Historic moment unfolded after successful launch of nuclear fusion

Human intelligence has reached a crucial milestone towards finding a miraculous solution for the world's two major problems global warming and scarcity of energy. A historic moment unfolded after the successful launch of Nuclear Fusion on the planet, which provides light to the stars. It was made possible by decades of efforts put in by scientists.

Hyderabad: Human intelligence has reached a crucial milestone towards finding a miraculous solution for the two major problems faced by the world, global warming and scarcity of energy. A historic moment unfolded after the successful launch of nuclear fusion on the planet, which provides light to the stars. It was made possible by decades of efforts put in by scientists.

What is nuclear fusion? The Sun and other stars release energy through nuclear fusion. The light hydrogen atoms combine to form the heavy element helium and immense energy is released in the form of light and heat in this process. This is the source of solar light and heat.

• But it is very difficult to combine two identical atoms because they have the same charge, and as two charged edges in batteries repel each other, these also do not meet. The atoms only meet under unusual circumstances.
• Fusion is possible in the sun's core due to the huge temperature levels (millions of degrees Celsius) and pressure (100 billion times greater than Earth's atmosphere). Due to Sun's extraordinary gravitational force, such conditions are created naturally.
• Fusion processes take place in extremely hot plasma. It contains charged ions and freely moving electrons and its properties are different from solid, liquid and gas.

The current progress: Researchers at the National Ignition Facility (NIF) of the Lawrence Livermore National Lab in California, USA, achieved a key milestone called 'Fusion Ignition' on December 5, 2022. The production of more energy expended in the fusion process is called 'Fusion Ignition'.

In NIF, a small amount of fuel containing Deuterium and Tritium is placed in a capsule. In all, 192 lasers are used for this and their beams can heat up to 10 million degrees Celsius and exert pressure 100 billion times greater than the earth's atmosphere.

• X-rays are produced when the laser beams hit the capsule. They subject the fuel to temperatures of millions of degrees Celsius and extreme pressure. As a result, the conditions that exist in a star for a short period have been discovered.
• After this experiment, the scientists examined the ratio of the energy released in the fusion process and the energy used by the lasers. This is called 'Gain'. If it is greater than 1, more energy is released in the fusion process than is consumed by the lasers.
• Lasers with an energy of 20 lakh Joules were applied to the fuel in NIF. All this happened in a billionth of a second. As a result, 30 lakh joules of energy were released. That is, the gain is 1.5. Thus, there has never been a record of more energy produced than consumed before this.
• In the NIF experiment, less fuel than a pea seed was used. The energy generated by this is sufficient to heat 15-20 kettles used for brewing tea.

The 'Fusion Process' is different from 'Nuclear Fission Reactors' currently used to generate electricity.

• Atoms are broken in Nuclear Fission Reactors. Hazardous radioactive materials are released in this process. They have to be stored in a safe place for hundreds of years.
• The waste produced in Fusion Process is less radioactive and deteriorates quickly. Fossil fuels like oil and gas, which are responsible for greenhouse emissions, are not used in the Fusion Process, which emits Helium, a non-poisonous inert gas.
• It is difficult to initiate and sustain Nuclear Fusion, therefore it is unlikely to get out of control. The process includes a 'Self-Regulatory Mechanism', where if the operators are unable to control the action, the machine switches it off. Once the action stops, the plasma loses its energy very quickly, shutting down the reactor before any damage is done to it.

Since the 1950s, scientists from more than 50 countries have been trying to study the Fusion Process that takes place on stars. According to them, this can generate massive amounts of environment-friendly electricity. However, there is not as much gravitational force on the earth as it is on the Sun. Therefore, to create fusion here, a temperature higher than that of the Sun is required.

Mainly scientists use Hydrogen Isotopes like Deuterium and Tritium as fuel in fusion. For these two to meet, a temperature of 10 million degrees Celsius and extreme pressure are required. The plasma produced by fusion must control the magnetic forces. It is also difficult to sustain this activity for long and scientists are trying to overcome these difficulties one by one.

Benefits of Nuclear Fusion:

• Unlike solar and wind energy, fusion does not depend on favourable weather conditions. By widely using this approach, countries can achieve 'Net Zero Emission Levels' by 2050.
• Fusion can produce four times more energy per kilogram of fuel as compared to Nuclear Fission, and 40 lakh times more energy can be achieved simultaneously by using it, compared to oil or coal.
• Fuels used in Fusion Processes are abundant on Earth. Deuterium can be produced cheaply from seawater and Tritium can be shed by Lithium for the Fusion Process. Lithium reserves are plentiful and with these, we can meet our energy needs for millions of years.

A TeraJoule of energy can be produced with just a few grams of fuel (Deuterium, Tritium) in a Fusion Reaction. This is enough to meet the energy needs of a person in a developed country for 60 years. Every second, 60 crore tonnes of Hydrogen are converted into Helium by Fusion on the Sun. It takes 30 thousand years for the particle of light produced in this process to come out of the Sun.

Places for Improvement:

• Analysts say it will still take at least 30 years for Fusion to become a viable energy source that can power our homes constantly. There are many technical challenges yet to be overcome in this process.
• Although the construction of NIF was completed in 2009, it produced 10 lakh joules of energy initially. Today it has increased to 20 lakh joules. In this way, more powerful and efficient lasers will make good progress.
• Sustaining Fusion conditions for long periods is a challenging affair. If there is any difference in the fuel capsule, the power produced by this tool will be reduced compared to the electricity used. Scientists have made progress in efficiently delivering lasers, and then X-ray radioactivity, to the fuel capsule. However, currently, only 10 to 30 per cent of the total laser energy is delivered from the capsule to the fuel.
• A lot of effort is needed in understanding the whole system, not just the lasers and the fuel. Not much research has been done on Fusion Reactors, which use Neutrons produced in Fusion Processes to drive steam turbines and generate electricity.