Ron Akre, Dayle Kotturi LCLS [email protected]@slac.stanford.edu, [email protected]@slac.stanford.edu April 20, 2006 Linac Coherent

Ron Akre, Dayle Kotturi

LCLS LLRF [email protected], [email protected]

April 20, 2006

Linac Coherent Light Source (LCLS)

Low Level RF System

Injector Turn-on December 2006

April 20, 2006



April 20, 2006

Safety First and Second and Third…..to Infinity

Hazards in the LLRF systemRF 1kW at 120Hz at 5uS = 0.6 Watts average, 2 Watt average amps at 2856MHz, 60W average amps at 476MHz

Hazards – RF BurnsMitigation – Avoid contact with center conductor of energized connectors. All employees working with LLRF systems are required to have the proper training.

110VAC ConnectorHazards - Shock Mitigation - Don’t touch conductors when plugging into outlet.All chassis are inspected by UL trained inspector.



April 20, 2006

Scope of Work – Injector Turn-onLinac Sector 0 RF Upgrade WBS 1.02.04.03.01

All 3 RF Chassis completed and InstalledControl Module ready for test – John Dusatko

Sector 20 RF distribution system WBS 1.02.04.03.02Phase and Amplitude Controllers (PAC) – 6 units in DesignPhase and Amplitude Detectors (PAD) – 1 unit in DesignPhased Locked Oscillator – Use SPPS unit for Turn OnLO Generator – Design 90% Complete and testedMultiplier – 476MHz to 2856MHz – Complete4 distribution chassis - CompleteLaser Phase Measurement – in Design – not required for turn on

LLRF Control and Monitor System WBS 1.02.04.03.031 kW Solid State S-Band Amplifiers – 5 units – in Fab, 2 donePAD – 12 units as above in designPAC – 6 units as above in designBunch Length Monitor Interface – awaiting Specs

Beam Phase Cavity WBS 1.02.04.03.04Will use single channel of PAD ChassisPill box cavity with 2 probes and 4 tuners - Complete next month



April 20, 2006

LCLS Layout

P. Emma



April 20, 2006

LLRF Control system spans Sector 20 off axis injector to beyond Sector 30



April 20, 2006

LCLS RF Jitter Tolerance BudgetLCLS RF Jitter Tolerance Budget

RMS tolerance budget for <12% rms peak-current jitter or

<0.1% rms final e− energy jitter. All tolerances are rms levels and the voltage and

phase tolerances per klystron for L2 and L3 are Nk larger,

assuming uncorrelated errors, where Nk is the number of

klystrons per linac.

P. Emma

Lowest Noise Floor Requirement 0.5deg X-Band = 125fSStructure Fill time = 100nSNoise floor = -111dBc/Hz @ 11GHz 10MHz BW-134dBc/Hz @ 476MHz

X-bandX-band XX--

0.500.50



April 20, 2006

Slow Drift Tolerance LimitsSlow Drift Tolerance Limits

Gun-Laser TimingGun-Laser Timing 2.4*2.4* deg-Sdeg-S

Bunch ChargeBunch Charge 3.23.2 %%

Gun RF PhaseGun RF Phase 2.32.3 deg-Sdeg-S

Gun Relative VoltageGun Relative Voltage 0.60.6 %%

L0,1,X,2,3 RF Phase (approx.)L0,1,X,2,3 RF Phase (approx.) 55 deg-Sdeg-S

L0,1,X,2,3 RF Voltage (approx.)L0,1,X,2,3 RF Voltage (approx.) 55 %%

(Top 4 rows for (Top 4 rows for // < 5%, bottom 4 limited by feedback dynamic range) < 5%, bottom 4 limited by feedback dynamic range)

* for synchronization, this tolerance might be set to * for synchronization, this tolerance might be set to 1 ps (without arrival-time measurement)1 ps (without arrival-time measurement)

(Tolerances are peak values, not rms)(Tolerances are peak values, not rms) P. Emma, J, WuP. Emma, J, Wu



April 20, 2006

Linac Sector 0 RF Upgrade

PEP PHASE SHIFT ON MAIN DRIVE LINE MDL RF with TIMING Pulse – Sync to DR

Master Oscillator is located 1.3 miles

from LCLS Injector

1.3 Miles to LCLS Injector

LCLS must be compatible with the existing linac operation including PEP timing shifts

MASTERAMPLIFIERS

MAIN LINAC (SECTOR 0) RF/TIMING SYSTEM

1

476MHzMASTEROSCILLATOR

PEP PHASESHIFTER+-720 Degreesin 0.5mS

SLC COUNTDOWNCHASSIS 476MHzDivide to 8.5MHz

Master TriggerGenerator MTGSyncs Fiducial to8.5MHz Damping Ringand 360Hz Power Line

8.5MHz

360Hz LineSync.

