Issue Date: September 14, 2015
U.K. Seeks To Enhance Its Synchrotron
Sitting among green fields in the Harwell Science & Innovation Campus just outside the university town of Oxford, England, is the U.K.’s only synchrotron. At 561.1 meters in circumference, it accelerates electrons near the speed of light to generate intense beams of X-rays and infrared and ultraviolet light that can reveal molecular structure and dynamics. Run as a nonprofit organization, the synchrotron, named Diamond Light Source, is 86% owned and funded by the U.K. government and 24% owned by the Wellcome Trust, a large charitable foundation.
Diamond opened in 2007 at a cost of about $500 million. Initially, it had seven light beamlines coming off the electron storage ring. These are directed to experimenting stations, each of which is set up for a specific type of analysis, whether it be measuring molecular movements in proteins or evaluating the structure of novel materials under various pressures. In 2007, there were fewer than 30 synchrotron light sources in the world. But there are now about 40, including synchrotron light sources with potential for a greater range of applications.
Now, to ensure it can compete as a world-class research facility, Diamond is in a race to add more beamlines and analytical capability.
Since 2007, Diamond has increased its capacity to 25 beamlines at a cost of about $190 million. It is adding another eight beamlines over the next three years at an additional cost of about $170 million.
Diamond is at the forefront of analysis for chemistry, biology, and physics, supporting research that includes work on catalysis, drug development, and metal-organic frameworks (MOFs). It plays a major role in U.K. science, with more than 3,000 researchers—mostly from the U.K.—now using it. Their work at the synchrotron on average generates 500 peer-reviewed papers annually.
“It’s all about extending capability,” says Guenther Rehm, head of beam diagnostics as he surveys a plethora of experimenting stations from a walkway inside the huge toroid—or ring-shaped—structure. Although the large space appears to be full with its 25 beamlines, in theory, Diamond has capacity for up to 40. “We can also upgrade old beamlines,” Rehm says.
In the area housing the storage ring, where electrons are accelerated to high speeds, Rehm explains that pairs of magnets are used to change the direction of the electron beam. This change of direction causes the fast-moving electrons to emit a bright light, which can then be directed into the experimenting stations.
The magnets can be upgraded when required so that narrower, more stable beams, which are considered to be more suitable for some experiments, can be generated, Rehm says.”
Diamond has a 3-giga-electron-volt beam. Bigger synchrotrons tend to have brighter X-ray beams, which researchers can use to look deeper into certain materials such as metals. The biggest ones, with 6-, 7-, and 8-GeV beams, are located in Grenoble, France; Argonne, Ill.; and Hyōgo prefecture, in Japan, respectively.
According to the scientists running Diamond, however, 3 GeV is sufficient to undertake plenty of analyses. One field where they feel Diamond is playing a key role is catalysis. “We are developing the imaging capabilities with a focus on catalytic systems” because catalysis is one of the most important industrial fields in the world, says Stephen Price, a catalyst researcher with Diamond.
The synchrotron has become more relevant to scientists researching in the field of catalysis because the U.K. Catalysis Hub, which features additional lab facilities and expertise, has been colocated in Harwell near Diamond. Catalyst firms that use the synchrotron include BASF and Johnson Matthey.
Using one of the synchrotron’s beams, researchers recently generated a combination of microfocus X-ray fluorescence and X-ray diffraction computed tomography images to identify, for the first time, molecular-level catalyst site activity in the liquid phase while a reaction was taking place (Angew. Chem. Int. Ed. 2015, DOI: 10.1002/anie.201504227). They evaluated NanoSelect, BASF’s platinum and molybdenum catalyst for selective hydrogenations used in fine chemicals production.
In addition to the X-ray imaging set to benefit BASF, scientists working at Diamond have an array of analytical systems available, including a magnetism beamline and three macromolecular crystallography beamlines.
In a world first, Diamond in recent months introduced a new beamline from which synchrotron experiments can be run for months and even years. With capability to undertake diffraction of powders, the beamline could be useful for scrutinizing changes in the properties and behavior of materials such as those used in cements and batteries, says Claire Murray, the scientist who manages the beamline.
Diamond plans by year-end to introduce a new type of macromolecular crystallography beamline solely dedicated to data collection directly from crystals grown in experimental plates at the beamline or the lab. The new beamline will be highly automated, and users will be able to access it remotely.
X-ray crystallography already is a key application for Diamond where the beamline intensity at the synchrotron allows scientists to determine structures from sample crystals that might show no measurable diffraction in their home lab. In-house scientists Dave Allan and Mark Warren say they can save researchers hours, if not days, compared with analysis techniques done in a typical lab. In minutes, researchers using the beamline can determine the structure of the smallest samples of a crystallized substance through single-crystal X-ray diffraction.
Along the beamline that Allan and Warren use, a diffractometer in a second experimentation station can be used to determine how crystal structures change under different environments such as high pressure. There is a big push for applying this instrument in the field of MOFs, Allan says. “You can see how the framework adapts as you change pressure,” he says.
Warren recently developed a gas cell that could be used to test samples of materials, such as MOFs, at pressures up to 1.5 kilobars.
As well as minor developments such as the one Warren made, fundamental improvements to the beamlines are also anticipated as part of a 10-year plan currently being drafted, says Andy Dent, physical science coordinator for Diamond. In preparation for the plan, the scientists who run Diamond are exploring how they might improve the electron source, detectors, optics, and its ability to handle and analyze increasing quantities of data, in line with advances at other synchrotrons around the world, Andrew Harrison, chief executive of Diamond, says in a recent report.
Although newer and more powerful synchrotrons potentially have a broader range of applications than Diamond, the team of scientists working in the U.K. facility are keen to prove that they have what it takes to keep their machine at the forefront of science. “It’s not just about being the biggest or the brightest,” Dent says. “There’s more to it than brute force.”
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