Environmental Engineering Reference
In-Depth Information
Scientists have managed to reproduce hydrogen fusion on Earth, but not in a reactor. In
1952, the first hydrogen bomb was exploded on the Enewetak Atoll in the Pacific Ocean,
releasing 450 times the energy of the fission-based bomb that was unleashed over Nagasaki
seven years earlier. Releasing such a massive burst of energy is one thing; harnessing it to
produce electrical power is another.
The greatest challenge with hydrogen fusion is getting the reaction started. Because the
nuclei of hydrogen atoms are positively charged, they repel one another like the equivalent
poles of magnets. To bring about fusion, it is therefore necessary to slam hydrogen
atoms into one another with great force. The hydrogen bomb gains this initial burst of
energy from a small fission-based atomic bomb within the missile shell. Thus, fission
ignites fusion. Temperatures of 100 million degrees Celsius would be needed to initiate an
industrial-scale fusion reaction. No known material can withstand such temperatures, and
without a container the reaction cannot be controlled.
This limitation has not prevented scientists from experimenting with fusion in the
laboratory. Two main fusion experiments are currently underway: the National Ignition
Facility (NIF) in the United States and the International Thermonuclear Experimental
Reactor (ITER) in France. The first uses 190 concentrated laser beams to heat a small
amount of hydrogen fuel to the point where the atoms fuse. The second is a circular
magnetic chamber that compresses atoms to achieve fusion and prevent the reactor wall
from melting.
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