476MHz

360Hz

Fiducial GeneratorSyncronized to:360Hz Power Line8.5MHz Damping Ring476MHz RF Distribution

SumFiducialto RF

Main Drive Line (MDL)476MHz RF plus360Hz FiducialTo:Main Linac - 2 milesDamping RingsPEPNLCTAEnd Station AFFTBORION

Measurements on January 20, 2006at Sector 21show 30fS rms jitter in a bandwidth from 10Hz to 10MHz



April 20, 2006

Linac Sector 0 RF Upgrade Status

New Low Noise Master Oscillator – Done

New Low Noise PEP Phase ShifterRF Chassis – Done

Control Chassis – In Test

New Low Noise Master Amplifier – Done

Main Drive Line Coupler in Sector 21 – Done

Measurements Noise floor on 476MHz of -156dBc/Hz

Integrated jitter from 10Hz to 10MHz of 30fS



April 20, 2006

Sector 20 RF Distribution

Phase Critical Cables

Laser <140ft < 700fSpp

Gun < 100ft < 400fSpp

RF CONTROLOffset adjust

2830.5MHz LO Gen

RF MONITOR119MHz Phase

119MHz

Main Drive Line (MDL)476MHz RF360Hz FiducialFrom Sector 0 (2km)

RF HUT Coupler476MHz Ref. 100uW

LASER

LCLS 476MHz PLL

LCLS Sector 20 RF Reference System

4x 476MHz13dBm OUT

TIMING SYSTEMFIDO

476MHz to 2856MHzMULTIPLIER

120HzTRBR

2856MHz16 Way Distribution20dBm each

+13dBm in

2856MHzLASER DiodePhase NoiseMeasurement

Track/HoldTRBR

+7dBm

+17dBm

2856MHz2Watt Amplifier

102MHzDigitizer Clocks16 Way Distribution20dBm each Gun

L0AL0BL0TCAVL1SL1X

476MHzLASER LOCKReference

RF MONITOR

119MHz0dBm OUT

Diode Detector

LASER DiodeOutput

IQ Modulator ControlMixer Monitor

102MHz2Watt Amplifier

RF MONITOR

RF CONTROLIQ Modulator

LO Phase Monitor

Sample and Hold PLLwith DAC offset adjustand Error Monitor

GunL0AL0BL0TCAVL1SL1XLINACEXPERIMENTS

2856MHz


2830.5MHz2Watt Amplifier

2830.5MHz LO16 Way Distribution20dBm each

476MHz to 2856MHzMULTIPLIER

GunL0AL0BL0TCAVL1SL1X

2856MHz in

IQ Modulator to adjust2830.5MHz to 2856MHz Phase

Divide 112 to 25.5MHzSSB Mix to 2830.5MHz4X to 102MHz

25.5MHz out

102MHz out 2830.5MHz out

Diode Detector


Diode Detector


LO Phase Monitor

+13dBm in

+7dBm

LO Phase Monitor

+17dBm

RF MONITOR


MDL to Linac Sectors 21 to 30PEP and Research Yard

RF MONITOR

FSJ4-50 0.8dB/30ft

2856MHz from Sector 21



April 20, 2006

Sector 20 RF Distribution System StatusPhase Locked Oscillator – 476MHz

Initial Turn On use SPPS OscillatorMay modify control to achieve better stability during 2007

LO Generator – 2830.5MHzDesign complete – Prototype tested – 25MHz SSB modulator board done2856MHz IQ Modulator prototype near completion

Multipliers - 476MHz to 2856MHz – DonePhase and Amplitude Control (PAC) Unit

In Design – IQ Modulators and Amplifiers selected – See Next Section

Phase and Amplitude Detector (PAD) UnitIn Design – Testing Mixers, Amplifiers, Filters – See Next Section

