1. Nuclear Fusion: Using the energy of the stars on Earth

2. The Principle

3. Collision: Deuterium and Tritium

4. How is it made?  In Stars: The gravity pressure makes the atoms close enough for the fusion. The high temperatures keep the plasma state making the collisions easier.  On Earth: The super gravity of the stars can’t be reproduced, so the temperature must be risen a lot, about ten times the sun’s center. The atoms will move so fast the collision and fusion will happen.

5. The Process  Exactly the opposite of the conventional fission energy, with some advantages over it: the radioactive nuclear waste has low intensity and vanish in a few years, beyond that, there’s no risk of disasters  As the fission, represents no harm for the nature

6. Why it’s not used?  No nuclear reactor until now has made it to produce more energy than the needed for its running.  The first prototype with chance to achieve this goal is the ITER (International Thermonuclear Experimental Reactor) which is being build in France since last year.

7. Difficulties - ITER  The difficulties start with the lack of tritium on earth, it’s estimated that there are only 20 Kg of this isotope.  The solution found was put the machine itself to produce it, they will try to use lithium, once when the energized neutron hits it, tritium is liberated.

8. ITER - Temperature  Three systems will be used to reach the required temperature:  First neutral particles are injected in high speed  The second will emit radio waves in different frequencies,similar to micro-waves ovens  And the third will use a beam of eletromagnetic radiation to make hot the electrons inside the machine.

9. Keeping the temperature  However, none of this will work if the plasma touch the internal structure of the machine. The trade of heat between the wall and the hydrogen would cold the last one, stopping the whole process  That’s why it represents no risk, if anything fails the machine turns off.

10. ITER  The reactor model to avoid this contact used in ITER is called ‘tokamak’.It’s used nowadays in JET, the reactor that was used as a base for ITER’s project.  It has the shape of a tyre, with vacuum and a strong magnetic field, 200 000 times the earth’s one.  This will keep the plasma far from the structure walls

11. ITER’s Scheme

12. Alternatives of fusion  In USA we have two inertial fusion reactors:  The laser beams, where 192 laser beams hit a small ball the size of a pea, fusing the atoms inside.  Electrical chock used in the Z machine: electrical discharges of high power to make the fusion

13. Alternatives of fusion  And the Stellarators, in Japan, who works as the tokamaks, the difference is in the spiral shape which distributes better the magnetic field.

14. Future  ITER will be ready in 8 years time, it’s expected to produce ten times more energy than it consumes.  If it succed,the project of Demo, the first fusion reactor with commercial goals, will start, it’s predicted to be operating in 2040.