The CLS brings the brightness and quality of a synchrotron x-ray beam to a scale that can be used in a local experimenter’s laboratory or, eventually, in a hospital or clinic. Ronald Ruth, Ph.D.

Miniature Synchrotron Sheds New Light on Research

Radiologists are among those who could take advantage of a new device capable of producing high-intensity, tunable and near-monochromatic x-ray beams while being small enough to be used in a typical university lab.

The Compact Light Source (CLS), a miniature synchrotron, has been developed by Lyncean Technologies in Palo Alto, Calif.

“The CLS brings the brightness and quality of a synchrotron x-ray beam to a scale that can be used in a local experimenter’s laboratory or, eventually, in a hospital or clinic,” says Lyncean President Ronald Ruth, Ph.D.

Etta Pisano, M.D., professor of radiology and biomedical engineering and vice-dean of Academic Affairs at the University of North Carolina School of Medicine, has used synchrotrons in her research and can envision using the new CLS. “It provides x-rays of single energy which potentially may be useful for human imaging,” she said. “We may be able to develop new ways to use x-rays with this device.”  

Laser Undulator is the Key

Synchrotrons—large rings of magnets that store electron beams—have been used for three decades to generate x-rays. Because these x-rays come from a very tiny and very high energy source, they are directed in a beam.

“In a large synchrotron, that beam looks like a searchlight spinning around,” explained Dr. Ruth. “And as it spins past you, you see a pulse of x-rays.”

Synchrotrons produce x-rays by accelerating electrons sideways—basically wiggling them back and forth, or bending them in a circle. Techniques have been developed to enhance the technology and make it more useful to scientists, including material scientists, condensed matter physicists, biologists and radiologists. Stadium-sized synchrotrons now use “undulator” magnets, which provide the best beam lines.

“A miniature synchrotron seems impossible when you first think about it,” Dr. Ruth said. “One of the requirements to get x-rays with one angstrom wavelength, or an energy of about 12 kilovolts, is that the electron beams have to be very high energy—many billions of electron volts. That’s what causes these devices to be very large in size.”

But the undulation that wiggles the electron beam back and forth does not have to be done with magnets. It can also be done with a light beam. And that’s what Lyncean has developed: a laser undulator. Because it uses laser wavelengths, the energy of the electron beam can be small, consequently decreasing the device size.

“This big ring of magnets shrinks down to tabletop size,” said Dr. Ruth. “The CLS storage ring is about two meters long by a meter wide.”

Scientific Applications

Lyncean announced in 2004 that it was constructing the CLS and the prototype is now up and running. The first beta CLS is already in production and will be installed at the Scripps Research Institute in La Jolla, Calif., where it will be part of the new Accelerated Technology Center for Gene to 3D Structure (ATCG3D). The ATCG3D is one of the specialized centers of the Protein Structure Initiative funded through the National Institute of General Medical Sciences (NIGMS) and the National Center for Research Resources (NCRR). Part of the National Institutes of Health, NIGMS and NCRR support basic biomedical research and foster development of new technologies.

“Essentially within one laboratory we will produce a protein, crystallize the protein and do synchrotron x-ray diffraction experiments,” said Peter Kuhn, Ph.D., professor of cell biology at Scripps. “This is something that, outside of a national lab, is completely unprecedented.”

The CLS allows an individual scientist to drive an entire experiment, which just wasn’t possible before, Dr. Kuhn said. “Having a small-scale, high-performance synchrotron is essentially one of the last critical steps in the process,” he said.

Dr. Pisano’s work with synchrotrons has involved diffraction enhanced imaging (DEI), which uses a crystal downstream of the object being radiated to capture the diffraction part of the x-ray beam.

“When an object is exposed to an x-ray beam, the images created with traditional radiography are due to the absorption component of the beam—in other words, which photons get through,” Dr. Pisano explained. “But we’ve been doing some experiments at the synchrotron facility at Brookhaven National Laboratory that use the diffraction component of the beam, meaning the photons that get bounced off. We’re capturing them with a crystal and making images with it.”

With a focus on breast cancer imaging, Dr. Pisano has been researching whether diffracted beams can be used to determine the extent of disease in a specimen. “It’s very preliminary at this point—we haven’t done it on any humans,” she said. “But we’ve seen that DEI images seem to show finer detail at the edges than typical absorption images of the same specimens. We found that fine lines around the surface of the cancer were more visible. Those are often important to see, because you can tell that something is spreading out into the surrounding tissue, as opposed to just confined to a local space.”

CLS development has been supported by NIGMS through a Small Business Innovation Research (SBIR) grant. NIGMS Director Jeremy M. Berg, Ph.D., said that with its decreased size and cost, the CLS “puts an option on the table that hasn’t existed.”

Dr. Ruth said he sees the CLS as practical enough to one day be used in a hospital, where radiologists will be among those to reap the benefits. “There has been a tremendous amount of research, but many radiologists have not been interested in x-ray research with synchrotron light because they didn’t see the possibility that it could ever be practical,” he said. “But now the possibility is not only there, we’re actually building devices.

“I believe the Compact Light Source will substantially expand the interest in using synchrotron light for radiography,” he said.


A rendering of the Compact Light Source miniature synchrotron, which can produce high-intensity, tunable and near-monochromatic x-ray beams while remaining small enough for a university lab.

Image courtesy of Lyncean Technologies.

To read more about the Compact Light Source being developed by Lyncean Technologies, go to www.lynceantech.com/sci_tech.html.