To know what is nuclear fusion

Grade C

To describe nuclear fusion

Grade B

To be able explain where the Sun’s energy

comes fromGrade A

Nuclear Fusion

So far we have studied Nuclear Fission – where atoms were split to release energy.

Nuclear Fusion – is the joining of atoms to make heavier ones.

To know what is nuclear fusion

Grade C

To describe nuclear fusionGrade B

To be able explain where the Sun’s energy comes

fromGrade A

Nuclear Fusion

Could a glass of water provide the same amount of energy as a tanker of petrol?

To know what is nuclear fusion

Grade C

To describe nuclear fusionGrade B

To be able explain where the Sun’s energy comes

fromGrade A

Fusion

The Sun releases energy by fusion

The Sun is made up of 75% Hydrogen and 25% Helium

The Core is so hot – it consists of Plasma of bare nuclei with no electrons.

In the 100 000 000oC plasma of a fusion reactor the protons and neutrons are separate and whiz about

Fusion

H + H H + p1 1 2 0

1 1 1 1

Protons join together releasing energy

The nuclear reaction turns a proton into a neutron

The reaction forms ‘Heavy Hydrogen’.

Fusion

Another proton binds

Fusion

H + H He2 1 31 1 2

Two heavier nuclei collide – form helium nucleus

Fusion

He + He He + p + p 3 3 4 1 12 2 2 1 1

Fusion

Summary

= neutron

= proton

H2

1

H1

1

He3

2

He4

2

The Energy at each stage is carried away as Kinetic

Energy.

Nuclear Fusion

Could a glass of water provide the same amount of energy as a tanker of petrol?

To know what is nuclear fusion

Grade C

To describe nuclear fusionGrade B

To be able explain where the Sun’s energy comes

fromGrade A

Yes – if we could make a fusion reactor here on Earth

Nuclear Fusion Reactor

Problems:

-The Plasma of light nuclei must be heated to very high temperatures (this is because you need to overcome

the repulsion of two positive nuclei).

To know what is nuclear fusion

Grade C

To describe nuclear fusionGrade B

To be able explain where the Sun’s energy comes

fromGrade A

Nuclear Fusion Reactor

Solutions:

-Heated – via electrical currents-Contained using a magnetic field – so doesn’t touch

the walls of the reactor.

To know what is nuclear fusion

Grade C

To describe nuclear fusionGrade B

To be able explain where the Sun’s energy comes

fromGrade A

1.Describe carefully what happens to a nucleus during fusion.

2.Why does the plasma need to be hot? How is it contained?

3.Extension; Do you think nuclear fusion is a good source of energy. Evaluate the pros and cons.

4.Rebecca bonus; Do you think governments are right to spend money on purely scientific research e.g. space missions? Explain

Are you now able to….

I still feel unsure. I need some more help to understand.

I feel ok. I need to do some more work to check my understanding.

I am happy and feel I understand and can explain the main points.

To know what is nuclear fusion

Grade C

To describe nuclear fusion

Grade B

To be able explain where the Sun’s energy

comes fromGrade A