Controlled nuclear fission have been carried out before fission bombs
were built. Soon after the detonation of atomic bombs, fission reactors
have been designed, built, and applied to generate power.
In contrast, the first fusion bomb exploded
Enewetak atoll on Nov. 1, 1952,
but controlled fusion for power generation has not been realized yet.
In parallel with the development of the hydrogen bomb, massive efforts
towards achieving controlled thermonuclear fusion (CTF) were initiated
in a number of countries. The most promising reaction is
D + T ® 4He + n + 17.6 MeV.
This reaction releases a large amount of energy, and has the lowest ignition
temperature, 40,000,000 K.
Basic requirements for CTF of the above reaction are to:
To date, it is still a challenge to produce more energy than the energy
used to heat the plasma and maintain a steady fusion rate.
- achieve a temperature of 100,000,000 K,
- confine a large number of nuclei in the plasma in a small volume for a
length of time,
- sustain the fusion
- extract energy from the products after fusion.
Magnetic confinement and inertia confinement are well known
techniques to maintain a large number of nuclei in a small volume for a
long period of time.