SESAME opens doors to international collaboration

In a synchrotron, charged subatomic particles (typically electrons) are accelerated through a large ring. As their paths bend, the electrons emit synchrotron light, which can range from infrared wavelengths up to X-rays. “Beam lines” attached to the ring carry off this light to perform a wide range of scientific experiments. In 1997, as German synchrotron BESSY I was nearing replacement, physicist Herman Winick of the Stanford Linear Accelerator Center in Menlo Park, Calif., proposed using it as the seed for an international research facility in the Middle East. Called SESAME, the facility is now under construction in Jordan, a collaboration of nine Middle East nations. Science News editor in chief Tom Siegfried recently spoke with Winick about SESAME’s history and importance.

How did the SESAME idea originate?

“Nothing approaches the impact of X-rays as a tool for understanding materials.” Tom Siegfried

At a committee meeting in September of 1997, as the new machine [BESSY II] was coming close to getting online, I asked the question, what are you going to do with the old machine?… The answer came back, we’re going to call in a junkyard dealer, cut it up into small pieces and get rid of it.… I said immediately that it’s a shame to destroy such a beautiful, productive machine.… And I said why not offer it as a gift to serve as the centerpiece for a new facility in the Middle East?… One of the other people on the committee was Gus Voss, a very prominent German accelerator physicist.… At a meeting in Torino [Italy] in November of 1997 he made a presentation about moving this machine to the Middle East. This suggestion was received extremely enthusiastically, particularly by Middle East scientists. … It was brought to the attention of UNESCO … and it began to be developed under the UNESCO umbrella.

At first the plan was just to upgrade BESSY I from 800 million electronvolts (MeV) to 1 billion electronvolts (GeV), but now SESAME will be an even bigger machine. Why?

We realized that merely upgrading BESSY I but keeping its basic structure was not going to be adequate.… So we said let’s abandon that whole thing and go to 2 GeV with a totally new machine, and in fact it was reviewed by the European Union, which said that 2 GeV was still too low. So the present planning design has been made for what we call a third-generation 2.5 GeV light source. However, all the German equipment from BESSY I is now sitting in Jordan, and we will use the injector. An 800 MeV injector can also inject into a 2.5 GeV ring…. It’s not as good as injecting at the full energy, but it’s a cheaper way to get started.

What’s the price tag for the whole project?

That’s a tricky question to answer because the land and the site are gifts from Jordan, with the building and its improvements…. So if you add the whole thing up, and really put in realistic numbers for the site, the building, the infrastructure, the injector, the beam lines and everything, it’s approaching $100 million of value.… The main cost for SESAME is really $20 million to buy the components of a new storage ring, of which we have about $5 million. And a big question now is where and when is that $15 additional million going to come from.

The motivation for SESAME is as a facility for doing science and also for working together across countries and cultures as an example of how science can foster that kind of cooperation, right?

Precisely. UNESCO called it a model project for other regions…. It has brought together people. These nine countries include Turkey and Greek Cyprus, which sit at the same table. They don’t recognize each other. It includes Israel, the Palestinian authority, Iran and Pakistan.

What is it about synchrotron radiation facilities that makes them ideal for this purpose?

Because they affect such a broad area of science…. Nothing approaches the impact of X-rays as a tool for understanding materials — biological materials, semiconductor materials, catalytic chemical materials, environmental toxins, whatever.… Bang for the buck, the attractiveness and the impact over so many areas of science and technology could not be matched by anything else.

Who coined the name SESAME?

I take credit for that…. I decided that it needed to be named SESAME, because I claim there’s three important connotations of the word SESAME: One, it’s a door opener — it opens the door to jewels, to scientific knowledge; another is the spice, sesame, a Middle East spice, the sesame seed, it’s the seed for growth…. But most important it’s

Sesame Street

… because that is where young people are taught to cooperate and respect each other. So everyone said that’s great but what’s it mean, and I figured out what it could mean: Synchrotron light for Experimental Science and Applications in the Middle East.

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