A U.S. Department of EnergyOffice of Science LaboratoryOperated by The University of Chicago
Argonne National Laboratory
Office of ScienceU.S. Department of Energy
LCLS Facility Advisory Committee April 29-30, 2004
Undulator Controls OverviewS. Joshua Stein
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Pioneering Science andTechnology
Office of Science U.S. Department
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Undulator Controls : Design Philosophy
• The LCLS Undulator Control System (UCS) will be designed as a stand-along control system with interfaces to the existing SLAC control system.
• Commercial products will be used whenever possible to avoid duplication of effort and maximize the benefits of product maturity.
• When a novel design is required, all attempts will be made to create a “product” which will be useful to all control subsystems of the LCLS.
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Pioneering Science andTechnology
Office of Science U.S. Department
of Energy
Undulator Controls : Resource philosophy
• Whenever possible, APS manpower will be utilized in the design and implementation of the Undulator Control System.
• External consultants will be used to help bridge the gap between SLAC and APS and fill in for engineering manpower that APS is unable to supply.- Bob Dalesio (LANL) is currently working with both APS and
SLAC on LCLS control issues. One of his goals is to ease the communication between the different (independent) control systems. His experience in implementing control systems for multi-laboratory projects make him uniquely qualified in this role.
- Technical design effort will be outsourced as needed from a wide pool of talent in the EPICS community.
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Pioneering Science andTechnology
Office of Science U.S. Department
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Undulator Controls : Schedule and cost
• Whenever possible, real-world experience was used as a basis of estimate for both material and effort costs.
• Using engineering experience from within the APS controls group (who designed and implemented the control system for the APS and LEUTL), initial estimates were gathered from a diverse resource pool.
• Also, consultant effort has been utilized to check and scrub the initial Undulator Control System schedule.
• Many controls requirements are still not defined well enough for accurate vendor-based quotations. However, making practical assumptions allowed for creating estimates that we feel are significantly better than a wild guess.
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Pioneering Science andTechnology
Office of Science U.S. Department
of Energy
Undulator Controls : Interface with SLAC
• While the Undulator Control System will be self-sufficient, there is by necessity a large amount of communication required between the two control systems.- Software
- It is expected that the undulator section will be accessible from anywhere within the LCLS control structure. As such, software interfaces will be designed to accommodate such a requirement, while maintaining the integrity of the individual control systems.
- To leverage the knowledge of the APS controls group staff and minimize unnecessary effort, the EPICS control system platform was chosen for the Undulator Control System. EPICS has a proven track record in the accelerator (and FEL) community.
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Pioneering Science andTechnology
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Undulator Controls : Timing Interface
- Timing- Significant effort will be expended in research and design to
assure that timing information from the injector is available to the Undulator Control System and Undulator diagnostics.
- We envision the design of EPICS compliant timing boards which will reside in both VME and PCI backplanes. These boards will accept the SLC timing messages and output EPICS compatible data for all of the subsystems within the UCS that require timing and time-stamp information.
- The SLC aware IOC design will be utilized extensively in the integration of the Undulator Control System.
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Pioneering Science andTechnology
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Undulator Controls : MPS Interface
- Machine Protection- To protect the undulator components, a machine protection
system (MPS) will be implemented along side the Undulator Control System. This system will be responsible for notifying the LCLS injector of a shutdown condition when a (machine oriented) dangerous situation arises.
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Undulator Controls : “Fine” motion
Beam Code + EPICS Time
EVR
CPU
AI
SMCTL
MotorControls
1.4.2.2.1
WirePosition
Read-backs
Fine Motion Control(strong back
cradle motion)Motors
Wire ScannersAnd Motors
EVR
CPU
SM
ADC
LVDT
1.4.2.2.6
GADC
MotorControls
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Undulator Controls : Strongback Motion
• CAM based platform used for strongback cradle motion- Purpose: Beam Steering and tuning within the intra-undulator
space- Servo motors with integrated brake
- Reduced power (no holding current) reduces heat load in tunnel
- Radiation susceptibility due to integrated electronics - magnitude unknown- Testing at APS to begin during the next run (June 04)
- Position feedback via wire position monitors (installed within the Undulator Alignment scope)
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Pioneering Science andTechnology
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Undulator Controls : Scanning Wire Arm
Scanning Wire Transducer- Using SLAC standard SWA assembly
- Stepper motors with rotary encoders- Purpose: Characterize the beam
• Position• Size• Shape
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Pioneering Science andTechnology
Office of Science U.S. Department
of Energy
Undulator Controls : Macroscopic Motion
Beam Code + EPICS Time
EVR
CPU
SMCTL
MotorControls
MacroscopicMotion Control
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Pioneering Science andTechnology
Office of Science U.S. Department
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Undulator Controls : Macroscopic Motion
• Rough (Macroscopic) Motion- Motion without encoder feedback
- Diagnostic Stage Selection- Translate diagnostic “elevator”
• Stepper motors • Purpose: Select which Diagnostic stage (OTR, SWA,
“No-Diagnostic”) is in use at each station- Camera controls
- Adjust Focus and aperture for both OTR and inspection cameras• Stepper motors• Purpose: “Tune” video picture
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Pioneering Science andTechnology
Office of Science U.S. Department
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Undulator Controls : Signal Analysis
EVR
BPM
CPU
BPM
BPM
BPM
BPM
BPM
BPM
EVR
CPU
GADC
1.4.2.3.21.4.2.3.1
BPMPickups
Charge Monitors(Toroid)
EVR
CPU
GADC
1.4.2.3.2
Scanning WiresADCs
3 IOCs
Downconverters
33 BPMs33 IOCs
2 Charge monitors2 IOCs
Beam Code + EPICS Time
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Pioneering Science andTechnology
Office of Science U.S. Department
of Energy
Undulator Controls : Signal Analysis
• RF BPM [33 in total - one per break section]- Physics design to be done by SLAC
- Detectors (RFBPM)- Front-end electronics (amplification)
- Interface with Timing triggers- Physics requirements will determine ADC resolution and
conversion rate - expected to be 12-14 bits at 40MHz - VME backplane
- High data rates may necessitate individual processors for each BPM.
