An experiment conducted with Jefferson Lab's Free-Electron Laser has shown how to make a highly useful form of light -- called terahertz radiation -- 20,000 times brighter than ever before. Jefferson Lab is a Department of Energy laboratory located in Newport News, Virginia.

The name "terahertz radiation" derives from the frequency of the radiation -- of the order of one trillion oscillations per second. The corresponding wavelength is of the order of tenths of a millimeter. Terahertz radiation is thus located in the spectrum of electromagnetic radiation between the upper end of the microwave range (mm wavelength) and the far infrared (hundredths of mm).

Terahertz radiation is non-ionizing and shares with microwaves the capability to penetrate a wide variety of non-conducting materials.

Gwyn Williams, JLab's Free-Electron Laser Basic Research Program manager, conceived and led the multi-laboratory team conducting the experiment, which took place during November 2001. The results were published in the Nov. 14, 2002, issue of the international science journal Nature.

Among the prospective benefits, the breakthrough lights the way toward better detection of concealed weapons, hidden explosives and land mines; improved medical imaging and more productive study of cell dynamics and genes; real-time "fingerprinting" of chemical and biological terror materials in envelopes, packages or air; better characterization of semiconductors; and widening the frequency bands available for wireless communication.

To produce for the first time ever, intense terahertz radiation, researchers from JLab and two other Department of Energy laboratories -- Brookhaven National Lab and Lawrence Berkeley National Lab -- made use of the fact that the driver linac of JLab's Free-Electron Laser is made up of intense electron bunches that
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Contact: Linda Ware
ware@jlab.org
757-269-7689
DOE/Thomas Jefferson National Accelerator Facility
27-Jan-2003