1. Linac Coherent Light Source (LCLS) Low Level RF System Injector Turn-on December February 8, 2006

2. Safety First and Second and Third…..to Infinity
Hazards in the LLRF system
RF 1kW at 120Hz at 5uS = 0.6 Watts average,
2 Watt average amps at 2856MHz,
60W average amps at 476MHz
Hazards – RF Burns
Mitigation – Avoid contact with center conductor of energized connectors. All employees working with LLRF systems are required to have the proper training.
110VAC Connector
Hazards - Shock
Mitigation - Don’t touch conductors when plugging into outlet.
All chassis are inspected by UL trained inspector.

3. Scope of Work – Injector Turn-on
Linac Sector 0 RF Upgrade WBS
All 3 RF Chassis completed and Installed
Control Module to be installed Feb 06
Sector 20 RF distribution system WBS
Phase and Amplitude Controllers – 9 units
Phase and Amplitude Monitors – 2 dual channel units
Phased Locked Oscillator
LO Generator
Multiplier – 476MHz to 2856MHz – 2 units
Amplifiers – 4 units
Laser Phase Measurement
LLRF Control and Monitor System WBS
1 kW Solid State S-Band Amplifiers – 5 units
Phase and Amplitude Monitors – 16 dual chan units
Phase and Amplitude Controllers – 6 single chan units
Bunch Length Monitor Interface
Beam Phase Cavity WBS
Will use single channel of RF Monitor Chassis
Pill box cavity with 2 probes and 4 tuners
52 Chassis Total
9 Chassis Completed

4. LCLS Layout
P. Emma

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

6. LCLS RF Jitter Tolerance Budget
Lowest Noise Floor Requirement
0.5deg X-Band = 125fS
Structure Fill time = 100nS
Noise floor = 11GHz 10MHz BW
476MHz
X-band X-
0.50
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

7. Slow Drift Tolerance Limits
(Top 4 rows for De/e < 5%, bottom 4 limited by feedback dynamic range)
Gun-Laser Timing
2.4*
deg-S
Bunch Charge
3.2 %
Gun RF Phase
2.3
Gun Relative Voltage
0.6
L0,1,X,2,3 RF Phase (approx.) 5
L0,1,X,2,3 RF Voltage (approx.)
(Tolerances are peak values, not rms)
P. Emma, J, Wu
* for synchronization, this tolerance might be set to 1 ps (without arrival-time measurement)

8. Linac Sector 0 RF Upgrade
LCLS must be compatible with the existing linac operation including PEP timing shifts
Master Oscillator is located 1.3 miles from LCLS Injector
1.3 Miles to LCLS Injector
Measurements on January 20, 2006 show 30fS rms jitter in a bandwidth from 10Hz to 10MHz
PEP PHASE SHIFT ON MAIN DRIVE LINE
MDL RF with TIMING Pulse – Sync to DR

9. Linac Sector 0 RF Upgrade Status
New Low Noise Master Oscillator – Done
New Low Noise PEP Phase Shifter
RF Chassis – Done
Control Chassis – Feb 06
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

10. Sector 20 RF Distribution
Phase Critical Cables
Laser <140ft < 700fSpp
Gun < 100ft < 400fSpp

11. Sector 20 RF Distribution System Status
Phase Locked Oscillator – 476MHz
Preliminary Design – same as SPPS
Low Noise 119MHz VCO and Multipliers in house
Analog Track/Hold / feedback amp complete unit tested at SPPS
May consider digital feedback amp if time permits
LO Generator – MHz
Preliminary Design complete – 80% of Parts are in house
PC Board in design
Multipliers - 476MHz to 2856MHz – Done
Phase and Amplitude Control Unit
In Design – Testing IQ modulators and amplifiers – See Next Section
Phase and Amplitude Monitor Unit
In Design – Testing Mixers, Amplifiers, Filters – See Next Section
Amplifiers – not ordered yet
Laser Phase Measurement System – Design Started

