Delivering Fusion Energy

thank you

um so i’m a physicist you can probably

guess that there’s not many times i’ve

followed on cheerleaders

and i was watching them backstage and

they were absolutely phenomenal my heart

was racing

anyway um so yes i’m here to talk to you

today about

fusion energy this is not about me this

is about an idea

and hopefully by the end of the talk uh

you’ll be as convinced as i am

that that idea is uh is a worthy cause

um before we get on to that

let’s talk about the cheery subject of

climate change

now when i think about climate change

um i tend to adopt a similar manner to

this gentleman here and i’m sure many of

you

in the audience feel a bit the same and

i think the reason is

that it’s a very intangible subject it’s

a big

broad problem that will take millions of

people

over tens of years to solve and it’s

very hard for us to really

put that into context i’ll try and do

that here a bit for you

let’s so our goal should be to

decarbonize our energy supply we need to

not

rely on carbon-based fossil fuels to

produce energy

how do we do that or what does that

actually mean last year

globally we burnt 11 billion tons of oil

or 11 billion equivalent tons of oil

so if we want one year of

energy supply without carbon in our

energy

economy we need to displace 11 billion

tons of fossil fuels that’s the

challenge we’re facing

now we have there are innovations

underway to do this

um renewables renewables are fantastic

and they will definitely definitely play

a role

uh in the future the problem is with

renewals is reliability

what happens if the sun goes out we’re

very familiar with that here in the uk

what happens if the wind dies what

happens if the tides go out

we can’t rely on renewables for

continuous power supply we need to do

better and what we would really like

is a source of energy that is clean that

is safe

and that is continuous now luckily

mother nature has provided one for us

this is fusion fusion is the process

that powers the sun this is the sun

um we can see it today uh luckily i had

a lovely joke prepared

for just in the event that we couldn’t

see the sun today but i’ll leave that

one for next time

so fusion is the process by which two

very very small

atoms hydrogen in the case of the sun

move around

come in contact with one another bond

and form a new atom

uh in this case helium and because that

helium is

slightly less sways slightly less

than all of the parts that went in to

make it we can use equals mc squared

the most famous equation in science and

we get energy back

out of that and that’s fusion energy now

we’ve known about fusion for a little

while so fusion pioneer

sir athlete arthur stanley eddington

said in 1920 when he was describing this

energy

this resource can scarcely be other than

the subatomic energy which exists

abundantly in all matter

we sometimes dream that humanity will

one day learn how to release it and use

it for their service

the story is well nigh inexhaustible if

only it could be tapped

now at the time this was met with some

skepticism because people very quickly

realized that you needed intense

pressures

intense temperatures to get this to work

we do not argue with the critic he says

who urges

that stars are not hot enough for this

process we tell them

go find a hotter place now

eddington died in the 1940s and it’s a

real shame that he’s not around today

because actually we do know that in the

universe

there is a hotter place where we can be

reasonably certain that fusion does

occur

and it’s here in south oxfordshire this

is our lab in a little town called

column in south oxfordshire

and this in this building when it’s

running we have a machine called jet and

it is the hottest place in the solar

system

now the sun is a relatively inefficient

fusion reactor

which is very good because otherwise it

would have burnt out billions of years

ago and

we wouldn’t be in this pro in this mess

anyway but we need to do better here on

earth so we don’t use hydrogen we use

deuterium

which is one proton and one neutron and

this fuses

with tritium which is one proton and two

neutrons

and the byproduct of that is helium two

protons two neutrons

and a lonely neutron now this neutron

flight carries a huge amount of energy

with it and it flies out of the vessel

and will eventually heat some sort of

water blanket around a machine

drive a steam turbine now these fuels

are very abundant so about one in every

six thousand atoms of hydrogen in water

is actually deuterium

so you you take a bath in deuterium

tritium on the other hand is not very

abundant in nature it’s radioactive so

it doesn’t occur naturally

but we can make true tritium out of

lithium if we bombard lithium with

neutrons

we can make tritium and it turns out

that if we take all of the deuterium

in one bathtub of water all of the

lithium in one laptop

one laptop battery we’ve got enough

fusion energy there

to match 40 tons of coal or 250

kilograms of uranium

quite a lot this is enough to power your

home for 20 uh

40 years or 20 years if you’re an

american um

and to put it into more uk perspective

it’s enough to make

2.7 million cups of tea

now the most uh developed fusion reactor

that we have on earth is called the

tokamak

the tokamak uh was a device that came

out of russia in the 1950s and 60s

as you might have guessed from the name

up there that i’m not going to try and

pronounce

and the tokamak basically consists of

three key parts

at the center of the machine we have

something called a plasma now if you

take a gas and you heat that gas to

super high temperatures

all of the electrons in that gas are

going to split off from the atoms

and you’ve got a super of electrons

flying around ions flying around

interacting with each other

but no longer forming atoms that is a

plasma actually

plasmas are really really common so

something like 40 uh 97