Amplifiers – not ordered yetLaser Phase Measurement System – Design Started



April 20, 2006

LLRF Control System

Distributed Control System

Microcontroller based IOC Control and Detector Modules

Ethernet Switch

Central Feedback Computer



April 20, 2006

LLRF Control and Monitor System Klystron Station

13dBm

17dBm

SPARE

KLYSTRON STATION

23dBm

240ft = 17dB 1/2 Superflex= 10dB LDF4

240ft = 2.5dB 1/2 Superflex= 1.6dB LDF4= 3dB LDF1

3dBm

3dBm

140ft = 25dB 3/8 Superflex

Coupled Out

ENET

TRIG

TRIG

ENETLCLS RF HUT2830.5MHz LOAmp / Splitter

TCAV

RF Gun

L0A

L0B

L1S

L1X

RF HUT

PAC

20-5

20-6

20-7

20-8

21-1

21-2

LCLS RF HUT2856MHz RFAmp / Splitter

TCAV

RF Gun

L0A

L0B

L1S

L1X

20-5

20-6

20-7

20-8

21-1

21-2

LCLS RF HUT102MHz ClockAmp / Splitter

TCAV

RF Gun

L0A

L0B

L1S

L1X

20-5

20-6

20-7

20-8

21-1

21-2

PAD

In 2856MHz Out

102MHz Clock In

Trig & Ethernet

SSSB

102MHzClock In Out

LO

Trig & Ethernet

To IPAKlystron Drive

In 2856MHz Out

SSSB Control Control & TRIG

From Klystron Drive Coupler

KLY BEAM Voltage

PAC OUT

Coupled Out



April 20, 2006

LLRF Control and Monitor System Status

1 kW Solid State S-Band Amplifiers – 5 units1kW amplifier modules currently in test

Existing amplifier support design under review

Phase and Amplitude Detectors – 11 dual chan unitsPreliminary Design Complete

Evaluating amplifiers, mixers, and filters

Phase and Amplitude Controllers – 6 single chan unitsPreliminary design complete

Evaluating mixers and amplifiers

Bunch Length Monitor InterfaceNeed Specifications



April 20, 2006

Beam Phase Cavity Status

Electronics will use single channel of PAD ChassisPill box cavity with 2 probes and 4 tuners

Cavity Electronics will use single channel of RF MonitorCavity in fabricationComplete – May 2006Bake – June 2006

Measurement of beam phase to RF reference phase. The result will be used to correct timing of laser to RF reference. Cavity is located between L0A and L0B.



April 20, 2006

Controls Engineering Requirements

When beam is present, control will be done by beam-based longitudinal feedback (except for T-cavs); when beam is absent, control will be done by local phase and amplitude controller (PAC)

Adhere to LCLS Controls Group standards: RTEMS, EPICS, Channel Access protocol

Ref: Why RTEMS? Study of open source real-time OS

Begin RF processing of high-powered structures June 2006



April 20, 2006

External Interfaces

LLRF to LCLS global control system PVs available for edm screens, archiving, etc over controls network

LLRF VME to beam-based longitudinal feedback from feedback: phase and amplitude corrections at 120 Hz over private ethernet from LLRF: phase and amplitude values

(internal) LLRF VME to LLRF microcontrollers from VME: triggers, corrected phase and amplitude from microcontrollers: phase and amplitude averaged values at 120 Hz, raw phase and amplitude values for diagnostics



April 20, 2006

Sector 20 PAC and PAD Control

VME IOC

Ethernet Switch

Arcturus Coldfire13 PADs

FIFO

ADC

13 PACsFPGA

DAC



April 20, 2006

EPICS PANELS

Single Pulse Diagnostic Panels for PADs are RunningRemaining Software

History Buffer Select PVsMulti pulse data analysis, correlation plotsLocal RF Feedback loopsLinks to global Feedback loops



April 20, 2006

RF Status SummaryLinac New Low Noise Source – RF components installed, Controls Feb06RF Distribution – Prototyping underway (R. Akre, B.Hong, H. Schwarz)Monitor Controller Board (J. Gold, R. Akre, Till Straumann)

Single channel prototype for ADS5500 tested to specificationsFour channel ADS5500 board – layout complete (SNR 70dBFS)Switched to LTC2208 16bit 130MSPS ADC (Prototype in test) (SNR 77dBFS)

RF Monitor Board in preliminary design (H. Schwarz, B.Hong)Testing mixers

Control Boards (J. Olsen)Fast Control Board – All but slow ADCs for temp and voltages tested and low level drivers writtenSlow control board – use fast board

RF Control Board in preliminary design (H. Schwarz, B. Hong)Software (D. Kotturi, Till Straumann)

EPICS on RTEMS on Microcontroller doneDrivers – data collection interrupt routine doneAlgorithms – PAD 90% complete PAC in progressCalibration routines – Need specificationsCollision free Ethernet



April 20, 2006

LLRF ScheduleRF Distribution Design Complete May 2006RF Hut Distribution System installed August 2006PAC design Complete June 2006PAD design Complete July 2006PAC and PAD minimal operational software completeEthernet testing with multiple PACs and PADs???Single S-Band station – hardware installed Sept 20064 other S-Band Stations – November 2006Feedback software interfacing???Test and debug with Klystrons On – December 2006X-Band Station January 2007



April 20, 2006

End of LLRF RF TalkBackup for RF Talk

Mostly Correct



April 20, 2006

DESIGN PHILOSOPHY

Reliability is inversely proportional to the number of connectors.

