Beams to order from table-top accelerators

August 26, 2011 | 3:50 pm

Berkeley Lab published the following story on August 22, 2011. For more about table-top accelerators, read Crashing the Size Barrier in symmetry magazine.

A laser pulse through a capillary filled with hydrogen plasma creates a wake that can accelerate an electron beam to a billion electron volts in just 3.3 centimeters. The same LOASIS accelerating structure has been modified to tune stable, high-quality beams from 100 to 400 million electron volts. (Photos by Roy Kaltschmidt, Berkeley Lab Public Affairs)

Laser plasma accelerators offer the potential to create powerful electron beams within a fraction of the space required by conventional accelerators – and at a fraction of the cost. Their promise for the future includes not only compact high-energy colliders for fundamental physics but diminutive sources of intensely bright beams of light, spanning the spectrum from microwaves to gamma rays – a new kind of ultrafast light source for investigating new materials, biological structures, and green chemistry. Compared to today’s giant science facilities, “table-top” laser plasma accelerators may eventually be able to do equally powerful research with minimal environmental impact.

To reach these goals, laser plasma accelerators must be able to produce high-quality, stable electron beams and tune those beams to the users’ needs. The LOASIS program at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) has already demonstrated high-quality beams up to a billion electron volts in a mere 3.3 centimeters; the BELLA project will reach 10 billion electron volts in a single meter.

Now the LOASIS team has demonstrated a simple way to tune highly stable beams through a wide range of energies. They describe their methods in the journalNature Physics.

Surfing the wave

“To describe how a laser plasma accelerator works, I use the analogy of a surfer riding a wave,” says Wim Leemans, who heads the LOASIS program in Berkeley Lab’s Accelerator and Fusion Research Division. “The surfers are the electrons themselves. The waves form when a laser pulse plows through a plasma.”

In a plasma, atomic nuclei (ions) are separated from electrons, and immensely strong electric fields can build up between the oppositely charged particles when they are separated by the waves behind a powerful laser pulse. Some of the electrons in the plasma are swept up by the waves and are quickly accelerated to high energy.

“In this case the wave is a tsunami, and it doesn’t much matter what the surfers do; they’ll be carried along,” Leemans says. “That’s called self-trapping. But there are other ways a surfer can catch a wave. Real surfers can gauge the size and speed of an oncoming wave and start paddling to match its momentum.”

Attempts to create tunable electron beams through momentum-matching have been tried, by injecting electrons into the accelerating field – first giving them a boost using colliding laser pulses to catch the wave, then using a different drive-laser pulse to excite a wave on which those surfing electrons can be accelerated to high energies. It’s an approach that demands sophisticated timing and synchronization, and along with other tuning methods for one-stage accelerators, requires electron injection that’s localized in space and time.

“But there’s a third way of helping a surfer catch a wave,” Leemans says, “and that’s by slowing the wave until even slow surfers can catch it – then increasing the speed of the wave.” In other words, a two-stage process – and this turns out to be the secret to tunable, high-quality electron beams.

For their experiments the Berkeley Lab scientists modified the same 3.3-centimeter LOASIS accelerator and the same 40-trillion-watt peak-power drive laser, dubbed TREX, they used to produce the first billion-electron-volt beam. The accelerator is a block of titanium sapphire with a narrow capillary through it, filled with hydrogen gas that’s ionized to a plasma by a jolt of electricity, just before the drive-laser pulse enters.

“Two-stage” acceleration

Slowing the laser wake and then speeding it up requires controlling the wake’s phase velocity. To modify the LOASIS system for “two-stage,” tunable acceleration, the researchers introduced a supersonic jet of helium gas that passes through the accelerator’s hydrogen-filled capillary at the upstream front end. This sharply increases the density of electrons in the subsequent plasma. The plasma density then falls off rapidly downstream.

A laser plasma accelerator uses a laser pulse (red and blue disks, extreme right) to create a wake through a plasma, creating strong electric fields. Like surfers on a wave, free electrons ride the wake and are accelerated to high energies. Only the electron bunch propelled by the first wave (white glow) is shown in this simulation. (Simulation by Jean-Luc Vay and Cameron Geddes)

“The extra density itself serves as a lens to focus the laser to higher intensity, and the laser is focused right where the extra density is beginning to decrease,” says Leemans. Here at the edge of the “density downramp,” the slower waves trap electrons more readily. “The waves in the wake are falling farther behind the laser pulse as it enters the region of lower density.”

