Antimatter
Everything is made up of matter which is constituted by one or more elements in its structure. To a layperson, matter is anything that has mass and occupies space.
Antimatter is a matter that is composed of the antiparticles of the corresponding particles of ordinary matter.
For example, Hydrogen as an atom is composed of one proton orbited by a single electron. The proton and electron are the particles and their antiparticles are antiproton and positron respectively. The antiproton and positron can also form an antiHydrogen atom.
So, basically antimatter is composed of the opposite of the normal matter.
Theoretically, a proton is positively charged so, its antiparticle will be negatively charged. There are other differences too such as in their quantum numbers, but they have the same mass. Even the chargeless neutron has an antiparticle, antineutron. A neutron is composed of quarks that are charged; the antineutron is also composed of antiquarks.
Scientists study naturally occurring antimatter by studying the cosmic radiation that rains down upon the earth, thunder clouds, beta decays of some radioactive matters. However, these phenomena are not suitable for proper experimentations.
Instead of observing antimatter produced via nature, scientists study it by producing it themselves - through a particle accelerator. When ordinary particles are accelerated at a very high velocity, they collide with each other; antiparticles can be borne out of the ensuing high-energy collision.
Unfortunately, these antiparticles are short-lived and invariably meet their corresponding ordinary matter in a destructive process called annihilation. Annihilation doesn't mean that the particles completely disappear, it just means that their energy is transferred to a different form. The released energy is usually proportional to the total mass of the collided matter and antimatter, in accordance with the Albert Einstein's famous equation, E = mc2; the energy when harnessed can be of great use.
According to the European Organization for Nuclear Research, CERN
- If you have a gram of antimatter, you could drive your car for about 100,000 years!
- The annihilation of 1kg of antimatter can result in a reaction equivalent to 43 megatons of TNT – slightly less than the yield of the 27,000 kg Tsar Bomba, the largest thermonuclear weapon ever detonated.
Antimatter holds the key to a lot of technological advancement, but the problem lies in the efficiency and extreme cost of its production and storage.
NASA estimated that it will cost about $62.5 trillion to produce one gram of antihydrogen.
To study antimatter, it needs to be prevented from annihilating with matter.
Antimatter in the form of charged particles (such as positrons and antiprotons) can be contained by a combination of electric and magnetic fields, in a device called a Penning trap. The penning trap is comparable to tiny accelerators. Inside, particles spiral around as the magnetic and electric fields to keep them from colliding with the walls of the trap.Producing antimatter is different from storing it. After production, scientists might get to store only 0.1% of the initial value and only nanograms of it have been stored so far.
If all the antimatter ever made by humans were annihilated at once, the energy produced wouldn’t even be enough to boil a cup of tea.
Antimatter is routinely used in medicine, Positron emission tomography (PET). PET is a nuclear medicine imaging technique that can be used to diagnose and determine the severity of or treat a variety of diseases, including cancers, heart disease, gastrointestinal, neurological disorders and other abnormalities within the body. In PET scans, a small amount of radioactive substance is injected into a person, which produces positrons upon decaying within the body. By detecting the high-energy photons (gamma rays) produced in the annihilation of positrons with electrons in the body, a map can be made of where the substance has spread within the body.
References:
- http://www.iop.org/resources/topic/archive/antimatter/index.html
- https://phys.org/news/2005-09-antimatter.amp
- https://en.m.wikipedia.org/wiki/Antimatter
- https://www.symmetrymagazine.org/article/april-2015/ten-things-you-might-not-know-about-antimatter
- https://www.zdnet.com/article/the-practical-uses-of-antimatter/
- http://www.scienzagiovane.unibo.it/English/antimatter/7-antimatter-faq.html