Issued May 18, 1998





UPTON, NY - A new "chemical camera" that can catch a glimpse of chemical reactions lasting only a few trillionths of a second was unveiled today in a ribbon-cutting ceremony at the U.S. Department of Energy's Brookhaven National Laboratory.

Called LEAF, for Laser-Electron Accelerator Facility, the apparatus will give chemists from BNL and collaborating institutions a unique view of the reactions that govern processes in the human body, the environment and industry. It is the first of its kind in the world.

"Just as we all use cameras to capture the events of our lives, chemists will use this facility as a camera to capture the reactions that make our lives possible," said BNL Director John Marburger. "It will let them add more snapshots to the album of human knowledge."

The $2 million facility, funded by DOE's Office of Basic Energy Sciences, is the first such accelerator in the world to be dedicated to chemistry.

It is based on an innovative design that uses a titanium-sapphire laser to boil bursts of electrons off a thin cathode. These are then boosted to faster speeds by an accelerator designed by scientists at BNL's Accelerator Test Facility and made by Northrop Grumman Corporation.

LEAF can produce pulses of electrons that have up to 9 million electron volts of energy but last only five picoseconds, or trillionths of a second. The laser and electron gun are precisely synchronized to an accuracy of just one picosecond.

Such pulses will allow scientists to follow extremely fast chemical reactions by using the laser flash to "freeze frame" the reaction in progress. A sequence of frames can be assembled to construct a "movie" of the reaction. The high intensity of the beam will also make it possible to study reactions involving supercritical liquid water and carbon dioxide that may one day be used as nonpolluting alternatives to chemical solvents.

LEAF currently features two experimental stations, where scientists can mount their samples to be investigated, but the design is expandable to allow for two more stations.

Brookhaven National Laboratory creates and operates major facilities available to university, industrial and government personnel for basic and applied research in the physical, biomedical and environmental sciences, and in selected energy technologies. The Laboratory is operated by Brookhaven Science Associates, a not-for-profit research management company, under contract with the U.S. Department of Energy.

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