Atoms & Fusion • An atom is the smallest unit of a particular substance that you can have; one of the tiniest particles of any material or element. • There are 2 million atoms across the head of a pin. • Fusion is a nuclear reaction in which nuclei (the central part of an atom) combine to form more massive nuclei with the simultaneous release of energy. How do we explain this to children? Fusion is when two things stick together and give off energy. The Sun & Space • There are 125 billion stars in the Milky Way. • The surface of the Sun is 5000°C. • The core of the Sun is 15 million°C. • Sunspots are cooler than the rest of the surface, because of the intense magnetic activity in them. • Sunspots can affect our communication systems here on Earth (like TV, radios etc) because of the high magnetic activity. • Solar flares are big eruptions of hot gas on the surface of the Sun and are often associated with sunspots. • Solar flares throw particles of dust into space and when they hit the Earth’s magnetic field some get trapped in it and produce an amazing light show – the Aurora borealis or Northern Lights in the Northern Hemisphere (and Aurora australis or Southern Lights in the Southern Hemisphere). • Fusion occurs in the core of the Sun. Hydrogen atoms fuse and form helium while releasing energy. • You could fit one million Earths in the Sun. • The Earth is 93 million miles away from the Sun. • The satellite SOHO, which is observing the Sun for us, is 1 million miles away from Earth. Fusion Research At the Culham Centre for Fusion Energy, scientists are trying to make the sun – by recreating the process of fusion – and develop a new way of generating electricity. • The Culham Centre for Fusion Energy runs 2 devices to recreate fusion – fusion machines – MAST and JET. • The sun inside the smaller fusion machine MAST is 15 million°C. • The sun inside JET is 150-200 million°C. • The inside of the fusion machines is dough-nut shaped. • The amount of fuel we put inside our fusion machines weighs the same as a postage stamp. • ITER is a new fusion machine being built in Cadarache, South of France, and it is the result of an international partnership between the EU, USA, Japan, South Korea, China, India and Russia. • ITER will take 8-10 years to finish and it will be twice as big as JET. • ITER will produce 10 times more power out from fusion than we put into it.

The Sun Dome was funded directly by public engagement funds from the UK Engineering and Physical Sciences Research Council (EPSRC) and EURATOM