Tabletop laser and ‘invisible’ wires achieve record efficiency in nuclear fusion reactor

16 Mar 2018

The target chamber (front) and ultra-high intensity laser (back) used in the micro-scale fusion experiment at Colorado State University. Image: Advanced Beam Laboratory/Colorado State University

Using small but powerful lasers, a team of researchers has achieved a substantial breakthrough with record efficiency in a micro-scale nuclear fusion reactor.

Physicists from Colorado State University (CSU) have taken us another step closer to achieving near-limitless, clean energy with nuclear fusion following a breakthrough that replaces equipment valued at hundreds of millions of dollars with something that can fit on a tabletop.

The team led by Jorge Rocca detailed in a paper published to Nature Communications how it achieved record efficiency in a scaled-down version of a nuclear reactor using a small but powerful laser to heat arrays of ordered nanowires.

Future Human

By using its fast, pulsed laser to irradiate a target of invisible wires, the resulting reaction instantly creates extremely hot, dense plasmas similar in conditions to the centre of the sun.

These plasmas then drive fusion reactions, giving off helium and flashes of energetic neutrons at an astonishing level of efficiency – 500 times better than experiments using conventional flat targets from the same material.

The key to the team’s success is using a material called deuterated polyethylene for the nanowires. It is similar to the widely used polyethylene plastic, but its common hydrogen atoms are substituted by deuterium, a heavier kind of hydrogen atom.

Similar attempts at laser-driven controlled fusion experiments have only been achieved using significantly larger set-ups with multi-hundred-million-dollar lasers housed in stadium-sized buildings.

15 years away

The news comes just a few days after it was revealed that we could be much closer to the first nuclear fusion reactor hooked up to a public grid.

According to a team from MIT, this reality could be achieved in as little as 15 years using a new class of high-temperature superconductors as part of an experiment called Sparc.

The superconducting material consists of steel tape coated with a compound called yttrium barium copper oxide, allowing researchers to create powerful magnets but at a scale smaller than in existing reactors.

As a nuclear fusion reactor tries to replicate the process of the sun on a much smaller scale, these magnets are crucial to holding the plasma in place to prevent it from coming into contact with the surrounding chamber, as well as reducing the amount of energy needed to be put into the reactor.

If a sustained and stable nuclear fusion power reactor is achieved, it would usher in a new age of near-limitless, cheap and clean energy.

Colm Gorey was a senior journalist with Silicon Republic