Density control is only one way to control wave velocity, however. Another method is through laser intensity – an unexpected gift from Albert Einstein’s Special Theory of Relativity. Leemans explains, “The particles in the plasma waves have slowed because of the increased density, but they’re still moving relativistically, near the speed of light,”

Carl Schroeder, a theoretician with LOASIS and an author of the Nature Physics paper, says that “as the laser is focused, its intensity increases, driving larger and larger plasma waves.  Larger waves increase the relativistic mass effect. This reduces the frequency of the wave and stretches the wavelength. The peaks of the waves fall even farther behind the laser pulse.”

Says experimenter Tony Gonsalves, first author of the Nature Physics paper, “If we simply end the plasma there, we have a stable low-energy accelerator. But with a second stage we can accelerate the electron beam to much higher energy, and we can tune that energy.”

The same drive-laser pulse whose wake has been slowed by plasma density and laser intensity now powers into the low-density region of the accelerator; the following waves, carrying their extra load of electron “surfers,” rapidly catch up.

“Tuning the energy is possible because by changing the density or location of the higher-density plasma, we can change its focusing power, the intensity of the laser pulse, and how much the pulse spreads out in the following lower-density plasma,” Gonsalves says. “This allows us to tune the acceleration length and the final beam energy. The stability we achieve over our tunable range is quite amazing.”

By tailoring plasma density in the two zones over the length of the accelerator, the LOASIS researchers were able to tune the energy of the electron beams over a range from 100 million electron volts to 400 million electron volts, while maintaining energy stability to within a few percent.

Leemans says, “Tailoring plasma density longitudinally this way is a concept that shows a new path to the level of sophisticated tuning for accelerators and light sources that users of conventional facilities just take for granted. It’s a major step toward perfecting the laser plasma light sources and accelerators of the future.”

- Paul Preuss

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Particle accelerators help develop new cancer fighting drug

August 26, 2011 | 1:45 pm

Light sources are the ultimate app for particle physics. Researchers around the world use the powerful X-ray beams that light sources create for materials science, protein structure analysis, historical research, pharmaceutical research and drug development and the list keeps going. Argonne National Laboratory published the following story on August 25, 2011 about contributions that the Advanced Photon Source made to developing a new drug to treat skin cancer. For more examples about the applications of particle physics, visit Accelerators for America’s Future. 

Powerful x-ray technology developed at the U.S. Department of Energy Office of Science’s (DOE-SC’s) national laboratories, including the Advanced Photon Source at Argonne National Laboratory, has enabled the discovery of a groundbreaking new drug treatment for malignant melanoma, the deadliest form of skin cancer. The drug, Zelboraf (vemurafenib), received Food and Drug Administration (FDA) approval on Wednesday, August 17, 2011. In revealing the structures of diseased and disease-causing molecules at their basic level, the DOE-SC’s extremely bright x-ray light sources enable scientists to develop potential new treatments.

The protein crystallographic structure of the new anti-cancer drug, vemurafenib, is the green honeycomb structure at middle left. Four dotted red lines show where it attaches to a target area in the mutated enzyme, disabling it from promoting the growth of tumors. Image courtesy of Plexxikon Inc.

“This technology is a wonderful example of how innovations at our national laboratories lead to discoveries in a wide variety of fields,” said Energy Secretary Steven Chu. “In this case, we are pleased to have been involved in research that has shown great promise in the battle against life-threatening melanoma.”

An increasing number of drug discovery companies and medical researchers are turning to the powerful x-ray facilities at the DOE national laboratories to probe the causes of disease and develop new treatments by revealing new insights into a wide range of diseases. Researchers from Plexxikon Inc., the drug discovery company that developed the melanoma treatment, used x-ray light sources at Argonne and two other DOE national laboratories—SLAC National Accelerator Laboratory and Lawrence Berkeley National Laboratory—to determine the specific, three-dimensional protein structure of a mutated enzyme that tells melanoma cancer cells to multiply uncontrollably. The research at the APS was carried out at the Structural Biology Center Collaborative Access Team x-ray beamline 19-BM.

