Brookhaven’s Light Show

Lilach Tamam, a researcher from Bar-Ilan University, Brookhaven Lab’s Ben Ocko, and Bar-Ilan Professor Moshe Deutsch in the National Synchrotron Light Source lab. Courtesy of Brookhaven Lab

Lilach Tamam, a researcher from Bar-Ilan University, Brookhaven Lab’s Ben Ocko, and Bar-Ilan Professor Moshe Deutsch in the National Synchrotron Light Source lab. Courtesy of Brookhaven Lab

by Stewart Ain
Staff Writer

Bar-Ilan University physics professor Moshe Deutsch has been coming to Long Island’s North Shore in Suffolk County three or four times a year since 1992. His destination: the Brookhaven National Laboratory in Upton. He has been working with Ben Ocko, a physicist at the lab.

“Typically he brings one or two students for a two-week period,” Ocko said.

What does the lab offer he can’t find in Israel? The National Synchrotron Light Source, an accelerator that makes electrons travel at nearly the speed of light. Through the use of magnets, the electrons are forced to race in circles around the synchrotron.

“As they bend, they give off X-rays,” Ocko explained during a recent tour of the synchrotron. “But instead of radiation coming out in all directions, it comes out as a fairly focused beam of X-rays that can be further focused with X-ray optics.”

This beam of X-rays is one billion times brighter than conventional X-ray sources, he noted.
Chi-Chang Kao, chairman of the lab’s National Synchrotron Light Source Department, said such beams are useful for “basic research in biology, environmental medicine, industrial research and archeology.”
The Dead Sea Scrolls, for instance, were examined with a synchrotron “to see what area and what time period they came from and the source of the material,” Ocko said.

He said that in examining material, “the brighter the beam the better because it allows us to see with finer detail.”
For instance, a single hair follicle is between 10 and 50 microns and the synchrotron at Brookhaven has the ability to “see” its structure with a resolution of 1 micron. But there are newer synchrotrons that can “see” with a resolution of one manometer or 1,000 times better, Ocko said.

The Brookhaven synchrotron has between 30 to 35 stations around its ring where scientists work simultaneously on their different projects. The length of time they are permitted to work at those stations is allocated based upon “scientific excellence,” Deutsch observed.

“Three or four times a year you submit a proposal and there is a peer review by committees that determine who gets beam times and who does not,” he said by phone from Israel. “If your proposal is approved, you can get to use the beam for that project three or four times a year for two years.”

The synchrotron runs 24 hours a day, seven days a week except for planned maintenance breaks. That means that the scientists who are chosen to work at the synchrotron — the machine is open to all free of charge — must work there continuously during their allocated time.

“We usually come as a group of three or four people and work 12-hour shifts, two at a time,” Deutsch said. “You have to analyze the results and compare them with theory. It is not initially obvious at the beam line what you got, and it takes anywhere from two months to 10 years for project results to reach the publication stage. Usually it’s half a year.”
Deutsch said his work is focused on the molecular-level structure of the surface of liquids. One of the more notable findings concerned surface freezing.

“Surface freezing is unusual because in most situations the bulk of a material freezes before the surface,” he said. “Think of a group of people who are closely packed together. The crowd is compressed but those on the edge are able to more freely move around and disconnect from the crowd. The same thing with matter — molecules on the surface will break the bonds that bind them when they are solid (and thus become liquid) easier when heated than those in the bulk.

“But when we tried to see what happens on the surface of wax, we found that just the opposite happened — the surface froze [when the temperature dropped] and we had to go three or four more degrees for the bulk to freeze. Nobody knows why.

“But it has many implications. We were working with a scientist from Exxon, and he said fuel contains some wax and that this may influence diesel injection engines — in cold climates the wax may clog the injector holes. So you have to change the amount of the wax inside the fuel. This gives us insight into something that is happening that is counterintuitive.”

Deutsch added that surface freezing has recently been found to influence the activity of some biological molecules and to play a role in processes occurring in plants.

“It will take more time until we fully understand this effect and its role in many natural processes,” he added.

Signup for our weekly email newsletter here.

Check out the Jewish Week's Facebook page and become a fan! And follow the Jewish Week on Twitter: start here.

Westchester Jewish Conference

Westchester’s Jewish Community Relations Organization