Nav: Home

X-ray pulses create 'molecular black hole'

May 31, 2017

Scientists have used an ultra-bright pulse of X-ray light to turn an atom in a molecule briefly into a sort of electromagnetic black hole. Unlike a black hole in space, the X-rayed atom does not draw in matter from its surroundings through the force of gravity, but electrons with its electrical charge - causing the molecule to explode within the tiniest fraction of a second. The study provides important information for analysing biomolecules using X-ray lasers, as the scientists report in the journal Nature.

The researchers used the free-electron laser LCLS at the SLAC National Accelerator Laboratory in the US to bath iodomethane (CH3I) molecules in intense X-ray light. The pulses reached intensities of 100 quadrillion kilowatts per square centimetre. The high-energy X-rays knocked 54 of the 62 electrons out of the molecule, creating a molecule carrying a positive charge 54 times the elementary charge. "As far as we are aware, this is the highest level of ionisation that has ever been achieved using light," explains the co-author Robin Santra from the research team, who is a leading DESY scientist at the Center for Free-Electron Laser Science (CFEL).

This ionisation does not take place all at once, however. "The methyl group CH3 is in a sense blind to X-rays," says Santra, who is also a professor of physics at the University of Hamburg. "The X-ray pulse initially strips the iodine atom of five or six of its electrons. The resulting strong positive charge means that the iodine atom then sucks electrons away from the methyl group, like a sort of atomic black hole." In fact, the force exerted on the electrons is considerably larger than that occurring around a typical astrophysical black hole of ten solar masses. "The gravitational field due to a real black hole of this type would be unable to exert a similarly large force on an electron, no matter how close you brought the electron to the black hole," says Santra.

The process happens so quickly that the electrons that are sucked in are then catapulted away by the same X-ray pulse. The result is a chain reaction in the course of which up to 54 of iodomethane's 62 electrons are torn away - all within less than a trillionth of a second. "This leads to an extremely high positive charge building up within the space of a ten-billionth of a metre. That rips the molecule apart," says co-author Daniel Rolles of DESY and Kansas State University.

Observing this ultra-fast dynamic process is highly significant to the analysis of complex molecules in so-called X-ray free-electron lasers (XFEL) such as the LCLS in California and the European XFEL, which is now going into service on the outskirts of Hamburg. These facilities produce extremely high-intensity X-rays, which can be used, among other things, to determine the spatial structure of complex molecules down to the level of individual atoms. This structural information can be used by biologists, for example, to determine the precise mechanism by which biomolecules work. Other scientists have already shown that the molecules reveal their atomic structure before exploding. However, to study the dynamics of biomolecules, during photosynthesis for example, it is important to understand how X-rays affect the electrons.

In this study, iodomethane serves as a model system. "Iodomethane is a comparatively simple molecule for understanding the processes taking place when organic compounds are damaged by radiation," says co-author Artem Rudenko from Kansas State University. "If more neighbours than a single methyl group are present, even more electrons can be sucked in."

Santra's group at CFEL has for the first time managed to describe these ultra-high-speed dynamics in theoretical terms, too. This was made possible by a new computer program, the first of its kind in the world. "This is not only the first time that this experiment has been successfully carried out; we even have a numerical description of the process," points out co-author Sang-Kil Son from Santra's group, who was in charge of the team that developed the computer program. "The data are highly relevant to studies using free-electron lasers, because they show in detail what happens when radiation damage is produced."

Apart from DESY, Kansas State University and SLAC, Tohoku University in Japan, the Max Planck Institute for Nuclear Physics in Germany, the University of Science and Technology Beijing in China, the University of Århus in Denmark, Germany's national metrology institute Physikalisch-Technische Bundesanstalt, the Max Planck Institute for Medical Research in Germany, the Argonne National Laboratory in the US, Sorbonne University in France, the Brookhaven National Laboratory in the US, the University of Chicago in the US, Northwestern University in the US and the University of Hamburg in Germany were also involved in the study.

