Phas/Ampl 5uS 120Hz
Load FOR 1/2" Heliax L0- Transverse Phas/Ampl 5uS 120Hz
Load REFL 1/2" Heliax L0- Transverse Phas/Ampl 5uS 120Hz
RF Control 1/2" Heliax 20-5 120Hz
L1-S SLED Out FOR 1/2" Heliax 21-1
SLED Out REFL 1/2" Heliax 21-1
ACC A/B In FOR 1/2" Heliax 21-1 Phas/Ampl 5uS 120Hz
ACC A/B In REFL 1/2" Heliax 21-1 Phas/Ampl 5uS 120Hz
ACC C IN FOR 1/2" Heliax 21-1 Phas/Ampl 5uS 120Hz
ACC C IN REFL 1/2" Heliax 21-1 Phas/Ampl 5uS 120Hz
Load A/B FOR 1/2" Heliax 21-1 Phas/Ampl 5uS 120Hz
Load A/B REFL 1/2" Heliax 21-1 Phas/Ampl 5uS 120Hz
Load C FOR 1/2" Heliax 21-1 Phas/Ampl 5uS 120Hz
Load C REFL 1/2" Heliax 21-1 Phas/Ampl 5uS 120Hz
RF Control 1/2" Heliax 21-1 120Hz
Dayle Kotturi
Lehman Review [email protected]
May 10-12, 2005
Appendix A continuedL1-X
KLY Out RF FOR 3/8" Heliax 21-2 Phas/Ampl 2uS 120Hz
KLY Out RF REFL 3/8" Heliax 21-2 Phas/Ampl 2uS 120Hz
ACC In FOR 3/8" Heliax 21-2 Phas/Ampl 2uS 120Hz
ACC In REFL 3/8" Heliax 21-2 Phas/Ampl 2uS 120Hz
Load FOR 3/8" Heliax 21-2 Phas/Ampl 2uS 120Hz
Load REFL 3/8" Heliax 21-2 Phas/Ampl 2uS 120Hz
FB Control 3/8" Heliax 21-2 120Hz
L3-Transverse
RF In FOR 1/2" Heliax 25-5A Phas/Ampl 5uS 120Hz
RF In REFL 1/2" Heliax 25-5A Phas/Ampl 5uS 120Hz
Load FOR 1/2" Heliax 25-5A Phas/Ampl 5uS 120Hz
Load REFL 1/2" Heliax 25-5A Phas/Ampl 5uS 120Hz
RF Control 1/2" Heliax 24-8 120Hz