Stability is inversely proportional to the number of connectors.

Measurement accuracy is inversely proportional to the number of connectors and the amount of Teflon,which is typically found in connectors.

Cost of maintenance is proportional to the number of connectors.



April 20, 2006

Electro-Optical SamplingElectro-Optical Sampling

170 fs rms170 fs rms

Single-ShotSingle-Shot

Timing JitterTiming Jitter(20 Shots)(20 Shots)

200 200 m thick ZnTe crystalm thick ZnTe crystal

ee

Ti:Sapphire Ti:Sapphire laserlaser

Adrian Cavalieri et al., Adrian Cavalieri et al., U. Mich.U. Mich.

<300 fs<300 fs

ee temporal information is encoded on temporal information is encoded on transverse profile of laser beamtransverse profile of laser beam



April 20, 2006

MPS – PPS Issues Addressed by Controls Group

Not Reviewed Here Vacuum

New vacuum system summary to be fed to each klystron existing MKSU.

PPS SystemInjector modulators will be interlocked by Injector PPS system.PPS requirements for radiation from the injector transverse accelerator needs to be determined. Radiation levels will be measured during testing in the Klystron Test Lab – Feb 06.



April 20, 2006

Bandwidth of S-Band System

Upper Frequency Limit – 10MHzBeam-RF interaction BW due to structure fill time

< 1.5MHz S-Band Accelerators and Gun

~10MHz X-Band and S-Band T Cav

Structure RF Bandwidth ~ 16MHz

5045 Klystron ~ 10MHz

Lower Frequency Limit – 10kHzFill time of SLED Cavity = 3.5uS about 100kHz

Laser – Needs to be measured ~ 10kHz



April 20, 2006

Noise LevelsRF Reference Single Side Band (SSB) Noise Floor

2856MHz RF Distribution -144dBc/Hz-174dBc/Hz @ 119MHz (24x = +28dB +2 for multiplier)

2830.5MHz Local Oscillator -138dBc/Hz

Integrated Noise-138dBc/Hz at 10MHz = -65dBc = 32fS rmsSNR = 65dB for phase noise

Added noise from MIXER (LO noise same as RF)SNR of 62dB

ADC noise levelsSNR of 70dB – 14bit ADS5500 at 102MSPS



April 20, 2006

Phase Noise – Linac Sector 0

OLD MASTER OSCILLATOR-133dBc/Hz at 476MHz 340fSrms jitter in 10MHz BW

NEW MASTER OSCILLATOR-153dBc/Hz at 476 MHz34fSrms jitter in 10MHz BW

Integrated Noise - Timing Jitter fs rmsIntegral end 5MHz 10kHzIntegral start 1M 100k 10k 1k 100 10Aug 17, 2004Sector 30 27 30 33 38 75 82Jan 20, 2006Sector 21 15 19 20 20 8 17



April 20, 2006

Sector 20 RF Distribution Cable ErrorsTemperature Coefficient of 2.8ppm/ºF and Cable length is 1200ºS/ftAll Cables except LASER are less than 100ft

Distances feet and errors in degrees S total range

RF Hut Down Linac Wall Injector TotalUnit Ft degS ft degS ft degS ft degS ft degS DegSLaser 8 0.054 25 0.017 10 0.014 10 0.007 85 0.58 0.68Gun 8 0.054 25 0.017 10 0.014 10 0.007 40 0.27 0.37L0-A 8 0.054 25 0.017 10 0.014 10 0.007 30 0.21 0.31B Phas 8 0.054 25 0.017 10 0.014 10 0.007 20 0.14 0.24L0-B 8 0.054 25 0.017 10 0.014 10 0.007 20 0.14 0.24L0-T 8 0.054 25 0.017 10 0.014 10 0.007 10 0.07 0.17L1-S 8 0.054 25 0.017 50 0.068 0.14L1-X 8 0.054 25 0.017 60 0.081 0.16Temperature Variations: RF Hut ±1ºF : Penetration ±0.1ºF : Linac : ±0.2ºF