Deutsches Elektronen-Synchrotron DESY is the leading German accelerator centre and one of the leading in the world. DESY is a member of the Helmholtz Association and receives its funding from the German Federal Ministry of Education and Research (BMBF) (90 per cent) and the German federal states of Hamburg and Brandenburg (10 per cent). At its locations in Hamburg and Zeuthen near Berlin, DESY develops, builds and operates large particle accelerators, and uses them to investigate the structure of matter. DESY's combination of photon science and particle physics is unique in Europe.
-end-
Reference:

Femtosecond response of polyatomic molecules to ultra-intense hard X-rays; A. Rudenko, L. Inhester, K. Hanasaki, X. Li, S.J. Robatjazi, B. Erk, R. Boll, K. Toyota, Y. Hao, O. Vendrell, C. Bomme, E. Savelyev, B. Rudek, L. Foucar, S.H. Southworth, C.S. Lehmann, B. Kraessig, T. Marchenko, M. Simon, K. Ueda, K.R. Ferguson, M. Bucher, T. Gorkhover, S. Carron, R. Alonso-Mori, J.E. Koglin, J. Correa, G.J. Williams, S. Boutet, L. Young, C. Bostedt, S.-K. Son, R. Santra, and D. Rolles; Nature, 2017; DOI: 10.1038/nature22373

Deutsches Elektronen-Synchrotron DESY

Related Black Hole Articles:

Scientists make waves with black hole research
Scientists at the University of Nottingham have made a significant leap forward in understanding the workings of one of the mysteries of the universe.
Collapsing star gives birth to a black hole
Astronomers have watched as a massive, dying star was likely reborn as a black hole.
When helium behaves like a black hole
A team of scientists has discovered that a law controlling the bizarre behavior of black holes out in space -- is also true for cold helium atoms that can be studied in laboratories.
Star in closest orbit ever seen around black hole
Astronomers have found evidence of a star that whips around a likely black hole twice an hour.
Tail of stray black hole hiding in the Milky Way
By analyzing the gas motion of an extraordinarily fast-moving cosmic cloud in a corner of the Milky Way, Astronomers found hints of a wandering black hole hidden in the cloud.
Hubble gazes into a black hole of puzzling lightness
The beautiful spiral galaxy visible in the center of the image is known as RX J1140.1+0307, a galaxy in the Virgo constellation imaged by the NASA/ESA Hubble Space Telescope, and it presents an interesting puzzle.
Clandestine black hole may represent new population
Astronomers have combined data from NASA's Chandra X-ray Observatory, the Hubble Space Telescope and the National Science Foundation's Karl G.
When will a neutron star collapse to a black hole?
Astrophysicists from Goethe-University Frankfurt have found a simple formula for the maximum mass of a rotating neutron star and hence answered a question that had been open for decades.
Behemoth black hole found in an unlikely place
Astronomers have uncovered a near-record breaking supermassive black hole, weighing 17 billion suns, in an unlikely place: in the center of a galaxy in a sparsely populated area of the universe.
Behemoth black hole found in an unlikely place
Astronomers have uncovered one of the biggest supermassive black holes, with the mass of 17 billion Suns, in an unlikely place: the centre of a galaxy that lies in a quiet backwater of the Universe.

Related Black Hole Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Jumpstarting Creativity
Our greatest breakthroughs and triumphs have one thing in common: creativity. But how do you ignite it? And how do you rekindle it? This hour, TED speakers explore ideas on jumpstarting creativity. Guests include economist Tim Harford, producer Helen Marriage, artificial intelligence researcher Steve Engels, and behavioral scientist Marily Oppezzo.
Now Playing: Science for the People

#524 The Human Network
What does a network of humans look like and how does it work? How does information spread? How do decisions and opinions spread? What gets distorted as it moves through the network and why? This week we dig into the ins and outs of human networks with Matthew Jackson, Professor of Economics at Stanford University and author of the book "The Human Network: How Your Social Position Determines Your Power, Beliefs, and Behaviours".