World's fastest movie camera to study atomic nuclei

Posted by Ken Kola

If The Hobbit's 48 frames per second seems like a lot, how does a million trillion sound?

A team from the UK's Science and Technology Facilities Council (STFC) is working on a technique to create an X-ray camera with the shortest pulses ever made.

The idea is to study atomic nuclei to improve understanding of how medicines interact within the body, as well as of catalytic processes in new materials for energy storage.

The team is expecting to be able to generate X-ray laser pulses shorter than one attosecond - a millionth of a millionth of a millionth of a second. Right now, the best that 's ever been achieved is 67 attoseconds.

"Such pulses will be important for observing and influencing processes within molecules, atoms and nuclei which occur at progressively smaller sizes and faster time scales," says accelerator scientist David Dunning.

"Such short timescales are difficult to conceive. To put them into context, stretching out one attosecond to one second is the equivalent to stretching out one second to 30 billion years - or more than twice the age of the universe."

The aim is to actually film with atomic resolution - and the team says  it would only require a modest addition to an existing X-ray Free-Electron Laser (FEL), such as the LCLS in the USA or SACLA in Japan. More likely, though, the technique will be tested first on a dedicated FEL test facility, such as the proposed CLARA project at Daresbury Laboratory.

By using magnets to manipulate electrons from a particle accelerator, FELs generate intense light of exceptional quality. They work across a much broader range of wavelengths than conventional lasers. Currently, FEL pulses flash on and off quickly enough to 'freeze-frame' the motion of electrons within atoms or molecules.
 
But the new technique should help scientists probe deeper, and observe the much faster dynamics of electrons interacting with the nucleus - even the dynamics of the nucleus itself.