Shield Wall ±0.1ºF : Injector ±1ºF



April 20, 2006

RF System Topology / Specifications

476MHz PLL2830.5MHz LOAmp / Splitter

Laser

RF Gun

L0A

Phase Cavity

L0B

L1S

L1X

L2 Ref

PAD

Laser

RF Gun

L0A

Phase Cavity

L0B

L1S

L1X

L2 Ref

Most Devicesare in tunnel

Laser

RF Gun

L0A

Phase Cavity

L0B

L1S

L1X

L2 Ref

1

Number of cables per deviceReference cables are8ft and can drift +-50fS

1

2

4

2

2

2

5

RF HUT

+-240fS

+-310fS

+-370fS

+-680fS

+-500fS

+-160fS

+-140fS

+-240fS

Cable Drift Based onTemperature variationsand temp co of 5ppm/degC

LinacSector 0 RF

MDL

L2 - 4 SectorsSpecifications70fS rms jitter+-5pS drift

L3 - 6 SectorsSpecifications150fS rms jitter+-5pS drift

L0, L1 - 5 KlystronsSpecifications100fS rms jitter+-2.3pS drift



April 20, 2006

RF Monitor Signal CountsADC Chan Cnt Chassis

Count/LocationDistribution (5~2850MHz, 4<500MHz) 4 1HutRF Gun 9 1Kly 1.5HutBeam Phase Cavity 2 0.5HutL0-A Accelerator 4 1Kly 0.5HutL0-B Accelerator 4 1Kly 0.5HutL0-T Transverse Accelerator 4 1Kly 0.5HutL1-S Station 21-1 B, C, and D Acc 6 1Kly 1.0HutL1-X X-Band accelerator X-Band 5 1Kly 0.5HutS25-Tcav 4 1KlyS24-1, 2, & 3 Feedback 0S29 and S30 Feedback 0

Total Chassis 7Kly 6HutTotal into Hut IOC 12



April 20, 2006

RF Control Signal CountsDistribution (3~2850MHz, 3<500MHz) 6 IQ ModRF Gun 1 Klystron Beam Phase Cavity 1 IQ modL0-A Accelerator 1 KlystronL0-B Accelerator 1 KlystronL0-T Transverse Accelerator 1 KlystronL1-S Station 21-1 B, C, and D accelerators 1 Klystron

L1-X X-Band accelerator X-Band 1 IQ ModS25-Tcav 1 KlystronS24-1, 2, & 3 Feedback 3 KlystronsS29 and S30 Feedback 2 IQ modulators 476MHz

Total modulators 11 Fast 8 Slow 19 modulatorsTotals at ~2856MHz 14 modulatorsTotal into Hut IOC 14 modulators



April 20, 2006

LLRF Control and Monitor System

LLRF Control and Monitor System1 kW Solid State S-Band Amplifiers – 5 units

Phase and Amplitude Monitors – 12 units

Phase and Amplitude Controllers – 6 units

Bunch Length Monitor Interface – Need Specifications



April 20, 2006

RF Control

RF Control Module consist of the following:

Input Coupler, IQ Modulator, Amplifier, Output Coupler

Filters for I and Q inputs

I

RFLO

Q

1

2

34

BXMP1007

2856MHz Input Monitor 2856MHz Output Monitor

Q Control

RF InRF Out

I Control

17dBm 0dBm

2850MHz IQ Modulator

17dBm

Required 13 UnitsIncludes Distribution



April 20, 2006

RF MonitorRequired 13 Chassis for Injector – Includes DistributionLO 2830.5MHz : RF 2856MHzIF 25.5MHz (8.5MHz x 3 in sync with timing fiducial)Double-Balanced MixerMixer IF to Amp and then Low Pass FilterFilter output to ADC sampling at 102MSPS

MIXER

LOR

F IF

Amplifier

25.5MHz BP FILTER

2830.5MHz Local Osc.

2856MHz RF Signal

To ADC

LTC2208 SNR = 77dBFS

102MSPS



April 20, 2006

1 kW Solid State S-Band Amplifiers

Design Complete Two Units on the ShelfModules in house – and testedSupport parts – Some parts in house

Power Supplies, relays, chassis on order



April 20, 2006

SLAC Linac RF – New ControlThe new control system will tie in to the IPA Chassis with 1kW of drive power available. Reference will be from the existing phase reference line or the injector new RF reference

I and Q will be controlled with a 16bit DAC running at 119MHz. Waveforms to the DAC will be set in an FPGA through a microcontroller running EPICS on RTEMS.

Existing System Accelerator

Klystron

Next Sector

MDL 476MHz

SubBooster

6 X2856MHz

Sub Drive Line

High PowerPhase ShifterAttenuator

SLED

Phase &AmplitudeDetector

ExistingPhaseReferenceLine

-45dB200MW

3kW

20mW

1W1mW

To NextKlystron

I

RF LO

Q

1

2

3

4

IQ Modulator

1kW Amp2856MHz

IPA



April 20, 2006

Controls Talk



April 20, 2006

LLRF Controls

OutlineRequirementsExternal InterfacesSchedule

Date NeededPrototype Completion DateHardware Order DateInstallationTest Period

Design Design Maturity (what reviews have been had) State of Wiring Information State of Prototype



April 20, 2006

Requirements

At 120 Hz, meet phase/amp noise levels defined as:

