This is the Guardian. Today we're here to talk about fusion. A few days ago scientists from the US National Ignition Facility in California announced a major breakthrough in nuclear fusion.

Combining two particles into one.

For the first time since research began in the 1950s,

an experiment released more energy than was pumped into it,

a massive achievement known as ignition or energy gain.

Simply put, this is one of the most impressive scientific feats of the 21st century.

There are hopes that fusion could pave the way for near limitless clean energy in the future.

But what exactly is nuclear fusion?

What have research has achieved already?

And how long until it's powering our toasters. I'm the

Guardian Science Editor Ian's sample and this is Science Weekly. Nalenbekkah, you're head of engineering at EITA, the International Nuclear

Fusion Research Project in France. Now let's start with the basics.

What is Nuclear Fusion?

So Nuclear Fusion is one of the nuclear processes that we can exploit in order to get energy out of the matter.

The one we are already exploiting is nuclear fission, which consists in trying to break the big nuclei's and get energy out of them.

And this second branch of nuclear reaction is about having very small nuclei colliding, getting stuck together, and this also creates

energy out of it. This is the energy that is essentially driving all the stars in the universe. We are trying to reproduce a small part of the sun and to put it in a box here on earth.

And what kinds of fuels are used in these fusion reactions in the lab?

What are you putting into the system, if you like?

And are you getting a lot of waste products coming out?

The fuel is the small nuclei. The ones that we are trying to use on Earth

are two isotopes of the hydrogen, so two, let's say, variant of the hydrogen, the one that is called uterium and the one that is called

...