Researchers at Argonne National Laboratory have, for the first time, used attosecond laser pulses to watch how electrons behave inside liquid water molecules as they ionize. This breakthrough offers a clearer picture of how radiation interacts with human body cells and with everyday materials, shedding light on fundamental processes behind radiation effects. The work is connected to ongoing efforts at Pacific Northwest National Laboratory to understand radiation phenomena.
The experiments leveraged the LCLS X-ray laser, a high-energy facility that emits tightly focused X-ray beams. A specially designed setup allows researchers to generate ultra-thin water films and place them directly in the beam’s path, enabling precise observation of the interaction between moisture and X-rays.
In this arrangement, researchers exposed the water samples to two distinct sequences of X-ray pulses. One sequence ionized a portion of the water molecules, while the other provided a readout of how electrons behaved immediately after ionization. The attosecond-scale duration of these pulses captured the fleeting moment when electron dynamics change in response to radiation, while the atomic nuclei remained comparatively still for that ultrashort instant.
The resulting data indicate that liquid water behaves as a single, uniform phase under these conditions, challenging earlier indications from femtosecond and picosecond laser experiments that suggested multiple structural phases. This simplification helps streamline subsequent investigations into the physical properties of liquid water and water-based media, which are critical for chemistry, biology, and materials science.
Physicists are exploring new ways to harness energy beams to address hazardous chemicals. In related lines of inquiry, researchers are examining how targeted irradiation might disrupt or destroy certain toxic compounds at the molecular level while preserving surrounding materials, a line of work with potential environmental and health implications.