0.1% rms amplitude 100 fs rms in S-band (fill time = 850 ns) 125 fs rms in X-band (fill time = 100 ns)All tolerances are rms levels and the voltage and phase tolerances per klystron for L2 and L3 are Nk larger, assuming uncorrelated errors, where Nk is the number of klystrons per linac (L2 has 28; L3 has 48)



April 20, 2006

Engineering Requirements

When beam is present, control will be done by beam-based longitudinal feedback (except for T-cavs); when beam is absent, control will be done by local phase and amplitude controller (PAC)

Adhere to LCLS Controls Group standards: RTEMS, EPICS, Channel Access protocol

Ref: Why RTEMS? Study of open source real-time OS

Begin RF processing of high-powered structures May 20, 2006



April 20, 2006

External Interfaces

LLRF to LCLS global control system PVs available for edm screens, archiving, etc over controls network

LLRF VME to beam-based longitudinal feedback from feedback: phase and amplitude corrections at 120 Hz over private ethernet from LLRF: phase and amplitude values

(internal) LLRF VME to LLRF microcontrollers from VME: triggers, corrected phase and amplitude from microcontrollers: phase and amplitude averaged values at 120 Hz, raw phase and amplitude values for debug



April 20, 2006

External Interfaces: Laser - Tcav

I and Q Demo-dulator

CPU

FIFOs

DAC

slow

Temperature monitors

EVR

Laser and RF ref

L0-AL0-B

L1-SL1-X

T Cav

gun

Controls gigabit ethernet (interface to MCC)

Private ethernet8 kBytes at 120 Hz

PAD

ADC

FPGADAC

1 trigger for 4

channels of 1k

samples


In-house modules sharing VME crate for timing triggers

476 MH

z RF R

eferen

ce clo

ck dis

tribute

d to all

30 se

ctors i

n the L

inac a

nd bey

ond

RF Reference/4 = 119 MHzstabilized to 50 fs jitter

RF Reference*6 = 2856 MHzstabilized to 50 fs jitter

Coldfire CPU

running RTEMS

and EPICS

Coldfire CPU

running RTEMS

and EPICS

PAC

RF Phase and Amplitude correction at 120 Hz for:laser, gun, L0-A, L0-B, L1-S, L1-X, T cav

10' accelerator

IQ Modulator gives phase

and amplitude control

1 kW 1 kW

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

DAC

slow

VME Crate at S20 running

longitudinal, beam-based

feedback

Private ethernet



April 20, 2006

External Interfaces: L2-L3

I and Q Demo-dulator

CPU

FIFOs

DAC

slow

Temperature monitors

EVR

Laser and RF ref

L0-AL0-B

L1-SL1-X

T Cav

gun

Controls gigabit ethernet (interface to MCC)


PAD

ADC

FPGADAC

1 trigger for 4

channels of 1k

samples


In-house modules sharing VME crate for timing triggers

476 MH

z RF R

eferen

ce clo

ck dis

tribute

d to all

30 se

ctors i

n the L

inac a

nd bey

ond

RF Reference/4 = 119 MHzstabilized to 50 fs jitter

RF Reference*6 = 2856 MHzstabilized to 50 fs jitter

Coldfire CPU

running RTEMS

and EPICS

Coldfire CPU

running RTEMS

and EPICS

PAC

RF Phase and Amplitude correction at 120 Hz for:laser, gun, L0-A, L0-B, L1-S, L1-X, T cav

10' accelerator

IQ Modulator gives phase

and amplitude control

1 kW 1 kW

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

DAC

slow



feedback

Private ethernet



April 20, 2006

DesignDesign maturity (what reviews have been had):

RF/Timing Design, DOE Review, August 11, 2004 Akre_FAC_Oct04_RF_Timing, FAC Review, October, 2004 Low Level RF Controls Design, LCLS Week, January 25-27, 2005 Low Level RF, Lehman Review, May 10-12, 2005 LLRF Plans for Development and Testing of Controls, LCLS Week, July 21, 2005 Low Level RF Design, Presentation for Controls Group, Sept. 13, 2005 LLRF Preliminary Design review, SLAC, September 26, 2005 LCLS LLRF Control System - Kotturi, LLRF Workshop, CERN, October 10-13, 2005 LCLS LLRF System - Hong, LLRF Workshop, CERN, October 10-13, 2005 LLRF and Beam-based Longitudinal Feedback Readiness - Kotturi/Akre, LCLS Week, SLAC, October 24-26, 2005 LCLS Week LLRF and feedback - Kotturi/Allison, LCLS Week, SLAC, October 24-26, 2005 LLRF, LCLS System Concept Review/Preliminary Design Review, SLAC, November 16-17, 2005 Comments LLRF Beam Phase Cavity Preliminary Design review, SLAC, November 30, 2005

Docs at: http://www.slac.stanford.edu/grp/lcls/controls/global/subsystems/llrfState of wiring: percent complete Captar input will be given at time of presentation State of prototype: PAD (1 chan ADC) and PAC boards built (shown on next pages).Testing.



