World`s fastest water-heating method developed?

Scientists, including one of Indian-origin, have devised a new technique to boil water in less than a trillionth of a second.

PTI| Updated: Dec 17, 2013, 19:36 PM IST

Berlin: Scientists, including one of Indian-origin, have devised a new technique to boil water in less than a trillionth of a second.

The theoretical concept, which has not yet been demonstrated in practice, could heat a small amount of water by as much as 600 degrees Celsius in just half a picosecond (a trillionth of a second).

That is much less than the proverbial blink of an eye: one picosecond is to a second what one second is to almost 32 millennia. This would make the technique the fastest water-heating method on Earth.

All it takes for superfast water heating is a concentrated flash of terahertz radiation. Terahertz radiation consists of electromagnetic waves with a frequency between radio waves and infrared.

Terahertz flashes can be generated with devices called free-electron lasers that send accelerated electrons on a well defined slalom course. The particles emit electromagnetic waves in each bend that add up to an intense laser like pulse.

The terahertz pulse changes the strength of the interaction between water molecules in a very short time, which immediately start to vibrate violently.

The scientists from the Hamburg Center for Free-Electron Laser Science calculated the interaction of the terahertz flash with bulk water.

The simulations were performed at the Supercomputer Center Julich and used a total of 200,000 hours of processor time by massively parallel computing.

"We have calculated that it should be possible to heat up the liquid to about 600 degrees Celsius within just half a picosecond, obtaining a transiently hot and structureless environment still at the density of the liquid, leaving all water molecules intact," said Dr Oriol Vendrell from the Center for Free-Electron Laser Science (CFEL), a cooperation of Deutsches Elektronen-Synchrotron (DESY), the University of Hamburg and the German Max Planck Society Vendrell.

The concept opens up interesting new ways for experiments with heated samples of chemical or biological relevance.

The novel method can only heat about one nanolitre (billionth of a litre) in one go. This may sound small, but is large enough for most experiments.

"The idea is to heat-up the `solvent` so that many molecules start the desired chemical process at the same time and then watch the reaction evolve," said Vendrell, who worked out the super heater with co-authors Pankaj Kr Mishra and Professor Robin Santra, also of CFEL.

Although the hot mini-cloud will fly apart in less than a millisecond, it lasts long enough to unravel everything of interest in thermal reactions such as the combination of small organic molecules to form new substances.

The reaction progress can be probed with ultrashort X-ray flashes like they will be produced by the 3.4-kilometre-long X-ray free-electron laser European XFEL, which currently is being built between the DESY campus in Hamburg and the neighbouring town of Schenefeld.