Friday, November 16, 2012

What does nuclear fusion mean for our energy future?

Nuclear fusion is very common process that occurs naturally and regularly in stars, including our own Sun. The scientists have already managed to achieve artificial nuclear fusion though they still need to find the methods that would enable them to maintain the full control over the entire process of nuclear fusion. 

Nuclear fusion reaction needs to be controlled all the time because if we let nuclear fusion reaction occurring as an uncontrolled chain reaction, it can even result in a huge thermonuclear blast (for instance nuclear fusion for military purposes began with the research in the early 1940s as part of the Manhattan Project-making of the atomic bomb). 

What this means is that only controlled nuclear fusion can be considered as the safe source of energy. The scientific research into controlled fusion, mostly with the purpose to produce fusion power for the production of electricity, has been conducted for more than 50 years. Despite the evident progress and some notable experiments scientists still aren't able to totally control this process.

The energy that originates from nuclear fusion has kept our Sun burning and shining for billions of years. The process of nuclear fusion that happens naturally in the stars like our Sun is the result of interaction between the nuclei of lighter elements (such as hydrogen) in which they get fused together at extremely high temperatures and pressures to form heavier elements (such as helium).

Our Sun wouldn't shine without the nuclear fusion

Nuclear fusion is almost limitless source of energy so it's no wonder that scientists from all over the globe study it, driven primarily by the idea that nuclear fusion can lead to carbon-free energy future. In order to create nuclear fusion process in the laboratory scientists require extremely high temperatures (hydrogen isotopes for instance are usually heated to temperatures of over 10 million degrees Celsius.) The higher the temperature, the faster the atoms or nuclei move. The fuel used for a fusion reactor is usually deuterium. Deuterium can be obtained by extraction from ordinary water.

The main purpose of the nuclear fusion that occurs in the laboratory is the creation of an ionized gas called plasma. The resulting plasma (very hot, ionized gas that can conduct electricity is basically a stuff all stars were made of) needs to become sufficiently hot and dense in order to produce large quantities of high-energy helium ions (alpha particles).

Many scientists are still convinced that nuclear fusion will become the key energy source in future. Nuclear fusion releases an enormous amount of energy, in average close to one million times that of a chemical reaction. It has been said that the advanced research and development in fusion energy could also lead to major progress in high speed computing, high power lasers, electronic diagnostic equipment, etc.

Nuclear fusion is in constant need of large amount of energy because nuclei strongly resist being put too close together, even for the lightest elements such as hydrogen. The good side is that nuclear fusion usually releases lot more energy than it takes to join nuclei together.

The theory of cold fusion has also been very popular lately, and it refers to fusion at low enough temperatures to make profits, meaning that the output energy would be far greater than input energy.