12. Distributed Control System
LLRF Control System
Distributed Control System
Microcontroller based IOC Control and Monitor Modules
Central Feedback Computer
See LLRF Control talk
Control breakout session – Attached
By Dayle Kotturi

13. LLRF Control and Monitor System Status
1 kW Solid State S-Band Amplifiers – 5 units
1kW amplifier modules currently in test
Existing amplifier support design under review
Phase and Amplitude Monitors – 16 dual chan units
Preliminary Design Complete
Evaluating amplifiers, mixers, and filters
Phase and Amplitude Controllers – 6 single chan units
Preliminary design complete
Evaluating mixers and amplifiers
Bunch Length Monitor Interface
Need Specifications

14. Beam Phase Cavity Status
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.
Electronics will use single channel of RF Monitor Chassis
Pill box cavity with 2 probes and 4 tuners
Cavity Electronics will use single channel of RF Monitor
Cavity in design - probe and tuner design complete
Fab, Test, Tune – May 2006
Bake – June 2006

15. Status Summary
Linac New Low Noise Source – RF components installed, Controls Feb06
RF 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 specifications
Four channel ADS5500 board – layout complete (SNR 70dBFS)
Switched to LTC bit 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 – in test
Slow control board – May use fast board
RF Control Board in preliminary design (H. Schwarz, B. Hong)
Software (D. Kotturi, Till Straumann)
EPICS on RTEMS on Microcontroller done
Drivers
Algorithms
System Completion - December 2006 for Injector

16. End of LLRF RF Talk Backup for RF Talk

17. MPS – PPS Issues Addressed by Controls Group Not Reviewed Here
Vacuum
New vacuum system summary to be fed to each klystron existing MKSU.
PPS System
Injector 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.

18. Bandwidth of S-Band System
Upper Frequency Limit – 10MHz
Beam-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 – 10kHz
Fill time of SLED Cavity = 3.5uS about 100kHz
Laser – Needs to be measured ~ 10kHz

19. Noise Levels RF Reference Single Side Band (SSB) Noise Floor
2856MHz RF Distribution -144dBc/Hz
119MHz (24x = +28dB +2 for multiplier)
2830.5MHz Local Oscillator -138dBc/Hz
Integrated Noise
-138dBc/Hz at 10MHz = -65dBc = 32fS rms
SNR = 65dB for phase noise
Added noise from MIXER (LO noise same as RF)
SNR of 62dB
ADC noise levels
SNR of 70dB – 14bit ADS5500 at 102MSPS

20. Phase Noise – Linac Sector 0
OLD MASTER OSCILLATOR
-133dBc/Hz at 476MHz 340fSrms jitter in 10MHz BW
NEW MASTER OSCILLATOR
-153dBc/Hz at 476 MHz
34fSrms jitter in 10MHz BW
Integrated Noise - Timing Jitter fs rms
Integral end 5MHz kHz
Integral start 1M 100k 10k 1k
Aug 17, 2004
Sector
Jan 20, 2006
Sector

21. Sector 20 RF Distribution Cable Errors
Temperature Coefficient of 2.8ppm/ºF and
Cable length is 1200ºS/ft
All Cables except LASER are less than 100ft
Distances feet and errors in degrees S total range
RF Hut Down Linac Wall Injector Total
Unit Ft degS ft degS ft degS ft degS ft degS DegS
Laser
Gun
L0-A
B Phas
L0-B
L0-T
L1-S
L1-X
Temperature Variations: RF Hut ±1ºF : Penetration ±0.1ºF : Linac : ±0.2ºF
Shield Wall ±0.1ºF : Injector ±1ºF