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Pioneering Science andTechnology
Office of Science U.S. Department
of Energy
Undulator Controls : Signal Analysis
• Charge Monitor [1]- Controls hardware to be designed by SLAC
- Toroid and ICT pair- COTS VME based ADC- Interface with Timing triggers
• Scanning Wire [33]- Hardware to be designed by SLAC
- Mechanical Assembly including motors- COTS VME based ADC- Interface with Timing triggers
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Office of Science U.S. Department
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Undulator Controls : Video
11 OTRs
Ethernet
EVR
CPU
BI
BO
DAC
Lamps&
Actuator
CamerasElectronics
1.4.2.4.1
OTRMonitors
7 stations
Ethernet
EVR
CPU
BI
BO
DAC
Lamps&
Actuator
CamerasElectronics
1.4.2.4.3
ObservationVideo
Beam Code + EPICS Time
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Office of Science U.S. Department
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Undulator Controls : Video
• OTR Stages [11]- Acquire and analyze beam
- Position- Shape- Size
- 30 Hz capture and analysis rate (possibly up to 120Hz in the future)
- Large FOV requirement at “reasonable” resolution- Allows digital “zoom”- No need for two camera configuration- Digital interface for frame grabber
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Pioneering Science andTechnology
Office of Science U.S. Department
of Energy
Undulator Controls : Temperature monitoring
• Two thermal sensors per each strongback- Used for low data-rate trend analysis and alarms
CPU
AI
1.4.2.5
AI
AI
AI
StrongbackTemperature
66 temperatures
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Pioneering Science andTechnology
Office of Science U.S. Department
of Energy
Undulator Controls : Vacuum control
GPIB
CPU
2gauges
BI
BO
AI
AO
AI
GP307 IGHP937 CCG
38 ionPumps
PowerSupplies
1 exitvalve
SLAC PMVC
1.4.2.6.1
2 RGAs
PPS
CPU
Gauge
RGA
1.4.2.6.4
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Pioneering Science andTechnology
Office of Science U.S. Department
of Energy
Undulator Controls : Vacuum control
• Pump controller interface to control system- Whenever possible, commercial pump controllers will be
purchased with standard communications protocols (Serial, Ethernet, etc.).
• Vacuum gauges- Whenever possible, commercial gauges will be purchased with
standard communications protocols (Serial, Ethernet, etc.).
• RGA- Typically, these devices use embedded PCs as both a user
interface and data acquisition unit. Integrating these into the UCS will most likely be done via Ethernet based function calls.
• Vacuum Valve- Position monitoring only via binary inputs from limit switches.
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Pioneering Science andTechnology
Office of Science U.S. Department
of Energy
Undulator Controls : Software
• Control software will be run on the EPICS ‘platform’- Defines a low level control schema and implies higher-level
software.
• Whenever possible, existing software will be utilized- Software maturity is an important part of creating a stable
control system.
• Re-use / borrow high level apps from other facilities whenever possible
• High level tools will be installed or written to allow flexible ‘science’ software and support the LCLS community as much as possible without compromising the UCS.- Correlated and consistent operator screens- Data archiving- External software hooks
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Pioneering Science andTechnology
Office of Science U.S. Department
of Energy
Undulator Controls : Machine Protection System (MPS)
• Scope needs to be fully defined before details extracted
• Must interface with Injector to inhibit beam trigger
• Local (inter-undulator) machine protection may include:- Cherenkov detectors- Motion limit detectors- Vacuum
- Pressure- Gas detection- Valve position
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Pioneering Science andTechnology
Office of Science U.S. Department
of Energy
Undulator Controls : Design documentation
• It is important to create and maintain system documentation from the beginning of the design process to avoid the “as built” syndrome.
• In particular, all installed hardware and software will be logged and tracked via ‘live’ tools such as the APS developed IRMIS suite.- Maintain an integrated, comprehensive and searchable
database of:- Installed hardware- Control software- Cable- And all interconnections…
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Pioneering Science andTechnology
Office of Science U.S. Department
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Undulator Controls : Conclusions
• Immediate goals- Begin prototyping a video capture system for the OTR
diagnostic- Camera choice- Capture options- Software model
- Strongback cradle Motion tests- Servo motor radiation susceptibility- Software modeling of five axis motion control
- Documentation of controls requirements for ‘high-risk’ tasks- OTR Video- Strongback Motion- BPM Acquisition and analysis