Antimatter:a Future Fuel

Dr. S. S. VERMA; Department of Physics, S.L.I.E.T., Longowal; Distt.-Sangrur (Punjab)-148 106

2017-09-27 07:47:37

Credit: centauri-dreams.org

Credit: centauri-dreams.org

Antimatter is nothing but regular matter with its fundamental charges reversed.  The existence of antimatter was first predicted in 1928. It's said to be a mirror image of matter. In regular or normal matter we have electrons protons and neutrons as the subatomic particles but in antimatter we have positron, antiproton and antineutron respectively.  Antimatter twin of electron called the positron, or antielectron was discovered in 1932.

The physical properties of both the particles and their antiparticles are same but their charges are reversed.  Antimatter is no more a fiction, it is real and its existence in this universe has been proved scientifically. It is even said that this universe is composed of more than 70% as antimatter and 30% as matter.  Antimatter can be used as a fuel because when matter comes in contact with antimatter, they both convert their total mass into energy and this energy can be used as a fuel. In a present energy driven civilization, fossil-fuels are running low and need of different energy sources is catching up. Solar, wind, nuclear and hydro power are all up there but they aren't as efficient as good old coal. It is thought presently that antimatter is a very plausible solution to the energy-crisis currently being experienced by our world. Today, antimatter is also being used in medical imaging systems for diagnoses but it could hold bigger promise in treating diseases. Chances are, antimatter will first be used as a medical treatment before it is used to travel to Mars. Scientists think it will be more effective than X-rays in killing cancerous tumors.

Energy potential

Antimatter, which exists on earth only as ephemeral particles created by giant accelerators, has long been considered a potentially ideal fuel for interstellar travel. When antimatter combines with ordinary matter, mutual annihilation occurs, with the release of vast amounts of energy, far greater even than that produced by thermonuclear fusion. The implosion of antimatter contacting matter can be collected and it's a great amount of energy. An antimatter implosion creates 100% energy which is beyond compare. However, only about 50% of it can be used by any technology made today due to neutrinos carrying away particles in reactions. This is still brilliant as nuclear energy is only about 7% efficient. This means that 1kg of matter reacting with 1kg of antimatter could create the equivalent energy of 47megatons of TNT (=2×1017 J). World annual energy demand is of the order of 500Btu ( 5.3x105J) and is expected to rise to 750 Btu (8x105J) by 2035, which means the energy produced with 1kg of antimatter and taking its 50% as useful can be enough to meet the energy demand of the world (@ of 8x105J demand) for 2.5x1011 years.  With this calculation even 1mg of antimatter will be enough to meet the energy demand of the whole world for next 1,25,000 years (which is also 125 years with 1μ gm of antimatter).

Developments so far

Scientists figure that most of the universe is made up of antimatter. When the universe was made matter and antimatter was made. Antimatter is made when two particles of matter are collided at incredibly high speeds. It can be made naturally in a high heat environment or artificially which has been done by scientists at CERN laboratory, France. This was done with a giant proton accelerator. It took many years but they have finally been able to make and store antimatter. Scientists make antiparticles by bombarding targets made of such elements as beryllium with ordinary particles shot from an accelerator. The collisions produce antiparticles, which can be gathered magnetically and channeled into "storage rings," where they are kept circulating in a vacuum, out of contact with ordinary matter, until needed.

Although the production of antiprotons and anti-electrons is now routine, it has proved difficult to force an anti-electron into an orbit around an antiproton, thereby creating an atom of antihydrogen. The difficulty is that these particles must be spawned from very high-energy collisions between normal particles, and the resulting antiparticles leave the collisions with very high energies themselves. The energies of these particles was usually about six billion electron-volts and  at such high energies, electrons simply refuse to fall into stable orbits around atomic nuclei and swiftly fly off. But scientists knew that if sufficient energy could be sapped from the particles before they were combined, they would remain together as stable atoms. Although the manufacture of antihydrogen will always be extremely expensive, it is now possible, at least in principle, to produce antihydrogen in substantial quantities. If used as a fuel, it could be stored in the form of antihydrogen ice. Scientists predict that an ice ball of antihydrogen at a temperature of only two degrees above the absolute zero held in a container made of ordinary matter at the same temperature would not explode.  Thus, the dream of driving a rocket to the stars on a pin-head quantity of antimatter fuel has come a step closer to reality with successful tests by scientists in Canada and Germany of a method for making antihydrogen. NASA scientists had announced early designs for an antimatter engine that could generate enormous thrust with only small amounts of antimatter fueling it. The amount of antimatter needed to supply the engine for a one-year trip to Mars could be as little as a millionth of a gram.

Bottlenecks of technology

One of the obstacles to creating a practical antimatter fuel has been the problem of converting subnuclear antimatter particles, which can be produced by accelerators, into real atoms of some anti-element, such as hydrogen. Although a scheme for doing so was proposed more than a decade ago, proof that it would work was lacking. In conclusion, antimatter will more than likely be one of the main power sources used in the future if some of the major concerns about it and its use are overcome. First is its cost of generation as it costs $62.5 trillion to create any amount of antimatter, and it is only made in small amounts for safety. Another reason it isn't made as a fuel is that if a large amount was to go to a corrupt government for instance, many of the dominant countries could be attacked in a giant war of the governments. If there was a way to safely distribute antimatter without fear of being killed in an implosion then it would be easily used to overcome emerging energy crisis. Further, how the use of antimatter will affect our lives is yet unknown.