New machines for fusion research | Thomas Klinger | TEDxBrussels

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Plasma physicist Thomas Klinger is dealing with the fundamental principles of a future power plant, which – like the Sun – will produce energy from the fusion of light atomic nuclei. Embedded in an international endeavor, this requires the design and construction of large research facilities such as ITER and Wendelstein 7-X to develop the knowledge base for the exploitation of a new clean and abundant primary energy source.

Thomas Klinger is head of the "Stellarator Dynamics and Transport" Division and since 2005 scientific director of the project "Wendelstein 7-X" as well as member of the Directorate of IPP.

The Wendelstein 7-X (W7-X) reactor is an experimental stellarator (nuclear fusion reactor) built in Greifswald, Germany, by the Max Planck Institute of Plasma Physics (IPP).

In April 2001, he was appointed as Scientific Member of the Max-Planck Society and Director at the Max-Planck-Institute of Plasma Physics (IPP) in Greifswald.

After a research period in France he obtained his PhD in 1994 with a thesis on non-linear plasma dynamics. As a research assistant at the University of Kiel, Klinger was concerned with drift wave turbulence and nonlinear plasma structures. As visiting scientist he conducted research at the Alfvén Laboratory in Stockholm, the Centre de Physique Théorique and the Université Aix-Provence in Marseille and the Max-Planck-Institute of Plasma Physics in Garching. He obtained his habilitation in 1998 with a thesis on the control of plasma instabilities. Shortly thereafter he was appointed Professor of Experimental Physics at the Ernst-Moritz Arndt University, Greifswald, where he has headed the Institute of Physics as chair from 2000 till 2001.

What is behind me
is the powerhouse of the Universe.

It is just a conventional star.

It is our Sun.

And this power station
has been running for billions of years,

reliably delivering energy to us
and to the rest of the Universe

just by light emission.

So, that's a very nice thing,
and it obviously runs,

and the mechanism
through which it runs is fusion,

and I'm going to explain to you
something about that.

But I will also ask the question:

can we bring this mechanism
on Earth directly?

And the answer is no, by no means.

The Sun is too big, the Sun is too hot,
the Sun is too dense,

everything speaks against that;

but... and the story about the but:

we have to build machines,
clever machines;

we, humans have to build machines

in order to mimic this process,
in order to bring it on Earth.

So, for that, we have to understand
a few little things of physics.

Don't be afraid.

You have to carefully distinguish
between fission and fusion.

Fission is splitting heavy nuclei;
fusion is fusing light nuclei.

And they both belong to the same process:

it's a conversion of mass into energy,

and that's Einstein's
famous formula E=mc²,

and that's the common mechanism.

And this energy is released just by speed,
by kinetic energy, by heat in other words.

So it generates heat.

And that's what we would like
to make use of.

And for that, we have to use a trick.

Instead of using conventional hydrogen,
we use versions of hydrogen.

And these two so-called isotopes
are called deuterium and tritium.

Deuterium is just heavy hydrogen,
tritium is super heavy hydrogen.

They both are actually hydrogen isotopes,

they behave like hydrogen,
just the mass is different.

And you can much more easily fuse them
than conventional hydrogen,

than the hydrogen we know
from the everyday world.

And when we fuse them, they collide,

and in the collision, they generate
a helium nucleus, an alpha particle,

and a neutron, and lots of energy.

And that's the process we would like
to make use of; we, fusion scientists.

And in order to get a feeling
what is this fuel about:

fusing one gram of deuterium-tritium

releases the same energy
as burning 10 million grams of coal.

And so, that's a fantastic fuel.

And so, you can say: is it available
on Earth, or is it just a dream?

And the answer is yes,
it is basically available.

So, deuterium is found just in seawater,
in a low concentration,

but we do not need much.

Tritium is available on Earth

by making use of a mechanism

that generates tritium from lithium.

And so, if you now
put everything together,

you can say that a half-filled
bath tub of water and an accumulator -

here, there's a lithium-ion
accumulator in this mobile phone -

would release enough energy

to supply an average European
for 25 years with electric energy.

That's of course, a big, big promise.

How to make it happen?

And this big promise has driven
mankind for 50 years already

to explore how it can work.

And this diagram here shows
the early days of fusion research.

It's from the 1950s,
so that's from Los Alamos [Lab]

and they built a device, a machine.

And there is this ring in the background -

at the center of the photo,
there's a ring with a purple glow -

and this ring, together with
what's surrounded by

was called the Perhapsatron -

and that's because the scientists
didn't know if it would work at all.

It worked somehow, but not sufficiently,

because the very basic problem of fusion
is fusion is very easy to do.

The fundamental nuclear process
is known, and it's easy to do.

The exercise is to make a lot
of fusion processes at the same time.

Again, so we need a lot of fusion

in order to generate
substantial amounts of energy.

And so, it became obvious

that one has to work on different things
in order to build the right machine.

The Perhapsatron not being
the right machine was discarded.

Many, many others followed,
other generations followed,

and I would like to give you
an update on the current status.

So, the magnetic field is very important:

you have to make use of the magnetic field

in order to confine this super hot gas
which we call plasma.

And you might have seen a plasma
already in reality

if you have seen the Northern Lights
or an Aurora Borealis.

