Fusion energy seems to be a technology with too much potential and promise, but when will it come to fruition?
People are always looking for cheaper and cleaner sources of energy, but the two concepts often do not go together. Fossil energy is cheap but polluting, renewable energy is expensive and inefficient, and nuclear energy has a radioactive risk.
Therefore, finding an inexhaustible source of low-cost energy has always been a man’s dream. We could have envisioned that dream with fusion or fusion technology , how the sun’s energy is generated, but the technology isn’t ready yet.
Fusion is the reaction that occurs in the core of the Sun, providing energy for the Earth for billions of years. (Image: Getty).
Inside the core of the Sun exists a “nuclear reactor” . Different from the principle of current nuclear reactors on Earth, which uses fission, a series of reactions that split uranium atoms to release energy; The process taking place in the core of the Sun is a fusion reaction that does the opposite of fusion of atoms together.
When two hydrogen nuclei fuse together to become helium, they create an enormous amount of energy. This process is called fusion or fusion. This reaction produces all of the energy, including the light and heat of the Sun.
Scientists will have to create an environment with extremely high temperatures and pressures, and have to control the output of energy generated from the reaction. (Photo: Xinhua).
If the reaction is capable of being carried out in a laboratory, it could provide virtually limitless base load electricity with near-zero carbon emissions. The easiest thing that can be done in the lab is the fusion of two different hydrogen isotopes: deuterium and tritium. The products of the reaction are helium ions and neutrons. Most previous fusion research has pursued this reaction.
The deuterium-tritium fusion reaction works most efficiently at temperatures of 100,000,000 degrees Celsius. Superconducting coils are used to create a magnetic field about 1 million times stronger than Earth’s in order to create out plasmas. The problem with current fusion experiments is that the energy required to create and maintain the reaction is far greater than the energy obtained.
The next phase of the research will involve an experiment called ITER that is being built in the south of France. At the ITER reactor, the heat generated from the reaction is equivalent to the temperature supplied for activation. In theory, this could create a source of excess energy. Previously, the most efficient fusion reactors produced only 67% of the energy delivered.
Several recently published studies suggest that researchers are looking for an alternative direction for fusion reactions. Theoretical physicist Heinrich Hora and colleagues at the University of New South Wales have patented a new technology that, instead of using hydrogen isotopes, combines hydrogen and boron atoms. Specifically, they will use a powerful laser to create a magnetic field and a second laser to heat hydrogen-boron fuel in order to reach the fusion ignition point.
When a hydrogen nucleus (a single proton) combines with a boron-11 nucleus, it produces three energetic helium nuclei. Compared to the deuterium-tritium reaction, this has the advantage of not producing any neutrons. Storing neutrons produced by fusion is still a challenge.
The challenge of the laser-triggered response is the accuracy and stability of the laser. (Photo: Lawrence Livermore National Laboratory).
However, the hydrogen-boron reaction is difficult to activate. Hora’s solution is to use a laser to heat a small fuel pellet to ignition temperature and another laser to heat a metal coil to create a magnetic field containing the plasma. They have to use very short laser pulses, just a few nanoseconds. The magnetic field of the hydrogen-boson reactor must be about 1,000 times that of the deuterium-tritium reaction.
Hora and colleagues claim that their process will create an “avalanche” effect in the fuel pellet, which means more different fusion reactions than expected. The team believes they can create a sustainable fusion reactor within the next five years. However, according to Science Alert, this forecast is somewhat optimistic.
Many organizations around the world have tried to complete this process. For example, the U.S. Energy Agency once tested using 192 laser beams to hit a small target that was close to reaching a triggering condition. However, they have not been able to precisely control the laser beam angle and beam stability. These are the variables that make the reaction incomplete.
If put into use, a power plant would have to perform laser irradiation 10 times per second. Meanwhile, the new trials reached a maximum frequency of 2 times/day.
For now, the best hope for reaching fusion energy remains the ITER project, a multinational collaborative effort. The reactor has a total cost of billion, and is currently about 65% complete. ITER will come into operation in 2025.