The researchers used the technique called macromolecular x-ray crystallography to determine the protein structure in order to develop a drug that would prevent the enzyme from multiplying. The newly FDA-approved drug, Zelboraf (vemurafenib), was extremely successful during clinical trials in disrupting the disease and extending the lives of those diagnosed with it.

“Plexxikon’s drug discovery approach is critically dependent on harnessing the power of x-ray crystallography, and the role of DOE facilities in enabling the development of compounds like vemurafenib has been fundamental,” said Gideon Bollag, Senior Vice President for Research at Plexxikon. “With the insight we gain from the three-dimensional structures, we have an atomic road map to rationally optimize our drug candidates.”

In addition to this treatment for melanoma, the x-ray light sources at the DOE-SC labs have revealed new insights into diseases such as Alzheimer’s disease, swine flu, autoimmune disorders, bird flu, hepatitis, and the common cold.

The original DOE press release can be read here.

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Fermilab scientist receives $2.5 million award for innovative accelerator work

August 16, 2011 | 10:19 am

Fermilab issued the following press release on August 16, 2011.

Alex Romanenko, sitting on the edge of a large cryogenic vessel, holds one of the superconducting RF cavities made of niobium. Photo: Fermilab

Alex Romanenko, a materials scientist at Fermi National Accelerator Laboratory, will receive $2.5 million from the Department of Energy’s Office of Science to expand his innovative research to develop superconducting accelerator components. These components could be applied in fields such as medicine, energy and discovery science.

Romanenko was named a recipient of a DOE Early Career Research Program award for his research on the properties of superconducting radio frequency cavities made of niobium metal. The prestigious award, which is given annually to the most promising researchers in the early stages of their careers, includes a $2.5 million award over five years to continue work in the specified area.

“Dr. Romanenko and his proposed research show great promise,” said Tim Hallman, associate director of the DOE’s Office of Science for Nuclear Physics. “We are pleased that he has been selected to receive an Early Career Research Program award to continue this work.”

Romanenko’s work could explain why some superconducting radio frequency cavities are highly efficient at accelerating charged particles to high speeds while others are not, as well as prescribe new ways to make cavities even more powerful. His research links the performance of SRF cavities to the quality of the niobium metal used to make them. In particular, he investigates specific defects and impurities in niobium. Although scientists take painstaking measures to ensure that the niobium is completely pure and that the final SRF cavities are free from any contaminants, dust or debris, the cavities do not always perform the way that they should. Romanenko’s research is dedicated to finding out why that happens.

Romanenko began his research on SRF cavities as a graduate student at Cornell University, an institution known for its SRF research. He continued his award-winning work at Fermilab when he joined the laboratory in 2009 as a Peoples Fellow, a prestigious position given to scientists who have the potential to be leaders in their field.

Through his research, Romanenko found that a new, previously unexplored, type of defect near the cavity surface may result in surface differences that are responsible for a cavity’s inferior performance. What he found was surprising: the defect sites often contained niobium-hydrogen compounds, which might form when the cavities are prepared for operation. Specifically, he was able to pinpoint the problematic area to the first 40 nanometers of a cavity’s surface, a thickness equivalent to 120 layers of niobium atoms.

“The technology of these cavities has developed so fast recently that it is ahead of the corresponding science,” Romanenko explained. “We know how to make them work to a certain level of performance, but do not necessarily understand the full physics behind why they do so. I hope to understand why cavities behave in certain ways first, improve on this and then apply what I learn to other materials.”

Strung together like the pearls of a necklace and cooled to ultralow temperatures, SRF cavities can accelerate particles with high efficiency. Photo: Fermilab

If Romanenko can isolate the specific nanostructural effects that cause problems in cavities, then Lance Cooley, Romanenko’s supervisor and head of the new Superconducting Materials Department in Fermilab’s Technical Division, is prepared to direct other scientists to develop ways to prevent or control them and transfer that knowledge to industry. This could someday make it possible to mass-produce nearly perfect niobium cavities as well as lay the groundwork for cavities made from other superconducting materials that can perform at higher temperatures and accelerating fields. Such high-performance cavities—strung together to create powerful, intense particle beams—would lead to accelerators that can be used in industry, in hospitals and at research institutions. These accelerators are needed, for example, to produce a range of radioisotopes for medical diagnostics and have the potential to treat nuclear waste, among other applications.