That's a photo through
the window of an airplane

of the Aurora Borealis
over the Northern Pole.

The structure of the Aurora Borealis -

this stripe-like structure is given
by the magnetic field of the Earth.

So this is naturally occurring.

And the plasma is actually the ingredient
that's the boiling soup

that makes fusion happen
so many times as it should be

in order to really gain energy.

That's in the kind of standard machine.

We are building a fusion science:

it is called tokamak -
tokamak not tomahawk;

that's a big difference!

The tokamak consists
of superconducting coils

in which a very strong current is running.

It is also based on a strong current
running in the actual plasma,

and the plasma is ring-shaped.

So this purple ring there,

or this magenta ring shown there,

is the actual plasma
that is attached to the magnetic field.

That's the basic principle of a tokamak,

and nowadays,

we are brave enough
in fusion research to build big machines,

because they must be big in order to have
a lot of fusion reactions.

The biggest tokamak in the world,
now under construction,

is the tokamak ITER
in the South of France.

And it's a world tokamak in a sense.

It's not only a big tokamak,
the biggest tokamak in the world,

but it's also a world project,

because in the ITER project,
half of mankind is involved:

China, the USA, Russia, the EU,
India, Japan, and South Korea.

They're all joining forces
in order to build

this really big superconducting
tokamak in the South of France.

And this machine is going
to start operating in 2025.

This is a big, big project.

There's another concept
which is called a stellarator.

Stellarator means bringing
the [power of] a star on Earth.

And here, in blue again,
the magnets are shown

that generate a magnetic field.

And in yellow,

that's the shape of the plasma
given by the magnetic field geometry.

Stellarators need optimization.

What does optimization mean?

Optimization means
setting up a number of criteria:

good plasma stability,
improved heat insulation,

equilibrium, confinement,
things like that.

And you cast everything,
all these requirements,

in a set of computer codes -

very massive computer codes
with a lot of plasma theory in it -

and then you have to do

all these horribly complicated
calculations using supercomputers.

And the supercomputer

that has calculated the Wendelstein 7-X -
that's our stellarator -

was the Cray X-MP.

This device has more computer power
than the Cray X-MP -

this goes back to the mid 80s,
and supercomputers look different now -

but nevertheless,

the computing power was sufficient
to determine the shape of the coils.

These calculations were repeated
and confirmed many times,

and so we are pretty confident

that we have found
the right magnetic field.

The Wendelstein 7-X stellarator
consists now of the following elements:

the plasma - so that's
the shape of the plasma,

it looks a little bit like
a twisted tire of a bicycle -

the magnetic field coils,
these calculated magnetic field coils;

another set of coils
to change the magnetic field a little bit;

a massive steel structure
that carries these coils -

each coil weighs six tonnes
and has a diameter of three meters -

and of course,
also many pipes and connectors

to connect the magnet system together;

and also an outer vessel -

it's a massive steel vessel

because the coils
have to be operated in vacuum

since, for superconductivity,

you have to cool down the coils
to minus 270 degrees centigrade.

That's then the outer shape
of the machine.

It looks a little bit like a spaceship,

So the "Science" magazine wrote

it looks like
Han Solo’s Millennium Falcon,

and they also wrote
this machine was designed in hell.

It's all not true;

it's just a kind of engineering exercise,
and that's the machine in reality.

And you also have
the comparison to a person.

It is a complicated machine.

Four hundred technicians,
engineers, and scientists

have worked 20 years to build the machine
in Greifswald, Northern Germany.

Twenty years, one million assembly hours.

And the machine is running.

We were pushing the button,

and the physicists in the center
did the job for us.

In the inset, you also see the plasma.

The plasma is glowing nicely
bluish and reddish.

These are different stages
of the plasma development.

The machine runs perfectly fine.

That's very satisfying
after 20 years of construction,

and we are putting a lot of hope
on the performance of this machine.

And here's the performance:

0.01 grams of hydrogen
were injected into the vessel,

heated up with 4 million watts
of microwave power

to 100 million degrees centigrade
for the electrons

and 20 million degrees centigrade
for the hydrogen.

That wasn't that bad
for the first step of the machine.

We have to increase
the particle density by a factor of 5,

which sounds easy,

but it needs more heating power.

We are currently upgrading the machine
to increase the heating power

to ten million watts, to ten megawatts,
for ten-second pulses,

and later on, also for longer ones.

I would like to conclude.

I would like to make
a case here for fusion.

Fusion is clean;

it has no CO₂ emission -
keyword 'climate change';

no long term waste -
different from fission;

it is abundant - enough fusion fuel
for millions of years;

and it's accessible to everybody -

so nobody owns the fusion fuel,
which is very important, of course;

it's safe - there are
no catastrophic failures possible;

and it's economic -

the machines are expensive,
but the fuel cost is essentially zero.

Two key machines in the world are:

Wendelstein 7-X -

here the mission is to help create
a hydrogen plasma for 30 minutes,

and this has never been done before,
the standard is a few seconds up to now;

and the ITER mission
is to create a fusion plasma

which generates ten times more energy
than needed to create plasma.

I think that will be a major breakthrough,

and then, we have
a new primary energy source,

and I should say

this is the only new primary energy source
mankind is working on.

Thank you for your attention.

(Applause)