Physicists develop highly efficient laser heating mechanism

Theoretical physicists from Imperial College London have devised an extremely rapid heating mechanism that they believe could heat certain materials to 10 million degrees Celsius in a fraction of a second, according to a study released Friday by the university.

The method could be relevant to new avenues of research in thermonuclear fusion energy.

The heating would be about 100 times faster than rates currently seen in fusion experiments using the world's most energetic laser system at the Lawrence Livermore National Laboratory in California, according to the study.

Researchers have been using high-power lasers to heat material as part of the effort to create fusion energy for many years.

When lasers are used to heat most materials, the energy from the laser first heats up the electrons in the target. These in turn heat up the ions, particles which make up the bulk of matter, making the process slower than targeting the ions directly.

The Imperial team discovered that when a high-intensity laser is fired at a certain type of material, it will create an electrostatic shockwave that can heat ions directly.

"One of the problems with fusion research has been getting the energy from the laser in the right place at the right time. This method puts energy straight into the ions," said the paper's lead author Dr. Arthur Turrell.

The heating is so fast in part because the material targeted is so dense. The ions are squeezed together to almost 10 times the usual density of a solid material as the electrostatic shockwave passes, causing the frictional effect to be much stronger than it would be in a less-dense material, such as a gas, according to the study.

Researchers said the technique, if proven experimentally, could be the fastest heating rate ever demonstrated in a lab for a significant number of particles. Endit