22. RF Control and Monitor Signal Counts
Distribution (5~2850MHz, 4<500MHz) 9 IQ Mod 4 RF monitors
RF Gun 1 Klystron 7 RF monitors
Beam Phase Cavity 1 IQ mod 2 RF monitor
L0-A Accelerator 1 Klystron 4 RF monitors
L0-B Accelerator 1 Klystron 4 RF monitors
L0-T Transverse Accelerator 1 Klystron 4 RF monitors
L1-S Station 21-1 B, C, and D accelerators
1 Klystron 6 RF monitors
L1-X X-Band accelerator X-Band 2 IQ Mod 5 RF monitors
S25-Tcav 1 Klystron 4 RF monitors
S24-1, 2, & 3 Feedback 3 Klystrons
S29 and S30 Feedback 2 IQ modulators 476MHz
Total modulators and monitors 23 modulators 40 monitors
Totals at ~2856MHz 15 modulators 33 monitors

23. LLRF Control and Monitor System
1 kW Solid State S-Band Amplifiers – 5 units
Phase and Amplitude Monitors – 16 dual chan units
Phase and Amplitude Controllers – 6 single chan units
Bunch Length Monitor Interface – Need Specifications

24. RF Control Required 11 Units Includes Distribution
RF Control Module consist of the following:
Input Coupler, IQ Modulator, Amplifier, Output Coupler
Filters for I and Q inputs

25. RF Monitor Required 16 Chassis for Injector – Includes Distribution
LO MHz : RF 2856MHz
IF 25.5MHz (8.5MHz x 3 in sync with timing fiducial)
Double-Balanced Mixer
Mixer IF to Amp and then Low Pass Filter
Filter output to ADC sampling at 102MSPS
2830.5MHz Local Osc.
To ADC
LTC2208 SNR = 77dBFS
102MSPS
2856MHz RF Signal

26. 1 kW Solid State S-Band Amplifiers
Electrical Design Complete – Under Review
Mechanical design in progress
Modules in house – in test
Support parts – Some parts in house
Power Supplies, relays, chassis need to be ordered

27. SLAC Linac RF – New Control
The 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

28. Controls Talk

29. Outline LLRF Controls Requirements External Interfaces Schedule Design
Date Needed
Prototype Completion Date
Hardware Order Date
Installation
Test Period
Design
Design Maturity (what reviews have been had)
State of Wiring Information
State of Prototype

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

31. 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

32. LLRF to LCLS global control system
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

33. External Interfaces: Laser - Tcav

34. External Interfaces: L2-L3

35. Date Needed: injector: Dec/06 Prototype Completion Date:
Schedule – for PAD
Date Needed: injector: Dec/06
Prototype Completion Date:
Mar/06: board prototype (2 or 4 chan, thermo)
May/06: final board. Test (incl temp. cycling)
Hardware Order Date: continuous
Hardware Delivery Date:
by Sep/06: chassis (15 dual channel) avail.
Installation: injector: Oct/06
Test Period: injector: Nov/06

36. Date Needed: injector: Dec/06 Prototype Completion Date:
Schedule – for PAC
Date Needed: injector: Dec/06
Prototype Completion Date:
Jan/06: first board prototype
Mar/06: first board prototype if not same as fast PAC
Hardware Order Date: continuous
Hardware Delivery Date:
by Sep/06: chassis (6 single channel)
Installation: injector: Nov/06
Test Period: injector: Nov/06

37. Date Needed: injector: Dec/06 Prototype Completion Date:
Schedule – for slow PAC
Date Needed: injector: Dec/06
Prototype Completion Date:
Mar/06: first board prototype if different than fast PAC
Hardware Order Date: continuous
Hardware Delivery Date:
by Sep/06: chassis (6 single channel)
Installation: injector: Nov/06
Test Period: injector: Nov/06

38. Schedule – for timing/feedback crate
Date Needed: injector: Dec/06
Prototype Completion Date: Fall/06
Hardware Order Date: done
Hardware Delivery Date: have it
Installation: injector: Nov/06
Test Period: injector: Nov/06

39. Design
Design 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:
State 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.

40. PAD – the monitor board

41. PAD – the monitor board

42. PAC – the control board

43. PAC – the control board

44. 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.

45. Overview of LLRF at Sector 20

46. Overview of LLRF at Sector 24