“This award recognizes the high caliber of research that takes place at Fermilab,” Cooley said. “It is because of the laboratory’s existing world-class research program that Alex’s research is likely to succeed.”

The monetary award will cover part of Romanenko’s research efforts, fund a postdoctoral associate and a part-time technician, and pay for advanced analysis techniques used to examine surfaces in the next five years.

Fermilab is a national laboratory supported by the Office of Science of the U.S. Department of Energy, operated under contract by Fermi Research Alliance, LLC.

The DOE Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit the DOE Office of Science website.

Rhianna Wisniewski

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Synchrotron studies shed light on Alzheimer’s disease

July 18, 2011 | 1:07 pm

Top: A series of images from research at the National Synchrotron Light Source. 1) Amyloid plaques associated with Alzheimer’s disease in human brain tissue, fluorescing in green; 2) zinc and 3) copper ions in the same tissue sample; and 4) an overlay of the previous three images reveals that the plaques contain high levels of the two metals. Bottom, from left: Lisa Miller, Andreana Leskovjan, and Tony Lanzirotti at one of the NSLS beamlines at Brookhaven National Lab where they conducted their Alzheimer’s research. Images and photo courtesy of L. Miller, Brookhaven National Laboratory

A synchrotron light source helped provide one more piece of the puzzle that may help doctors diagnose Alzheimer’s disease early on, before it does permanent neurological damage.

A research team led by Lisa Miller, a biophysical chemist at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory and Stony Brook University, reports high levels of iron are associated with the formation of amyloid plaques, the misfolded protein clumps responsible for the deterioration of neurons in Alzheimer’s victims.

A protein is a string of amino acids folded into a three-dimensional shape that gives it its function. In patients with Alzheimer’s disease, Abeta proteins improperly fold, causing them to have a high affinity for each other. The resulting protein clumps, known as amyloid plaques, are associated with the progression of Alzheimer’s and have been found to contain high levels of metals.

Miller’s team performed X-ray fluorescence microscopy (XFM) experiments to study brain tissue samples in a mouse model of Alzheimer’s disease. XFM uses synchrotron X-rays to light up metals in brain tissue samples.

“We’re trying to understand the role of normal metal ions— iron, copper, zinc— in the formation of Alzheimer’s disease and its progression and pathology,” Miller said.

Previous studies have found elevated levels of metal ions are associated with the plaques in the brain tissue of patients with late-stage Alzheimer’s disease, but it remains unclear when and why this metal accumulation occurs.

Researchers in Miller’s lab studied mice that had been genetically engineered to overexpress Abeta – the protein that aggregates to form amyloid plaques. They used XFM, at both NSLS at Brookhaven National Laboratory and the Advanced Photon Source at Argonne National Laboratory, to image the Ca, Fe, Cu, and Zn in the mouse brains and looked at how the levels of each metal changed over time.

They found that late-stage mouse plaques accumulated zinc in the hippocampus, the region of the brain responsible for long-term memory storage. They also noticed a correlation between elevated iron levels in the cortex, the region responsible for higher brain functions such as thought and reasoning, and the onset of plaque formation, although iron was not found within the plaques themselves (see Figure).

The latter observation provides extremely valuable information to doctors, who may be able to look at patients’ brain iron levels using MRI to get clues about the early onset of Alzheimer’s disease, Miller said.

On a molecular scale, Miller is interested in shedding light on the complex mechanism underlying Alzheimer’s disease. Her lab’s involvement in Alzheimer’s research started eight years ago when they analyzed samples of human brain tissue from patients who had died of Alzheimer’s disease and found amyloid plaques loaded with metals.

Since that time, Miller has been designing experiments to figure out how amyloid plaques exert their toxic effects and what role metal ions play. Her lab uses XFM for these experiments since it is a unique technique for simultaneously imaging and quantifying the levels of iron, copper and zinc at microscopic resolution in biological samples.

When it comes to imaging with XFM, brighter photon sources can achieve higher spatial resolution. The researchers used NSLS to achieve a spatial resolution on the order of tens of microns for imaging the mouse and human plaques. For more precise imaging of the cortex and hippocampus, they looked to APS, a newer and brighter synchrotron, to image large areas with a spatial resolution down to a few microns.

