Nuclear Fusion…

At a laboratory in California, in what is called the National Ignition Facility, is the largest collection of giant lasers in the world. Their aim is to produce sustainable nuclear fusion similar to that happening in the Sun.

The nuclear power stations we currently have split large atoms (such as Uranium) in a process called nuclear fission. This releases energy in the form of heat that can be used to drive turbines and generate electricity. It also produces harmful radiation and leads to the production of nuclear waste that is very difficult to handle. It has to be stored in special facilities or buried deep underground to prevent the radiation it emits from harming the environment.

Nuclear fusion would not produce such harmful waste products because it combines small atoms to make larger ones. In theory it could provide a limitless source of energy on Earth. The difficulty is that incredibly high temperatures and pressures are needed to get the process started. The lasers at the NIF are capable of producing two million joules of ultra-violet light energy that can be focused on a fusion pellet. This raises its temperature to 3.3 million degrees Celsius causing it to implode and begin the fusion reactions. The pellet contains two isotopes of hydrogen (tritium and deuterium) which can then begin to join together to form helium. This reaction will produce more energy than it takes to focus the lasers in the first place.

The researchers have overcome many of the obstacles in their path and hope to ignite their first fusion reaction by the end of the year.

[ps As of July 2014 I have not heard that this has yet happened – perhaps you could find out for me. Thanks!]

Gosh this is an old article – and we still don’t have nuclear fusion. It would be great – essentially free electricity for the whole planet. A bit like data on your phone. You could pay a fixed fee and have as much you liked. That would be cool. Obviously they have encountered a few problems along the way so that no reaction has ever been sustained for more than a few fractions of a second. Now they are using AI to anticipate problems. You can read more about that here – it’s quite a meaty article despite the early reference to the Spice Girls.

Questions…

1. What is the nearest star to Earth?
2. What is the approximate speed of light through a vacuum (in m/s)?
3. What is an atom?
4. What is the Law of Conservation of Energy?
5. What transducer converts mechanical energy into electrical energy?
6. What is the unit of energy?
7. Ultra-violet light is higher frequency light than the visible spectrum. What form of light is just below the frequencies of visible light?
8. Helium is a noble gas. Can you name another?