The extremely intense X-ray flash knocks so many electrons out of the iodine atom (right) such that it pulls in the electrons of the methyl group (left) like an elecetromagnetic version of a black hole, before finally spitting them out.
When scientists at the Department of Energy’s SLAC National Accelerator Laboratory focused the full intensity of the world’s most powerful X-ray laser on a small molecule, they got a surprise: A single laser pulse stripped all but a few electrons out of the molecule’s biggest atom from the inside out, leaving a void that started pulling in electrons from the rest of the molecule, like a black hole gobbling a spiraling disk of matter.
Within 30 femtoseconds – millionths of a billionth of a second – the molecule lost more than 50 electrons, far more than scientists anticipated based on earlier experiments using less intense beams, or isolated atoms. Then it blew up.
The results, published today in Nature, give scientists fundamental insights they need to better plan and interpret experiments using the most intense and energetic X-ray pulses from SLAC’s Linac Coherent Light Source (LCLS) X-ray free-electron laser. Experiments that require these ultrahigh intensities include attempts to image individual biological objects, such as viruses and bacteria, at high resolution. They are also used to study the behavior of matter under extreme conditions, and to better understand charge dynamics in complex molecules for advanced technological applications.
“For any type of experiment you do that focuses intense X-rays on a sample, you want to understand how it reacts to the X-rays,” said Daniel Rolles of Kansas State University. “This paper shows that we can understand and model the radiation damage in small molecules, so now we can predict what damage we will get in other systems.”
Like Focusing the Sun Onto a Thumbnail
The experiment, led by Rolles and Artem Rudenko of Kansas State, took place at LCLS’s Coherent X-ray Imaging instrument. CXI delivers X-rays with the highest possible energies achievable at LCLS, known as hard X-rays, and records data from samples in the instant before the laser pulse destroys them.
How intense are those X-ray pulses?
“They are about a hundred times more intense than what you would get if you focused all the sunlight that hits the Earth’s surface onto a thumbnail,” said LCLS staff scientist and co-author Sebastien Boutet.
H/t reader kevin a.
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