IOP Schools Lecture 2010 – Part One

Taking in 35 venues across the UK, this year’s Institute of Physics Schools Lecturer, Dr Melanie Windridge, will explain to 13 000 students how scientists working on nuclear fusion hope to replicate the behaviour of the Sun here on Earth to produce a plentiful and environmentally friendly energy source.

Melanie, who has a PhD in plasma physics from Imperial College London, has appeared on BBC One’s Bang Goes the Theory and National Geographic Channel’s Mad Labs.  Having now designed her own interactive lecture for school children aged 14-16, she will be sharing her excitement for nuclear fusion with young live audiences.

While touring the country Melanie will be sharing regular blog posts with us, not just about her school lecture series but also about the physics behind fusion:

This year, 2010, I am the Schools and Colleges Lecturer for the Institute of Physics (IOP).  The IOP run an annual tour, with a lecturer visiting around 35 schools to deliver a talk on a particular aspect of physics.  This year that lucky lecturer is me, and I am going to be talking about “Powering the Future – the Physics behind Fusion”.  As I go along, I’m going to try and keep you updated about my movements around the country, and also give you a little, bite-size chunk of fusion info to take away with you.  (A bit like a virtual party-bag – your own little, napkin-wrapped slice of fusion cake….  Anyway…)

I arrived at my first stop, Crawley School, at 8.30am – one hour before my talk – to set up my various pieces of equipment.  Later, the children arrived in class groups and the lecture theatre was packed – there were even students sitting on the floor at the front.  According to the school we had about 240 people – a mixture of years 10, 11 and some sixth form.  I had ready volunteers to help with demonstrations, and lots of interesting questions at the end, including one boy asking what qualifications he would need to work in fusion, which was quite a satisfying end. 

So, onto your piece of fusion cake.  Since it’s day one, we’ll just have a think about what fusion is and why we need it.  And let’s first of all think about what the word “fusion” means – it means the joining together of two or more things to form a single entity. 

Nuclear fusion is the reaction that powers the Sun and stars, and we want to harness that power here on Earth as a new way of producing electricity.  Fusion as an energy source would solve the major world energy problems that are beginning to arise today.  We are in the middle of an energy crisis.  We have the problem of finite fossil fuels constantly nagging at us.  Even as energy companies search for more and employ ever-more-expensive extraction techniques we know that, one day, they will run out.  At the same time global population is increasing and industrialisation around the world means that our global energy needs are increasing every day. 

Then, of course, comes the issue of pollution.  Fossil fuels are unfavourable because they produce pollution, both of the smogs-and-smokes kind and of carbon dioxide, which contributes to climate change.  These are serious problems telling us to wind down our use of fossil fuels now.  It is clear that the world needs new ways to produce energy.
Now, we do have other energy options.  Renewable energy sources such as wind, solar and hydro-power will contribute to providing us with energy, but they have their own problems. 

One is that these sources are what’s known as “low energy density”, so one solar panel or one windmill doesn’t produce much energy.  You need a lot of them, and so they take up a lot of space.  To replace one fusion power plant you’d need about a thousand wind turbines, each with a blade diameter of about 100m.  The other problem is intermittency, so when the sun doesn’t shine or the wind doesn’t blow there is no energy.  I’m not saying that we shouldn’t use renewables at all – I think we need to use everything we can – but it’s questionable whether renewables will be able to satisfy our rising energy demands. 

If we were able to use fusion to generate electricity, it would go a long way towards solving all the world’s energy problems.  Fusion is the ideal energy source – it doesn’t take up much space, it has an almost inexhaustible supply of fuels, it is safe, it produces no carbon dioxide and no long-lived radioactive waste. 
Next time we’ll whizz through some basic atomic physics and the fusion reaction used in tokamaks, and I’ll be visiting Liverpool.