PE
Researchers have developed a new source of intense terahertz (THz) radiation which could offer a less harmful alternative to x-rays, and have industrial applications.
THz radiation is at the infrared end of the spectrum, between mid-infrared and microwaves, and has a frequency between 0.1 and 10THz. Unlike visible light, THz radiation can penetrate through materials such as plastic, cardboard, wood and composites.
The THz band coincides with the vibrational and rotational spectral fingerprints of large molecules, which makes THz spectroscopy a powerful tool for identifying hazardous substances such as drugs and explosives. It could also be used for analysing biological molecules such as DNA, and uncovering the intricacies of semiconductors.
Scientists from the University of Strathclyde and Capital Normal University in Beijing have found a new way to create THz radiation, by producing high-charge bunches of relativistic electrons in a laser wakefield accelerator.
The team showed that when an intense ultra-short laser pulse is focussed into helium gas, a plasma bubble moving at the nearly the speed of light is formed. These high-charge beams of electrons are distinct from the usual low-charge (picocoloumb), high-energy (100s MeV to GeV), femtosecond duration electron bunches that are commonly observed from the LWFA.
“This is an unprecedented efficiency at these THz energies,” said Professor Dino Jaroszynski, of the Strathclyde’s Department of Physics, who led the research. “The increasing availability of intense THz sources will lead to completely new avenues in science and technology.”
Please enable JavaScript to view the comments powered by Disqus.
Read now
Download our Professional Engineering app
A weekly round-up of the most popular and topical stories featured on our website, so you won't miss anything
Subscribe to Professional Engineering newsletter
Opt into your industry sector newsletter
Javascript Disabled
Please enable Javascript on your browser to view our news.