Project: Galil SmartMoves article>NSLS at Brookhaven National Laboratory_V5

Galil Motor Controller Aids Development of Multilayer Laue Lens Designed For Directing Synchrotron Light.

Visible light. Whether it's generated by the sun or an incandescent bulb, it's what helps us see the many colors of the rainbow that paint our everyday surroundings.

Ironically, it's the light that can't be seen by the naked eye that can reveal a whole lot more and even perform amazing feats. Like X-rays that help doctors pinpoint their diagnoses, or infrared light which lets you remotely surf 500 television channels from the comfort of your couch.

You can even let ultraviolet light shower your body at the local tanning salon, or prepare a family meal in minutes with a zap of microwave light.

At the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory located in Upton, NY, synchrotron light is being produced that is so powerful, fast and bright that scientists are able to probe nanostructures as small as a few atoms, revealing details as minute as one-billionth of a meter.

The NSLS produces such light by accelerating electrons inside one of two football field-sized rings at close to the speed of light. When the light is focused on a specific sample-like a human cell or a speck of interplanetary dust-it produces an image of its properties on a detector for analysis.

With a new synchrotron called the NSLS-II currently under construction, researchers can look forward to seeing even more detail with light that is expected to be 10,000 times brighter.

Funded by the U.S. Department of Energy, the facility annually hosts over 2,000 researchers from over 400 institutions to seek insights that are leading to advances in biology, physics, chemistry, medicine, geology, and material science. This includes Alzheimer's disease, HIV/AIDs, breast cancer, osteoarthritis, hard drives, catalytic converters, corrosion, space travel and environmental cleanup.

One such example includes that of Rockefeller University Professor Roderick MacKinnon, M.D., a biophysicist and X-ray crystallographer who won the Nobel Prize in Chemistry in 2003 for work done at the NSLS. His highly detailed portraits showed how a class of proteins generates nerve impulses, which is the electrical activity that is the foundation for all movement, sensation and thought.

In order for Brookhaven's new NSLS-II to produce X-rays 10,000 times brighter than the original NSLS, a specially coated Multilayer Laue Lens (MLL) is used for super precise steering and focusing of the X-ray beams to about 1 nm of the item being analyzed.

Working in concert with CVD Equipment Corporation of Ronkonkoma, NY, and Galil Motion Control of Rocklin, CA, Brookhaven developed a magnetron sputtering system that deposits thousands of ultra-thin layers of two different materials (usually WSi2 and Si) onto silicon substrates to create the MLL. Coating thicknesses range up to 100 micrometers with up to 62,000 layers in a stack, and with the thinnest layer being less than 1 nm.

During production, the substrates are loaded onto a linear-translation stage or "transport car" that rides on a stationary base and rail assembly, and is controlled by Galil's DMC-4020 motion controller.

The standalone, 2-axis controller sends signals to a Trust Linear Amplifier and receives feedback from a high resolution encoder to move the car one-dimensionally back and forth throughout the 23-foot, ultra-high vacuum chamber that contains nine magnetron sputtering guns and four cryogenic pumps. The car travels at well-defined speeds ranging from .01"/second to 9"/second (250 micron/second to 230 mm/second), with maximum acceleration reaching and maintaining no less than 5 inches/second (127 mm/second).

Typically, the coating process can involve the deposition of several thousands of layers over (in some cases) as many as 100,000 non-stop cycles over a period of six days. A critical specification of the MLL deposition system called for achieving a smooth, reliable and repeatable velocity stability with less than .01% ripple. The Galil controller was able to beat the specification by four times.

It did so with its sinusoidal commutation mode which assured that a smooth sinusoidal signal (resolved into a full 16-bits) was sent to the amplifier. This, plus the incorporation of a linear amplifier instead of a switching one, enabled the DMC-4020 to reduce the velocity ripple to 0.0025%.

The engineers at Brookhaven appreciated the position mode of the Galil controller which allowed for easy programming of the back and forth linear motion of the transport car.

Another key feature is that all communication between the DMC-4020 and the host computer is via Ethernet. This enabled the host computer to send commands to the controller to commence a new cycle the moment after receiving signals from the controller announcing the completion of a cycle.

To ensure accuracy and repeatability, the DMC-4020 recorded actual position, position error, velocity and torque every twenty seconds of each cycle to provide data logging and check for system errors.

The new NSLS-II facility houses the magnetron sputtering system in a 4,200 square foot, Class 1,000 clean room which serves as an optics R&D laboratory for development of novel x-ray optics, metrology, and nanopositioning in order to target nanoscale focusing and sub meV energy resolution capability with the synchrotron. The spectral range will go from the far IR in the micro-eV range, to the very hard x-ray region of more than 300 keV.

"Essentially, the NSLS-II is a new, larger and very high brilliance storage ring facility which can be used to generate a broad range of photon energies, but it does so via a single storage ring," said Raymond Conley, NSLS-II Optics Fabrication Group Leader. This is unlike the current NSLS which shoots electrons into one of two round shaped electron storage rings, where they are propelled by magnets to nearly the speed of light, emitting synchrotron light as they go.

When completed in 2015, the single storage ring of the NSLS-II will provide the more intense, focused synchrotron light that will enable researchers to probe minuter, subtler details of their samples. Photons will be delivered with an average spectral brightness that peaks in the 2 keV to 10 keV range, with a spectral flux density exceeding 10^15 ph/s/0.1%BW in all spectral ranges.

This advanced performance is supported by a very stable, high current electron beam (I = 500 mA) with sub-nm-rad horizontal emittance and diffraction-limited vertical emittance at a wavelength of Å.

Whether it's the intricate structure of a hybrid superconductor-semiconductor, or the chemical composition of interplanetary dust particles, proteins, cells or brain tissue, scientists and physicist will be able to count on the NSLS-II at Brookhaven National Laboratory to shed the brightest, finest synchrotron light on their subjects, potentially revealing detail and data formerly unattainable with other x-ray synchrotrons.

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About National Synchrotron Light Source at Brookhaven National Laboratory (http://www.nsls.bnl.gov/)

The National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory in Upton, New York, is a national user research facility funded by the U.S. Department of Energy's Office of Basic Energy Science. The NSLS operates two electron storage rings: an X-Ray ring and a Vacuum Ultraviolet (VUV) ring which provide intense light spanning the electromagnetic spectrum from the infrared through x-rays. Each year over 2300 scientists from universities, industries and government labs perform research at the NSLS. In construction is the new NSLS-II, a medium-energy electron storage ring (3 billion electron-volts) designed to deliver world-leading intensity and brightness, and will produce x-rays more than 10,000 times brighter than the current NSLS. It is expected to be fully operational in 2015.

About Galil Motion Control, Inc. (www.galil.com)

Privately held and profitable for over 100 consecutive quarters, Galil Motion Control, Inc. was founded in 1983 by Jacob Tal and Wayne Baron. Galil became the first company to produce a microprocessor based servo motor controller without tachometer feedback. Since then, Galil has continued to advance motion control technology and has found industry-leading acceptance with over 500,000 controllers successfully installed worldwide. Various applications include machines for the medical, semiconductor,
machine tool, food processing, and textile industries. Recently, Galil has introduced several motion and I/O controllers for the Ethernet including the high-speed Accelera motion controllers and the RIO Pocket PLC series.