Energy crisis lifeline: Laser and seawater plot leads to ‘no long-lasting waste’
2Energy crisis lifeline: Laser and seawater plot leads to ‘no long-lasting waste’
A GERMAN start-up is looking to create vast amounts of energy via a nuclear fusion process driven by the use of ultra-short laser pulses and fuel which can largely be extracted from seawater.
Conventional atomic power — nuclear fission — works by firing a neutron at a large, unstable atom like uranium-235, causing the latter to split, releasing a larger amount of energy, two smaller atoms, and additional neutrons. These neutrons proceed to hit and split more atoms, which release more neutrons, splitting more atoms — creating a chain reaction which releases significant amounts of energy. While fission is highly effective, it produces radioactive waste as an undesirable by-product, and comes within the inherent risk that an accident could lead to an uncontrolled chain reaction and a devastating nuclear reaction.
A potentially cleaner and safer alternative comes in the form of nuclear fusion, which produces large amounts of energy via the combining of lighter atoms like isotopes of hydrogen rather than the breakdown of heavier elements like uranium.
This is the same process that operates in the heart of stars like the Sun, where extreme temperatures in the order of tens of million degrees can force atoms to overcome their mutual electrostatic repulsion so that they can come together and fuse.
The main challenge of realising fusion commercially, therefore, lies in creating these extreme conditions here on Earth — which one approach involves trying to contain a super-hot plasma with magnetic fields.
As German investor Moritz von der Linden told the Times: “I always like to compare it to a pot of tomato sauce.
“If you put a pot of tomato sauce on your stove and you put it on at full throttle, the sauce starts heating up and starts moving.
“The problem is if you leave it on full throttle it’s going to end up on your ceiling.”
Mr von der Linden’s latest venture — Marvel Fusion, which was founded in 2019 — is taking a different tack when it comes to initiating atomic fusion.
Their approach involves firing brief but powerful pulses of laser light, each but a 30 quadrillionth of a second long, at a dense pellet of hydrogen and the isotope boron-11.
This causes the atoms to fuse together, producing three positively-charged helium atoms that repel each other, flying apart at nearly a third of the speed of light.
The energy of this “explosion” can then be captured through such technologies as heat exchange or an electrostatic field.
In theory, because each repeated reaction is so short, it is self-contained — meaning that the team’s fusion power concept doesn’t need the elaborate magnetic confinement setups that have hindered previous attempts to bring fusion power to reality.
Mr von der Linden continued: “Coming back to my tomato sauce analogy, we don’t need to heat up the tomato sauce.”
Instead, he explained: “We flick every atom in the sauce and give it extreme kinetic energy.
“This method is extremely efficient, it doesn’t create any long-lasting nuclear waste and the energy harvesting is very straightforward. There is no need for complex shielding.”
To date, however, Marvel Fusion has only carried out computer simulations and laser tests at their facilities in Bavaria, Colorado and Texas.
They do not expect to have a practical, working reactor prototype — let alone a commercially viable power station — until sometime near the end of the present decade.
The promise of Marvel Fusion’s approach, however, have already attracted tens of millions of euros in investment from firms including Siemens Energy and the French engineering conglomerate Thales — as well as the interest of Professor Gérard Mourou, who shared the 2018 Nobel Prize in Physics for his work on ultrashort-pulse, high intensity lasers.
Other organisations are also investing in fusion. Back in February, the Joint European Torus (JET) reactor in Oxfordshire reported achieving a record-breaking 59 megajoules of sustained fusion power over the course of around five seconds.
Mr von der Linden explained, however, that he would like to see EU officials investing more in fusion to provide energy security for the future.
He said: “Our hope is that European governments will see the necessity to take an open-minded approach to the technology required to solve the current energy crisis.
“While wind and solar are welcome, they won’t be sufficient to meet energy demand in the long run.”