of all matter in the known universe is

actually in the plasma state

um so we have a plasma at the center of

our machine it’s burning

at 150 million degrees and we have to

keep it there somehow

now because everything in the plasma is

charged

it reacts to a magnetic field and we can

use that to our advantage

so we place magnetic field coils all

around the machine that

um that apply a kind of magnetic cage to

this plasma and keep it in place

now that’s all well and good but we

don’t want to do that in the air

because air contains lots of nasty

things like oxygen

so we don’t want to use air so we keep

everything in

a vacuum and this is basically what a

tokamak is it’s a plasma

in a vacuum vessel housed in a magnetic

cage

now we’ve known about tocomax for about

50 or 60 years

and we’ve sunk a lot of money worldwide

into this research

and you as taxpayers except the students

in the audience

you would be well within your rights to

ask

why don’t we have fusion now where is

fusion well actually we’re very lucky

that we

can finally say that fusion is entering

the delivery era

this is eta eta is currently being built

in the south of france

and ita will be the proof of principle

eta is a 35-year collaboration

between seven partners china the eu

india japan south korea russia and the

united states

about 50 percent of all of the world’s

population is represented in ita and

about 90 percent of the world’s economy

is represented anita so it’s a massive

massive scale project

it’s costing 25 billion euros which is

as much as five

large hadron colliders or one house in

inner city london

eta is monumental in every respect it’s

about the same size as a football

stadium the whole complex

the magnets anita can levitate an

aircraft the heating systems in eta

could vaporize a car in seconds it

really is in every respect

pushing the technological capabilities

of mankind right to their very limits

so why are we doing it eta will produce

10 times the power

out from fusion energy than we put into

the machine so we’re going to multiply

the energy we put into this machine by

10 times

which is great but more importantly it

is going to produce something we call a

plasma burn

and a plasma burn occurs when the heat

inside the plasma is enough

to keep that reaction sustained so we he

we

chucked some heat into the plasma some

fusion happens

and it self heats and it keeps itself

going

and once we achieve that the

possibilities are pretty much

endless as long as we can keep this

thing contained

now eta is the solution

the problem not the problem eater is the

proof

but eater is not the solution the reason

that eater is not the solution

is because it’s too expensive for the

amount of power it’s producing

we need to do better if we’re going to

build commercial fusion reactors

and we’ve identified six challenges more

or less

that stand in the way block this kind of

commercialization

going from one to six these are we have

to make the hot bits really hot we have

to achieve these burning plasmas at 150

million degrees

we have to build the machine out of

materials that can withstand the

intense environment that we’re putting

them in so this is a really a not nice

environment to be placing materials in

some most of that heat will used will

extract as energy and this is great this

is what we want to do but some of that

heat will remain in the system

and we have to be able to remove that

heat in a safe way that doesn’t damage

the machine

we also have to be able to be

self-sufficient so we have to produce

enough tritium

that we can keep the whole process going

without uh without

sort of fizzling out we say we can do

all of those four things and we’ve

successfully run the machine for six

months

we’re still going to have to repair it

and you don’t want to send people in to

do that it’s not a nice environment to

take a walk around

so we use robots and we have to uh do

all of this through remotely operated

robotic maintenance

and finally if you can do all of that

you will have to do all of that

in sync so you have to do you have to

solve all of those challenges

in a way that marries together and can

work all at the same time using

innovative manufacturing techniques

most of which we haven’t invented yet

this is the challenge that stands before

us

now it’s very nice to be able to stand

in front of you and say we’re addressing

all of these challenges right now and

for the last few minutes of my talk i’d

just like to go through three of them

where i think some really exciting

science is happening right now or will

be happening in the very near future

so i’ll talk a little bit about what

we’re doing to make plasmas burn

i’ll talk a little bit about how we

remove this heat from our systems

and i’ll talk a bit about some of the

robots that are doing the kind of dirty

work that we can’t do

so this is jet jet stands for the joint

european taurus

and jet is based at our lab down in

south oxfordshire and this is the

hottest place in the solar system

at the centre of this machine we’re

burning 150 million degrees

when it’s running at full power jet is

operated by

uh by us on behalf of the european

commission and when it’s running it

looks something like this

so you can see it’s booting up at the

moment and what’s really interesting

about this video

is that when it really kicks in you’re

going to start seeing the video

speckling you’re going to start seeing

pixels

look like something is going a bit wrong

with the camera can you see those there

it’s starting to speckle

now this isn’t the camera going wrong

what’s actually happening here

is fusion born in the center of this

machine is producing the neutrons

which are coming out and they’re hitting

the camera sensor and when those

neutrons are hitting the camera sensor

they’re killing those pixels for a few

seconds and the pixels are dying and

that’s what the speckling is and it’s a

