X-ray laser reveals how radiation damage arisesAn international research team has used the X-ray las
X-ray laser reveals how radiation damage arises
An international research team has used the X-ray laser European XFEL to gain new insights into how radiation damage occurs in biological tissue. The study reveals in detail how water molecules are broken apart by high-energy radiation, creating potentially hazardous radicals and electrically charged ions, which can go on to trigger harmful reactions in the organism. The team led by Maria Novella Piancastelli and Renaud Guillemin from the Sorbonne in Paris, Ludger Inhester from DESY and Till Jahnke from European XFEL is presenting its observations and analyses in the scientific journal Physical Review X.
Sincewater is present in every known living organism, the splitting of the water molecule H2O by radiation, called the photolysis of water, is often the starting point for radiation damage. “However, the chain of reactions that can be triggered in the body by high-energy radiation is still not fully understood,” explains Inhester. “For example, even just observing the formation of individual charged ions and reactive radicals in water when high-energy radiation is absorbed is already very difficult.”
To study this sequence of events, the researchers shot the intense pulses from the X-ray laser at the water vapor. Water molecules normally disintegrate on absorbing a single such high-energy X-ray photon. “Due to the particularly intense pulses from the X-ray laser, it was even possible to observe water molecules absorbing not just one, but two or even more X-ray photons before their debris flew apart,” Inhester reports. This gives the researchers a glimpse of what goes on inside the molecule after the first absorption of an X-ray photon.