Not only will these experiments pave the way for early diagnosis, they could help lay the groundwork for the development of therapeutic interventions.

Currently, there is no cure for Alzheimer’s disease and diagnosis depends on a series of cognitive tests performed long after the onset of the disease process.

“Symptoms for Alzheimer’s disease don’t start until well after amyloid plaques have formed and many brain cells have died,” Miller said. However, it appears as though iron levels become elevated long before symptoms develop, making Fe a potentially important biomarker for early Alzheimer’s disease diagnosis and intervention before the disease progresses.

-       Christine Herman

For more information, read the paper in NeuroImage.

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SLAC X-rays help discover new drug against melanoma

July 12, 2011 | 12:22 pm

SLAC first published this story on July 12, 2011. For more information about light sources and their many applications, check out the latest issue of symmetry magazine.

The new drug, vemurafenib, is the green honeycomb structure on the left. Four dotted red lines show where it attaches to a target area in the enzyme, disabling it. Studies at SLAC's Stanford Synchrotron Radiation Lightsource helped scientists at Plexxikon, a Berkeley-based drug development company, decipher these important structures. Image courtesy Plexxicon, Inc.

It was front page news around the world: a drug designed to disrupt malignant melanoma, the deadliest form of skin cancer, was so successful in its latest round of testing in humans that the tests were halted – like an early-round knockout in boxing – so patients in the trial who were receiving other treatments could be moved to the new medicine.

A crucial part of the research for developing this new drug, called vemurafenib, took place at three DOE national laboratories: SLAC National Accelerator Laboratory, Argonne National Laboratory and Lawrence Berkeley National Laboratory. A Berkeley-based drug-discovery company, Plexxikon, used the labs’ powerful X-ray facilities to determine the precise structure of a mutated protein involved in this cancer – and potential drug candidates that could stop its spread.

Plexxikon’s success, reported last month, is an impressive victory for an emerging approach to combating illness: creating drugs custom-designed to throw molecular monkey wrenches into the disease process.

First researchers identify a target protein that plays a key role in the disease. In this case, it was an enzyme involved in cell growth that sometimes mutates and makes cells multiply out of control, the hallmark of cancer. If the scientists could find a small molecule that fit perfectly into a specific place in the mutated enzyme, they could block the enzyme’s action and slow or stop the cancer.

The researchers screen hundreds of small molecules – potential drugs – and identify the most promising ones. Then they bind each molecule to the target protein, crystallize the bound pair and study it with powerful beams of X-rays, which scatter off the atoms in the crystal and reveal its 3-D structure. This technique, known as macromolecular X-ray crystallography, has become an important tool for probing large, complex biological molecules and discovering new drugs. Molecules that look like good blockers are chemically tweaked to optimize their performance, and their structures determined again to see if they bind to the target protein more effectively. It may take several rounds of such chemical tinkering and X-ray structure work to find the optimal molecule for stopping the disease with no significant side effects. Drug candidates then undergo a rigorous series of highly-regulated trials to determine their effectiveness, safety, side effects and proper dosages.

While malignant melanoma accounts for less than 5 percent of all skin cancers, it is the most aggressive and deadly, killing nearly 9,000 Americans this year, according to the American Cancer Society. Image courtesy Plexxikon Inc.

Plexxikon also used the X-ray crystallography facilities at SLAC’s Stanford Synchrotron Radiation Lightsource, or SSRL, to design two other drugs that are now being tested in humans. One is aimed at type II diabetes and other metabolic disorders. The other attacks cells found in many metastatic breast, colorectal, lung, and prostate cancers, and may also be effective against autoimmune diseases such as rheumatoid arthritis, multiple sclerosis and lupus.

“Our unique success story in producing a life-changing drug in a matter of a few years is a testament to the power of structural information,” said Chao Zhang, the company’s head of structural chemistry. He said structures produced by X-ray crystallography “provide precise information on how a drug interacts with its protein target. This information points us in the most productive directions, enabling a small chemistry team to generate new drug candidates quickly.”