April 20, 2006

PAD – the monitor board



April 20, 2006

PAD – the monitor board

2 X 16 bit ADC119 or 102MHz ClockLTC2208Transformer Coupled Inputs

Chan. 2

Chan. 1

FIFO 2 X 1k words

WCLK

16bit DATA

16bit DATA

WCLK

RF CHAN 1INPUT

RF CHAN 2INPUT

Line DriversFilters

MIXER

LORF

IF

MIXER

LORF

IF

RF Board

25.5MHz IF

Control Board

Control

EXTERNALTRIGGER120Hz

EXTERNALCLOCK102MHz

CS/CLK

16 bitDATA

CONTROL /Arcturus uC5282Microcontroller Modulewith 10/100 Ethernet

ET

HE

RN

ET

LO INPUTRF - 25.5MHz

CPLD



April 20, 2006

PAC – the control board



April 20, 2006

PAC – the control board

SSSBChassis

Temperature MonitorForward Power 0-?VReflected Power 0-?VOver Temp 0 or 12V Power Supplie +12VPower Supply -12V

I

R F L O

Q

I&Q MODULATOR

1

2

3

4

MAX58752 X 16 bit DAC119MHz Clock(1MHz to 200MHz)

I

Q

XILINXSPARTAN 3FPGA

16bit DATA

CS/CLK

16bit DATA

16 bitDATA

CLK

CLK CONTROL /Arcturus uC5282Microcontroller Modulewith 10/100 Ethernet

ET

HE

RN

ET

Control Control

RF OUTPUTTo SSSB

TRIGGERMonitor TTL

EXTERNALTRIGGER120Hz60nS NIM

2856MHz Ref

MONITORPORTS

AD8099 Diff Amp

SSSBTrigTTL17 to 30uS

Thermocouples

CLOCK119MHz

RF BOARD

t

MATCHINGFILTERNETWORK

TemperatureMonitor t

DC PowerSupplies

DC PowerSupplyMonitors

Control BoardADCs

TemperatureMonitor



April 20, 2006

Additional Slides

The following two pages show an overview of the LLRF control modules. From these diagrams, counts of module types, as well as function and location are seen.



April 20, 2006

Eth recvr

EVR



feedback.

CPU

PAC

Gun

PADPADPAD

SPAC

RF Dist’n

Laser

PAC

L0-B

PADPAD

PAC

L1-S

PADPAD

PACL0-Tcav

PADPAD

PACL0-A

PADPAD

SPAC

PAD

PAD PAC

Beam Phase Monitor

PAD

SPACSPACSPAC

SPACPAD

Fast PACs: Slow PACs (SPACs): PADs: VME crates:

RF phase and amplitude correction and global feedback at 120 Hz for LCLS LINAC S20

PAC

L1-X

PADPADPAD

PAD

PAC

Key:

Indicates may be needed

86191

S20

The maybe is included in counts below

Indicates located in RF HutOtherwise at Klystron

Overview of LLRF at Sector 20



April 20, 2006

Overview of LLRF at Sector 24

Fast PACs: Slow PACs (SPACs): PADs: VME crates:

Eth recvr

EVR

CPU

PAC

L24-1

PACL24-2

PACL24-3

PACTcav L24-8

SPAC

S29

SPAC

S30

PADPAD



feedback.

4221

S24

RF phase and amplitude correction and global feedback at 120 Hz for LCLS LINAC S20



April 20, 2006

Beam Phase MonitorR. Akre

A. Haase

B. Hong

D. Kotturi

V. Pacak

H. Schwarz

Preliminary Design Review

November 30, 2005



April 20, 2006

Outline

•Purpose

•Specifications

•System outline

•Cavity

•Noise Levels

•Analysis

•Long Term Drifts

•Summary



April 20, 2006

Laser Timing Stabilization Feedback

Beam timing information from the beam phase monitor will be used to apply corrections to the timing of the laser on the RF Gun.

PHAS AMPL

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 Oscilla tor

LINAC MDL Ref.

GUN RF REF.

LASER RF R EF.

PHAS

PHASEERROR

ActuatorL0, L1 to L2, L3Phase

LASER POWERACTUATOR

OUT

GUN-CELL2

GUN-CELL1

KLYSTRONAMPLIFIER / SLC CONTROL

LASER OSC

Reference

LASER PHASE & AMPLITUDE?