really nice illustration

that we are doing fusion right now on a

regular basis in jet

now jet holds the record for fusion

power um in 1997

it got 65 percent of the power out that

we put in

not one not 10 but still getting close

um and jet is going to be doing these

experiments again very very soon so

at the end of this year at the start of

next year we’re going to be running

a dedicated fusion campaign we don’t

expect to beat

65 so we don’t think jet can do better

than that

but what we will what we do hope to do

is get that 65

but extend it over a nice controlled

range

and once we do that we can say that we

can operate this machine

at its peak performance in a controlled

manner

and that puts us in a really good

position from when for when eta comes

online

so we’re operating jet now really to

prepare us for the eta

um campaigns that are going to prove

that fusion is the energy source of the

future

so assuming that we can do the fusion

and we can create all of this heat how

do you get the heat out safely that’s a

really big problem

and our other machine down in south

orchard mass upgrade

is addressing this so uh matt so to put

this into some perspective

the heat that goes down on the surfaces

in one of our experiments

uh in present-day devices is about the

same heat

that you get at peak performance of a

diesel combustion engine

um working in a climate change field i

should be a bit

embarrassed to say that i drive a diesel

so i can be reasonably assured that that

is a safe

amount of heat to deal with in eta

and in future devices we expect it to go

up to a bit like a space shuttle

re-entering the atmosphere so

quite a quite an intense source of heat

but still something that we can manage

in a fusion reactor we expect it to be a

bit more like an arc welder

anyone done any welding if you have

you’ll know the arc welders are very

good at destroying things

so we do not want a fusion reactor

acting like an arc welder we need to do

something about this

and uh in this machine that you can see

here you’ll see that there are chambers

at the top

and chambers at the bottom of the device

now these are called the super x

diverter it’s a bit of a

fancy name but these are where we’re

diverting all of the excess heat that we

can no longer deal with

inside the plasma and what we’ve done

here is quite clever because we’ve

isolated

the part of the machine that we want to

keep cold

from the part of the machine that we

want to be really hot

so we’ve come up with a design that will

allow us to keep the hot stuff hot

and the cold stuff cold and this is

exactly what we want

if we’re going to operate one of these

things in the future now this is just a

concept at this stage and we’ll be

testing

out later this year if it works as we

expect then we think it should show um

that the concept works it’s a proof of

principle and then we can start looking

at upgrading this concept up designing

this concept

and integrating it into our designs for

future fusion reactors and this is

coming online later this year so look

out for headlines

and finally say we’ve solved this heat

issue and we’ve got burning plasmas

we’ve run our machine for about six

months it’s been all of the materials in

the machine have been exposed to the

most intense source

of high energy neutrons that the world

has ever known

you don’t want to go for a stroll in a

tokamak so

if you have to repair something like say

a pipe you have to do

you have to use robots and this little

animation shows you a robot

going along inside the pipe to a point

that we need to cut

once it gets to its location it’s going

to anchor itself in place

using some ball bearings on either side

and right at the center of the robot

there’s a little laser and in a second

you’ll see this laser rotate around

and it’s going to put a cut into that

pipe just where we need to repair it

now all of these things are operated by

humans but the humans are sitting

hundreds of meters away from these

robots in the nice safety uh in their

nice

armchairs up in a control room somewhere

and all of these things are done

remotely now you can imagine that when

you have to do things with robots even

simple jobs like

cutting a pipe become very very

non-trivial indeed

and we have lots of these jobs that need

to be done in a fusion reactor

once it’s come offline now this sounds a

bit like science fiction

but actually these things are designed

these things work and these things have

been tested and you can see here this is

a little robot

that we have down at the lab and these

are the two little bits of pipe that

it’s cut

so these things are we’re actually

thinking about these questions even

though they’re 40

30 20 years away at the moment we’re

thinking about these solutions right now

we have a center

down at our lab where we’re

investigating lots of these applications

with different robots

and to carry out these tasks that are

absolutely vital

for keeping our future fusion reactors

online

now hopefully i’ve done a good job of

convincing you that the future is fusion

fusion energy will be the energy source

of the future and it’s well worth all of

the time

money and dedication that we put into it

now but you don’t need to take my word

for it

why not listen to stephen hawking so

just before he died stephen hawking was

asked

what world-changing idea small or big

would you like to see implemented by

humanity

that is easy he said it’s not easy

i would like to see the development of

fusion power to give an unlimited supply

of clean energy

and um we’re getting there so

fusion power is still 20 years in the

future but hopefully i’ve shown you that

some of the exciting science we’re doing

right now is on the cusp of making

something like this

a reality a future fusion power plant

producing clean

safe abundant energy for our future

generations

thank you very much