Macromolecular crystallography is a rapidly growing activity. Six of SSRL’s 30 beamlines host a large number of such projects each year; the specialized beam lines are funded primarily by the Department of Energy’s Office of Biological and Environmental Research and the National Institutes of Health. Worldwide, scientists are using more than 130 X-ray synchrotron beamlines to study biological molecules. X-ray crystallography was used to determine some 87 percent of the nearly 74,000 structures submitted to date to the Protein Data Bank, the worldwide repository for 3-D structure information on large biological molecules, and the vast majority of those used synchrotron X-rays.

Since scientists first demonstrated the feasibility of using synchrotron radiation for macromolecular crystallography at SSRL in 1976, greater X-ray intensity, better beam quality and improved detectors, computers and sample-handling automation have dramatically increased the speed and accuracy with which scientists can obtain their results.

“Ten years ago we could typically examine only 20 crystals per 8-hour shift on a beamline, and collect data from one or two of them,” said Ana Gonzalez, SSRL senior staff scientist. Now, she said, users can manipulate their samples and measure the data remotely, over the Internet, “and during a single shift we can look at some 100 crystals and also collect datasets from 20 to 30 of them.”

The future offers potentially transformative new technologies thanks to SLAC’s Linac Coherent Light Source, or LCLS. In experiments there, an international team of scientists showed that they can get the rough 3-D structures of proteins from tiny protein nanocrystals, which may be much easier to create than the larger crystals needed for traditional synchrotron-based X-ray diffraction. The nanocrystals are suspended in water and squirted through the powerful LCLS X-ray laser beam, which pulses 120 times a second. In the instant before the intense X-rays destroy a nanocrystal, detectors record a flash of X-ray diffraction information. Finally, scientists use sophisticated computer programs to merge the data from hundreds of thousands of nanocrystals to reveal the protein’s structure.

By enabling scientists to determine the structures of many proteins that don’t fully crystallize, “the ultrafast LCLS X-ray beam has the potential to guide the design of next-generation drugs,” said Plexxikon’s Zhang.

- Mike Ross

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Particle accelerator reveals what the first birds looked like

July 1, 2011 | 3:26 pm

SLAC Today published this story on July 1, 2011. To learn more about this scientific discovery, tune in to watch “Jurassic C.S.I.: In Living Color” on the National Geographic Channel on Thursday, July 7 at 10 p.m. ET

Research at SLAC's Stanford Synchrotron Radiation Lightsource allowed scientists to examine two fossilized birds. Confuciusornis sanctus, shown in the artist's concept above, is a species from 120 million years ago that had the first known bird-like beak.

Scientists report today that they have taken a big step in determining what the first birds looked like more than 100 million years ago, when their relatives, the dinosaurs, still ruled the Earth. At the Department of Energy’s SLAC National Accelerator Laboratory, they discovered chemical traces of a pigment, an important component of color, that once formed patterns in the feathers of the fossilized birds.

The pigment, eumelanin, is one of the coloring agents responsible for brown eyes and dark hair in many modern species, including humans. It would have been one of the factors that determined the birds’ color patterns, along with structural properties of the birds’ feathers and other pigments they ingested as part of their diets.

The discovery, reported June 30 in Science Express, will help give textbook illustrators, diorama makers and Hollywood special-effects artists a more realistic palette for their depictions of ancient animals. Understanding these pigment patterns is important for science, too, since they play a role in a wide range of behaviors that are important in evolution such as camouflage, communication and selecting mates.

“This is a pigment that evolved a very, very long time ago but is still actively synthesized by organisms on the planet, and we found a way to map it and show its presence over 120 million years of geological time passing,” said geochemist Roy Wogelius of the University of Manchester, one of the leaders of an international team that reported the discovery. “It is a direct relationship between you, me, and some extremely old organisms.”

Said report co-author Uwe Bergmann of SLAC, “If we could eventually give colors to long extinct species, that in itself would be fantastic. Synchrotron radiation has revolutionized science in many fields, most notably in molecular biology. It is very exciting to see that it is now starting to have an impact in paleontology, in a way that may have important implications in many other disciplines.”

Working at SLAC’s Stanford Synchrotron Radiation Lightsource, the researchers examined two fossilized birds. Confuciusornis sanctus, which lived 120 million years ago, was one of many evolutionary links between dinosaurs and birds, sporting the first known bird-like beak. Gansus yumenensis, considered the oldest modern bird, lived more than 100 million years ago and looked a bit like a modern grebe.