LASER AMPLIFIER

LASER OSC. PHASE

WATER TEMP

RF GUN

LASER PHASE ACTUATOR

LASER OSCILLATOR PHASEFEEDBACK

InputsBEAM PHASE CAVITY

ActuatorsLASER PHASE ACTUATOR

PHASE ERROR BetweenL0, L1 and L 2, L3

AMPL

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

GUN TUNE FEEDBACK

InputsGUN-FOR-PHASGUN-CELL1-PHASGUN-CELL2-PHAS

ActuatorsWATER TEMP

GUN-FOR

2856MHzRF REF.

LASER

GUN

L0A

L0B

L0-TCAV1

L1-X

L1-S



April 20, 2006

Specifications

Short term (2 second) timing jitter: 100fS rms

Long term (4 day) timing jitter: ±1pS

Range of the above accuracies is ±10pS

Data available at 120Hz



April 20, 2006

System Outline



April 20, 2006

Cavity

Frequency = 2856MHz

Q = 6000

Time Constant = 700nS

Temperature Coefficient = 50kH/°C



April 20, 2006

System Critical Noise Levels and Bandwidths

Cavity Signal – Bandwidth 500kHz

Local Oscillator – Noise Floor –143dBc/Hz

IF Filter – Bandwidth 4MHz

ADC – SNR at input 76dB



April 20, 2006

System Critical Noise Levels and Bandwidths

2830.5MHz Oscillator

1

Beam Phase Cavity

Attenuator

Monitor Port

Coupler

MIXER

LO

RF

IF

Monitor Port

In TunnelAmp

Filter - Butterworth3rd order BandPass2.5.5MHz Center4.0MHz BW2dB IL at 25.5MHz

30dBm pk

ADC LTC22082.25Vpp FSTransformer coupled102MHz Clock

30dBm pk

Attenuator

3dBm pk23dBm pk

2Vpp 10dBm pk

13dBm

-3dBm pk 17dBm pk

-130dBm/Hz-143dBc/Hz

-174dBm/Hz-174dBm/Hz

-129dBm/Hz-143dBc/Hz

-146dBm/Hz-143dBc/Hz Within filters BW

-135dBm/Hz-143dBc/HzBeyond 5MHz from CF<-155dBm/Hz<-163dBc/HzIntegrated Noise-77dBc

Generated from 119MHz OscillatorExpected SSB Phase Noise LevelsOffset Hz dBc/Hz @ 2830.5MHz10 -82100 -961k -12410k -14420k -146

ADC SNR 77dBFS



April 20, 2006

ADC Linear Technologies LTC2208

16Bit 130MHz

SNR 77.6dBFS 30MHz in Clock 130MHz SFDR 95dB



April 20, 2006

AnalysisPhas

e

Calculated Beam Phase at Beam Time

Measured Data Point 1

Measured Data Point 2

Time



April 20, 2006

I & Q from WaveformDigital Down Mixing and Normalization

0 10 20 30 40 50 600.6

0.4

0.2

0

0.2

0.4

0.6

0.8

125.5MHz Digitized Signal

Point Number

Fra

ctio

n A

DC

Ful

l Sca

le

.

Digitized

Input Signal



April 20, 2006

Optimization

Optimal Points to use for analysis is 16 point average at points 18 and 120



April 20, 2006

Analysis Results

Standard deviation of result = 1.1e-4 or 6.3fS rms jitter

Signal level 20dB lower will give 63fS rms jitter

Sensitivity to frequency change = 0.6fS/2.8kH freq change

Sensitivity to timing change over +-10deg = 1:1



April 20, 2006

80ft (1M deg) of ½ inch superflex has TC of 4ppm/degCWater temp tolerance is +-0.1degF = +-400fS drift

Long Term Drifts



April 20, 2006

Summary

Short term (2 second) timing jitter: 100fS rms

63fS rms

Long term (4 day) timing jitter: ±1pS

±0.8pS

Range of the above accuracies is ±10pS

Results

Data available at 120Hz

Simple algorithm in integer arithmetic will allow this



April 20, 2006

Feedback Page 1

LOCAL FEEDBACK

LOCAL FEEDBACK



April 20, 2006

Feedback Page 2

LOCAL FEEDBACK

GLOBAL FEEDBACK



April 20, 2006

Feedback Page 3LOCAL FEEDBACK

LOCAL FEEDBACK

GLOBAL FEEDBACK



April 20, 2006

Feedback Page 4GLOBAL FEEDBACK



April 20, 2006

Feedback Page 5GLOBAL FEEDBACK



April 20, 2006

Feedback Page 6

Documents

Ron Akre, Dayle Kotturi LCLS [email protected]@slac.stanford.edu, [email protected]@slac.stanford.edu April 20, 2006 Linac Coherent