THE hills 30km north-west of Amman, Jordan’s capital, are home to a miracle of scientific diplomacy called Sesame. Proposals to build this device, the world’s most politically fraught particle accelerator, date back nearly 20 years. The delay is understandable. Israel, Iran and the Palestinian Authority, three of the project’s nine members, are better known for conflict than collaboration. Turkey does not recognise the Republic of Cyprus, but both have worked together on the accelerator. As well as Jordan, the other members are Bahrain, Egypt and Pakistan. Nonetheless, Sesame, a type of machine called an electron synchrotron, is about to open for business. The first electrons are expected to complete their initial laps around its 133 metre circumference ring this month.
Electron synchrotrons are smaller cousins of proton synchrotrons such as the Large Hadron Collider (LHC), near Geneva. Instead of probing the frontiers of physics, they probe the structure of materials. Corralled by giant magnets, the electrons travelling around them emit radiation ranging in frequency from the infrared to X-rays. This can be used to look at anything from metals to biological tissues. Synchrotron radiation is more intense than other available sources, letting researchers collect data faster and from smaller samples. It can also penetrate matter more deeply, and resolve smaller features.
There are around 60 electron synchrotrons in the world, but none before Sesame has been in the Middle East. They are expensive beasts, but Sesame is cheaper than most. The Diamond Light Source, in Britain, which opened nearly a decade ago, cost £260m ($330m) to build. The cost of building Sesame has been just $79m. This is, in part, because of Jordan’s low labour costs. It is also a consequence of Sesame’s less ambitious specifications. But the resourcefulness of Sesame’s architects has played an important part as well.
The project has a long history. More than 25 years ago Abdus Salam, a Nobel-prizewinning physicist, called for a synchrotron to be built in the Middle East. In 1997 two other physicists, Herman Winick and Gustav-Adolf Voss, suggested moving one intact from Berlin. BESSY I, the machine they had in mind, was to be decommissioned and replaced. It would thus become redundant and available for dispatch elsewhere. In 2002 the Winick-Voss idea was scrapped in favour of building a more powerful Middle Eastern facility from scratch. Yet BESSY I lives on in Sesame. It serves as a booster, giving the electrons an initial kick before they are accelerated to their full energy in the main ring. That, reckons Sir Christopher Llewellyn Smith, Sesame’s president, saved the project about $4m. America, Britain, France, Italy and Switzerland have also donated components from decommissioned synchrotrons.
Cheap though Sesame may be, scraping the necessary money together in a region enmeshed in conflict has been no mean feat. All nine project members agreed to make annual contributions of different levels. Banks refused to handle those from Iran, for fear of American sanctions. Nonetheless, $48m of the total has come from the project’s members. The European Union has provided more than $10m, some of which has been used by CERN, the organisation that runs the LHC, to design and oversee the construction of Sesame’s corralling magnets. And, in an effort to rein in running costs, the project’s bosses hope to build a solar-power plant to supply the synchrotron’s electricity. That would make it the first accelerator to be powered solely by renewable energy.
Researchers with expertise in synchrotron engineering have pitched in. Sir Christopher, who was CERN’s director-general between 1994 and 1998, knows a thing or two about particle accelerators. And next year one of his successors at CERN, Rolf-Dieter Heuer (D-G from 2009 to 2015), will also succeed him as Sesame’s president.
Sesame’s electrons will have energies of 2.5bn electronvolts, the units usually used to describe such things. That is a lot. Applying Einstein’s famous equation, e=mc2, where e is energy, m is mass and c is the speed of light, it means that an electron circulating around Sesame’s ring will weigh 5,000 times more than one which is at rest. The radiation they generate is tapped at various points , to create “beam lines” for things like X-ray crystallography. Sesame will open with two beam lines. One will pipe infrared light to a microscope, and the other will pass X-rays through both organic and inorganic samples. Two more beam lines are planned for the next three years, at a cost of $15m. Sesame can, in theory, host more than 20 of them. One use to which they may be put is the analysis of antiquities. Synchrotron radiation has, for example, been employed to read scrolls too delicate to unfurl.
But beam lines are not Sesame’s only draw. The project has involved a huge amount of work from groups within the region. It also acts as neutral ground, on which the Middle East’s scientists can meet. As Roy Beck of Tel Aviv University, who sits on the Sesame users’ committee, puts it, “We all talk the same language. We all talk science.”
Researchers prize the radiation produced by synchrotrons so highly that they will cross the world to clinch some precious time on one. For scientists travelling to such facilities from the Middle East, though, snarl-ups with visas have in the past made such trips difficult or impossible. Now that they have a synchrotron on their doorstep, the inconveniences of Western immigration controls may affect these researchers somewhat less.