Scientists had previously found melanosomes—the biological “paint pots” where melanin pigments are made and stored—in both ancient and living organisms. They used information about the structures of the melanosomes to make an educated guess about the colors of the pigments inside. But the newly published research shows that this prior approach has limitations. The team looked instead for chemical traces of the pigments themselves with two sophisticated X-ray techniques developed at SSRL.

The first technique identifies specific chemicals or elements in a sample, and it can examine whole fossils rather than the tiny fragments used in previous methods, revealing pigment patterns across the whole specimen. With it, the researchers unveiled traces of specific elements in and around the tissues, bones and surrounding rock of Confuciusornis sanctus. These traces provide an image of the pigmentation patterns from this long-dead bird in eerie detail.

The most striking of these trace elements was copper. As Bergmann points out, copper, which can be toxic in high levels, has persisted in the fossil in significant amounts, appearing in the images as a ghostly glow in places where feathers remained. What was it doing there? Before they could answer that, the researchers had to determine what chemical form the copper took.

SSRL staff scientist Sam Webb used the second X-ray imaging technique to study the fossil of a single feather from Gansus yumenensis. His analysis revealed that the copper in the fossil took the same form as copper trapped by eumelanin pigment. What’s more, Webb said, “When we looked outside the feather we didn’t see the copper at all.”

Couple that chemistry with the way the copper was distributed, and the research team was faced with a mind-boggling conclusion: They had seen actual color patterns in the fossil bird feathers. “There is a stunningly remarkable preservation of pigments,” Wogelius said. The team found the same relationship between copper and pigments in samples from modern feathers and squid.

“These new techniques for teasing out evidence of pigmentation will take a lot of the guesswork out of reconstructing the appearance of extinct dinosaurs and birds,” said renowned dinosaur illustrator James Gurney, author of the best-selling Dinotopia series.

The discovery opens a window on the biochemistry of ancient creatures, and could lead to a far greater understanding of what they ate and the chemistry of their surroundings.

”The fossils we excavate have vast potential to unlock many secrets about the original organism’s life, death and subsequent events impacting its preservation,” said paper co-author Phil Manning, a paleontologist at the University of Manchester. “In doing this, we unlock much more than just paleontological information. We now have a chemical roadmap to track similar pigments in all life.”

Press Release

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Fermilab’s Project X could offer potential energy applications

April 12, 2011 | 11:13 am

This story first appeared in Fermilab Today on April 12.

According to the Nuclear Energy Institute, U.S. nuclear power plants have produced roughly 70,000 tons of radioactive waste over the last four decades. By 2025, scientists expect the amount of waste to be roughly 100,000 tons. The nuclear industry faces an ever-increasing waste problem, and Fermilab’s proposed Project X is developing the technologies that may contribute to a solution.

View this animation to see how Fermilab's Project X would be integrated into the laboratory's accelerator complex.

Last week at AccApp’11, an accelerator applications conference hosted by the American Nuclear Society and the International Atomic Energy Agency, Fermilab’s David Johnson explained how Project X could demonstrate the technologies required for accelerator-driven nuclear waste treatments.

“Fermilab has proposed the construction of a high-power proton linac for support of our high-energy physics program, and we are exploring the possibility to expand the application of the project to nuclear physics and energy applications,” Johnson said.

Project X is a proposed high-intensity proton accelerator complex that would support experiments in neutrino and rare processes physics. By using highly efficient superconducting radio frequency cavities, the technology of choice for next-generation accelerators, Project X would create a continuous-wave beam of protons. While the Project X mission is focused on particle physics, the beam that will be produced has uses that go beyond particle physics. The continuous-wave beam—as opposed to a pulsed one—makes it possible for Project X to also support experiments validating assumptions that underlie accelerator-driven waste treatment concepts. It would also demonstrate the associated accelerator and target technologies, Johnson said.

By hitting a lead-bismuth target with protons, a high-power, continuous-wave linac would create fast, or highly energetic neutrons. These fast neutrons would burn up the dangerous radioactive elements in nuclear waste, significantly reducing its half-life. In order to meet the requirements for treating nuclear waste on the industrial scale, the accelerator must operate reliably with virtually no downtime. Johnson explained that by advancing technologies and producing stable accelerator operations, Project X could serve as a proof of concept for the application.

