lcls facility advisory committee april 29-30, 2004

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

2

Pioneering Science andTechnology

Office of Science U.S. Department

of Energy

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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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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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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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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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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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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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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Undulator Controls : Macroscopic Motion


EVR

CPU

SMCTL

MotorControls

MacroscopicMotion Control

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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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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


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• 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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• 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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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


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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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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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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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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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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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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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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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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

lcls facility advisory committee april 29-30, 2004

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