From UPSC perspective, the following things are important :
Prelims level : Nuclear Fusion Reaction
Mains level : Cleaner energy resources
California based researchers have announced that their experiment has made a breakthrough in nuclear fusion research.
What exactly is Nuclear Fusion?
- Nuclear fusion is defined as the combining of several small nuclei into one large nucleus with the subsequent release of huge amounts of energy.
- The difference in mass between the reactants and products is manifested as either the release or the absorption of energy.
- Nuclear fusion powers our sun and harnessing this fusion energy could provide an unlimited amount of renewable energy.
- An example of nuclear fusion is the process of four hydrogens coming together to form helium.
What was the experiment?
- In the experiment, lasers were used to heat a small target or fuel pellets.
- These pellets containing deuterium and tritium fused and produced more energy.
- The team noted that they were able to achieve a yield of more than 1.3 megajoules of heat energy.
- This megajoule of energy released in the experiment is indeed impressive in fusion terms.
How was the new breakthrough achieved?
- The team used new diagnostics, improved laser precision, and even made changes to the design.
- They applied laser energy on fuel pellets to heat and pressurize them at conditions similar to that at the center of our Sun. This triggered the fusion reactions.
- These reactions released positively charged particles called alpha particles, which in turn heated the surrounding plasma.
- At high temperatures, electrons are ripped from an atom’s nuclei and become a plasma or an ionized state of matter. Plasma is also known as the fourth state of matter.
- The heated plasma also released alpha particles and a self-sustaining reaction called ignition took place.
Future prospects: Benefits
- It is expected that fusion could meet humanity’s energy needs for millions of years.
- Fusion fuel is plentiful and easily accessible: deuterium can be extracted inexpensively from seawater, and tritium can be produced from naturally abundant lithium.
- Future fusion reactors will not produce high activity, long-lived nuclear waste, and a meltdown at a fusion reactor is practically impossible.
- Importantly, nuclear fusion does not emit carbon dioxide or other greenhouse gases into the atmosphere, and so along with nuclear fission could play a future climate change mitigating role as a low carbon energy source.