“We would like to get the nuclear community excited about this potential facility,” Johnson said. “We welcome any and all participation.”

Elizabeth Clements

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Next-generation particle accelerator starts up at Daresbury Laboratory

April 6, 2011 | 5:57 am

Today more than 30,000 particle accelerators are at work in hospitals, factories, shipping ports and laboratories around the world. Historically, breakthroughs in accelerator science come from basic science, leading to applications for diagnosing and treating disease, cleaning up polluted air and water and greener industrial processes. Next-generation technology like the EMMA accelerator will help pave the path for even more applications. STFC issued this press release about EMMA on April 1:

A brand new technology that promises a range of applications from treating cancer to powering safer nuclear reactors has reached another world first in its development. This milestone was confirmed yesterday, 31 March 2011, at the Science and Technology Facilities Council’s (STFC) Daresbury Laboratory in Cheshire. Scientists from across the world are celebrating the successful start up of the pioneering EMMA accelerator which is set to impact fundamental science and change the way such particle accelerators across the world are designed and built in the future.

EMMA is a proof of principle prototype for a brand new type of particle accelerator, designed by an international team of scientists, including a number of the UK’s top universities and institutes. A major part of the BASROC CONFORM project, EMMA is funded by the Research Councils UK (RCUK) Basic Technology programme. A supporting statement and quotes from the CONFORM project and its members is available at https://www.conform.ac.uk/news/EMMAacceleration.pdf.

Particle accelerators already have a wide range of uses in many areas of science, but their potential is limited by their size, complexity and cost. EMMA will provide the technology to overcome these issues and take these applications to a new level. A compact 20 million electron volt prototype, EMMA not only uses technology that is simpler and less expensive than equivalent accelerators in existence, it also promises applications from treating cancer to powering safer nuclear reactors that produce less hazardous waste.

EMMA has now achieved its most significant milestone yet. For the first time, an electron beam was steered around the circumference of EMMA’s ring and then successfully accelerated to 18 MeV. This momentous milestone, and a world first, not only confirms that the design of the most technically demanding aspects of EMMA is sound, it also demonstrates the feasibility of EMMA’s technology, which now paves the way for the construction of a whole new generation of more powerful, yet more compact and economical accelerators.

The University of Huddersfield’s Professor Roger Barlow, leader of the CONFORM project said: “This is an outstanding milestone for EMMA, as well as for everyone involved in the CONFORM project, and is one that will define the way forward for this kind of particle accelerator across the world. The achievement is a direct consequence not only of the enlightened funding of the Basic Technology programme, but also of the investment that STFC has made in establishing the two Institutes for Accelerator Research – Cockcroft and John Adams.”

EMMA’s concept is based on a ring of magnets which use their combined magnetic field simultaneously to steer and focus the electron beam around the machine. The strength of the magnetic field increases as the beam spirals outwards while it is accelerated around the ring. Due to the strength of the magnetic focussing, the displacement of the beam as it accelerates and spirals around the ring is much smaller than in any equivalent accelerator. As a result, EMMA’s ring of magnets is much more compact and the beam is better controlled. EMMA’s next steps will be to move towards full acceleration from 10 to 20 MeV and commence the detailed characterisation of the EMMA accelerator and its novel acceleration scheme.

EMMA is the result of a truly multidisciplinary team from several world leading establishments which make up the CONFORM project. These include the Universities of Manchester, Oxford, Surrey, Imperial, Brunel and Huddersfield, the Cockcroft and John Adams Institutes, STFC and a number of international partners and UK industry. It was then design engineered and constructed by STFC’s scientists at its Daresbury Laboratory.

Susan Smith, Director of ASTeC at STFC’s Daresbury Laboratory said: “This is a great achievement, and is testament to the skill and dedication of the engineering and technical staff at Daresbury Laboratory, as well as to all the national and international partners and collaborators. This milestone marks the beginning of a detailed experimental programme that will provide all the information required for the design and construction of all future accelerators of this type.”

Carol Johnstone, of the Fermi National Accelerator Laboratory in the USA, and one of the international team, said: “I have just announced the success of EMMA at Fermilab. I am so impressed and proud to collaborate with the UK team.”

View the press release

Elizabeth Clements

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