Computer Science and Instrumentation Research

Opportunities at CLS

Johannes M. VogtCanadian Light Source

University of Saskatchewan2001-10-20

CLS Control System

• More than 100 computers

• Mix of technologies (including industrial control hardware and scientific data acquisition hardware)

• Software based on a system called EPICS that was originally developed for Star Wars. Today EPICS is used to control accelerator facilities and radio telescopes.

CLS Control System (cont.)

• The computer hardware is interconnected over a mix of Ethernet and Profibus.

• The control system measures and controls several thousand signals, e.g.,– Position of the beam in the storage ring to within 1 m– Magnet set points and feedback values– Temperature sensors, valves, flow switches ...

• All of this data is acquired and logged in real-time.

Grad student opportunities exist in data networking, data-base system design, data acquisition software, software for data analysis and display.

Transition Radiation Monitors

• Non-destructive method of obtaining beam profile information

• A thin aluminized Mylar foil is moved into the beam• Transition radiation is produced as the beam passes

through the foil• We are working on capturing a video image of the

beam, determining the position and shape of the beam and then readjusting steering elements in the accelerator.Grad student opportunities exist in image processing, feedback algorithms, statistical analysis of video images and pattern recognition.

Transition Radiation Monitors (cont.)

Transition Radiation Monitors (cont.)

Orbit Correction System

• The beam orbit in the storage ring must be maintained within 1m and the orbit corrected at approx. 100 Hz.

• The position of the beam is monitored to within 1m at 56 monitor stations within the storage ring.

• Orbit corrector magnets are used to correct the beam position.

Grad student research opportunities exist in control theory and implementation of the control algorithm.

Vibration Monitor

Position of the experiment stable to 1m?• Internal Vibration Sources

– Pumps, compressors, fans ...– Ramping of the booster– Crane, forklift, people walking ...

• External Vibration Sources– Trucks, trains, planes– Wind on building walls– Ocean surf ?

Separate concrete slabs for building, booster, storage ring/ beamlines. How well do the isolation joints in the floor isolate the slabs?

Vibration Monitor (cont.)

• A portable vibration monitoring system was developed to measure building vibration and displacement.

• Custom software to acquire the data and analyse the data is under development.

• Building vibration studies were done in collaboration with the College of Engineering.

Grad student opportunities exist in building vibration research.

Vibration Monitor (cont.)

Accelerometer

SCXI-1531PXI-6052EPXI-1010

Mainframe

Accelerometer

SCXI-1531PXI-6052EPXI-1010

Mainframe

PXI-PCI 8335 MXI-3 with fiber cable, up to 200 m long

Computer

SCXI-1349

SCXI-1349

Vibration Monitor (cont.)Acceleration [μm/s ]

0 6 Time [s]

0

-8

8

2

Time [s]

Displacement [μm]

0

2

-2

Acceleration Spectrum [μm/s ]2

0

10

0 100 200 300Frequency [Hz]

42

0 642

Electronics

Policy:• Buy if possible, develop only specialized circuits

that are not available off-the-shelf• Design, develop, prototype, build small quantities,

then contract out or transfer technology

CLS has developed:• High speed digital electronics (500 MHz, ECL)• A fibre-optic system for the distribution of trigger

pulses (3-jitter less than 50 ps)• A high voltage circuit that switches 1.8 kV in about

250 ps, triggered by a fibre-optic signal

Electronics (cont.)

Need a fast Beam Position Monitor for turn-by-turn readout.

Two systems are available commercially:• One of them does not work (for us)• One of them may satisfy requirements, but

is prohibitively expensive

Grad student R&D opportunity exists for the development of fast Beam Position Monitor electronics.

Summary

Possible Research Areas:

• Control System – Control theory, implementation of control/ feedback algorithms

• Data Processing – Data networking, data-base system design, data acquisition software, software for data analysis and display, image processing, pattern recognition.

• Building Vibration Studies – Measure, analyze

• Electronics – Fast Beam Position Monitor for turn-by-turn readout