news.com.au NOVEMBER 13, 2016
IT’S known as the Z Machine and the only thing more impressive than the way it looks is how it works — and it might just hold the key to revolutionising the world’s energy sources.
The massive machine tucked away in a facility in Albuquerque, New Mexico is designed to essentially create the conditions that birth stars and could one day provide a way to harness fusion energy.
Fusion is a nuclear reaction in which atomic nuclei of low atomic number fuse to form a heavier nucleus with the release of huge amounts of energy.
By conducting experiments scientists hope to one day be able to harness that power and usher in a new form of clean energy.
There are a number of major projects — most notably in California, Germany, and France — working on experiments to forge the new frontier of fusion science.
The forefront of the global effort in nuclear fusion energy is a project in the south of France called ITER, or the International Thermonuclear Experimental Reactor.
It is a collaboration between 35 countries including Australia that is 50 years in the making and aims to replicate how the sun produces energy here on Earth.
The incredible machine is still years away from getting switched on but when it does it will generate a super-hot cloud of hydrogen that will rotate faster than the speed of sound while being bombarded with surges of electric current causing the core of the machine to reach temperatures up to 200 million degrees Celsius.
However, the spectacularly-named Z Machine works with a different method and is designed to create radiation and high magnetic pressure, which are both applied to a variety of scientific purposes ranging from weapons research to the pursuit of fusion energy.
Roughly speaking, the breathtaking piece of equipment at the Sandia National Laboratories in the US works by firing huge amounts of electricity (more than 20 lightning bolts of energy) from about 26 million amps through a tiny fuel-filled cylinder about the size of a thimble.
With a flick of a switch the massive surge of electrical current creates an overwhelming magnetic field.
According to the journal Science, the magnetic field pinches the cylinder “so fast and furiously that hydrogen atoms inside fuse into helium, releasing a blast of high-energy neutrons and helium nuclei.”
The below image is the only photo to ever be captured of the blast.
When it gets fired up, it’s powerful enough to cause a mini earthquake that can be felt across the site of the facility.
According to its operators, the Z machine is the largest pulse powered device in the world and is also the largest x-ray generator in the world.
“As an unconfined event, fusion has long been used in the development of weapons. Its great potential as a new source of energy, which depends on scientists’ ability to harness its power in laboratory events, continues to be explored. The Z machine is central to that effort,” the Sandia National Laboratories website says.
However the Z machine, and similar facilities such as California’s National Ignition Facility which uses lasers to heat and compress small amounts of hydrogen fuel, are much more likely to create uses in weaponry rather than clean energy, according to John Howard, the head of the Plasma Research Laboratory at the ANU College of Physical and Mathematical Sciences.
“There are a few different approaches to fusion. One is through magnetic fusion which is what ITER is all about,” he said. “Another is using just inertia, in other words you implode a target in such a short amount of time that the hot plasma hasn’t got a chance to escape before the fusion occurs, so it’s more like a nuclear bomb.”
That’s why the Z machine, while working in fusion energy, its primary purpose is high energy density physics and thus is more likely to be used for validating models of nuclear weapons, Prof Howard said.
“As a viable fusion power source for the future, I think it’s unlikely … The real pathway to fusion is magnetic confinement fusion, and that’s what ITER is about.”
And for him it’s a pursuit of paramount importance.
“In my view if the world was fair dinkum about green house gases and alternative energy sources we’d be looking at nuclear energy in the short term and fusion energy in the long term,” he said.
“Fusion energy uses hydrogen out of sea water, so fuels are plentiful and it converts hydrogen into helium so the byproducts are safe, and it taps into the primordial processes that make the sun burn. The sun is really the source of all energy on Earth ultimately, so we want to tap into that primordial source of energy so we can build our own stars and harness our own energy in an effective and clean way.”
As yet we haven’t developed the technology to capture the power that will be generated by projects like ITER and allow us to channel it into electricity. But the world is working on the breakthrough and Australian researchers are playing a critical role.
Experts from the Australian Plasma Fusion Research Facility at the ANU including Prof Howard have been brought onto the project recently in a multi-million dollar made with the Australian government.
“Australia has come in through the back door because we developed technologies that are valuable for ITER,” Prof Howard said, adding he had just returned from the ITER site a few weeks ago.
While it won’t be ready to be switch on for years to come, “this is going to be the biggest physics experiment on the planet when it’s completed,” he said.
When ITER is switched on it will be the culmination of a long process that Australia has been involved in every step of the way.
In fact Australian scientist Mark Oliphant played a crucial role in the first experimental demonstration of nuclear fusion back during the interwar period.
For a long time the concept of turning that into energy was plagued by numerous problems and our scientific limitations.
To date, the problem facing scientists has been that nuclear fusion has produced less energy than the huge amount needed to produce the reaction — but ITER is hopefully set to change that.
“There have been a number of studies done … and I think commercially it looks like a viable proposition,” said Prof Howard.
At this stage it remains to be seen if scientists can pull it off. If they do it will be a very long time in the making, but the juice will most certainly be worth the squeeze.
