 |
|
|
|
|
|
|
Nuclear Fusion and Nuclear Fission are two very different forms of energy and it is important to not confuse the two. Nuclear Fission is a splitting of atoms, while nuclear fusion is the fusing, or joining of atoms. Fusion is the oldest form of energy generation, being used in the original source of energy, the sun. The incredible temperature of 15,000,000 degrees Celsius (27,000,000 degrees Fahrenheit) in the core of stars allows the fusing of hydrogen atoms and the release energy in the form of heat and light. This energy radiates down on the earth and is the source of almost all other energy reserves, from oil to coal and even wind.
|
|
|
|
The first fusion experiment on earth was carried out in the early 1930’s. The experiment involved deuterium, the isotope of hydrogen with a mass of two. The Deuterium was placed in a particle accelerator and was bombarded with an accelerated beam of deuterium. The colliding of the two atoms caused them to fuse together and release energy. Although energy was released by the experiment, so much energy was required to create the beam of accelerated deuterium that no useful energy was produced.
The next experiment with fusion was in the 1950’s, and is most often associated with the nuclear age. The hydrogen bomb was created and used fusion to release immense amounts of energy in an uncontrolled, deadly explosion. This method of fusion releases more energy than is put into it, but the extra energy is released so quickly and uncontrollably that it is not useful for electrical generation. For fusion to be useful, a slow, controlled reaction is required.
|
|
|
|
To create a useful fusion reaction, two atomic nuclei must be fused into one. In order for this to happen, immense temperatures must be applied so the natural repulsion between two atoms is succumbed. This repulsion is called Coulomb repulsion. The surrounding gas must be heated to 50 to 100 million degrees centigrade, (90 to 180 million degrees Fahrenheit) before the repulsion is neutralized. Once this temperature is reached, fusion occurs and creates its own heat. This point in the reaction is called Nuclear Ignition and it is at this point that the reaction is self-sustaining, so long as sufficient hydrogen atoms are present to be fused.
The point when a grouping of hydrogen atoms with positive and negative charges reaches 100,000 degrees Celsius (180,000 degrees Fahrenheit) is called Plasma. The plasma contains the heat energy required for the fusion reaction, but it cannot be contained due to the fact that it is so hot, and cools so fast. Many methods of containing plasma have been devised, but the most promising invention is containing plasma in a magnetic force field. In the field, the plasma touches nothing, and therefore, stays hot and doesn’t burn through a container.
|
|
|
|
The problems faced with nuclear fusion are essentially the energy put into the reaction is more than that which is released by the reaction. For a reaction to be successful, more energy must be released than is put into the heating of the plasma. The Lawson criterion states that when time (t) and plasma density (n) exceed 1014, the reaction produces more output than input and is generating electricity. tn >1014
|
|
|
|
Recently, another method of fusion has been explored using completely different techniques. A fuel, such as Tritium or Deuterium is contained in a tiny pellet. This pellet is bombarded on several sides with a pulsating laser beam, which causes the pellet to implode. The implosion of the pellet and the thermonuclear reaction ignite the nuclear reaction. This method is being tested in the United States and elsewhere in the world.
Most recently, success with fusion reactions has grown as the technology required to create successful reactions grows. 1.7 million watts were produced from a controlled reaction at the Joint European Torus (JET) in England, and most recently, in 1993, Princeton had an output on 5.6 million watts. Unfortunately, both of these reactions consumed more energy than they released.
|
|
|
|
When we do discover how to utilize nuclear fusion, we will have tapped into a safe and unlimited resource of energy. Research in this field must continue for us to find a way. We may not be too far away from a fusion reaction that obeys the Lawson Criterion, but you must continue to search and innovate to make this limitless power source a success!
|
|
|
|
 Victor Campos from Chile contributed:
I would like to help you with the translations. I am not an expert or something like that but if you like I can correct or modify what you have to give sense on your texts like this:
Albert Einstein nació en Ulm, Alemania la 14 de marzo de 1879. Cinco años más tarde, en 1884, él y su familia se trasladaron a Munich debido al nuevo trabajo de su padre. En 1901 lo naturalizaban como ciudadano suizo. Ocho años más tarde cuando Einstein era suizo a el le agradó el trabajo de su profesor de física teórica en la universidad de Zurich. A partir la 1911 a 1912 él tenía el mismo trabajo que un profesor en Praga. En 1913 lo eligieron para formar parte de la academia de ciencia en Berlín. Einstein recibió el reconocimiento de su pais natal Alemania obteniendo así la nacionalidad alemana en 1914. Él trabajó por 19 años como profesor en Berlín. A partir la 1920 a 1946 Él podía - oficialmente - ser profesor especial en Leiden, Holanda, también, pero debido a su emigración, él no trabajó para la universidad durante mucho tiempo antes de 1946. Debido al movimiento NAZI, Einstein renunció la ciudadanía alemana en 1933. Él se trasladó a los Estados Unidos y trabajó como profesor en Princeton, New Jersey hasta 1945. Él se hizo oficialmente americano en 1941. Albert Einstein murió el 18 de abril de 1955.
VCC
|
|
Kirit M from India contributed:
to fuse two nuclei why don't we use the property that two similar charges moving in the same direction attract each other.
|
|
|
|
|
|
|
|
 | Take control over your own nuc... more
Copyright © 1995 Linköping University, Linköping, Sweden. Permission obtained on 11th of August, by Email message. |
 | The nuclear building of a powe... more
Copyright © EPZ. Permission obtained on 10th of August, by Telephone. |
 | This image shows how a nuclear... more
Copyright © EPZ. Permission obtained on 10th of August, by Telephone. |
| A power plant with the cooling... more
Copyright © EPZ. Permission obtained on 10th of August, by Telephone. |
|
|
