Particles and antiparticles
Standard Model in Physics
As you know, any elementary particle has a number of characteristics, numbers that describe it. Among them are the following:
- Mass is a physical quantity that determines the gravitational interaction of an object.
- Spin is the intrinsic angular momentum of an elementary particle.
- Electric charge is a characteristic indicating the possibility of a body creating an electromagnetic field and participating in electromagnetic interaction.
- Color charge is an abstract concept that explains the interaction of quarks and their formation of other particles - hadrons.
Where did antimatter come from and where did it go?
Antimatter is closely related to the theme of the origin of the Universe as a result of the Big Bang about 14 billion years ago. This theory states that our entire Universe arose as a result of the explosion and expansion of a certain point in space. After the explosion, equal amounts of matter and antimatter emerged. The process of their mutual destruction immediately began. However, for some reason, there was a little more matter, which allowed the Universe to form in the form we are familiar with.
Now there is much less antimatter in the Universe than matter. Where did it go? If it flew away to another region of space, why is such an amount of antimatter not registered by anything? Antiparticles have the same mass as particles. If antimatter disappeared after annihilation with matter, then why is there so much “extra” matter left that makes up the world?
Maybe “inequality” arose earlier than people think? Or are antiparticles still not identical in properties to “their” particles and are more prone to decay? Antimatter can help solve these mysteries - not just predicted by formulas, but quite tangible by detectors.
Related materials
Also various other quantum numbers that determine the properties and states of particles. If we describe an antiparticle, then in simple terms it is a mirror image of a particle, with the same mass and electric charge. Why are scientists so interested in particles that are simply partly similar and partly different from their originals?
It turned out that the collision of a particle and an antiparticle leads to annihilation - their destruction, and the release of their corresponding energy in the form of other high-energy particles, that is, a small explosion. The study of antiparticles is also motivated by the fact that matter consisting of antiparticles (antimatter) is not independently formed in nature, according to the observations of scientists.
Cost of antimatter and its energy efficiency
Given the difficulty of obtaining and storing antimatter, it is not surprising that its price is very high. According to NASA calculations, in 2006, one milligram of positrons cost approximately $25 million. According to earlier data, a gram of antihydrogen was valued at $62 trillion. European physicists from CERN give approximately the same figures.
Potentially, antimatter is an ideal fuel, ultra-efficient and environmentally friendly. The problem is that all the antimatter that humans have created so far is barely enough to boil even a cup of coffee.
The synthesis of one gram of antimatter requires the expenditure of 25 million billion kilowatt-hours of energy, which makes any practical use of this substance simply absurd. Perhaps someday we will fuel starships with it, but for this we need to come up with simpler and cheaper methods of obtaining and long-term storage.
General information about antimatter
Coming from the above, it becomes clear that the observable Universe consists of matter, substance. However, following the known physical laws, scientists are confident that as a result of the Big Bang, matter and antimatter must be formed in equal quantities, which we do not observe. It is obvious that our understanding of the world is incomplete, and either scientists missed something in their calculations, or somewhere beyond our visibility, in distant parts of the Universe, there is a corresponding amount of antimatter, so to speak, “a world of antimatter.”
This question of antisymmetry appears to be one of the most famous unsolved problems in physics.
According to modern concepts, the structure of matter and antimatter is almost the same, for the reason that electromagnetic and strong interactions, which determine the structure of matter, act equally in relation to both particles and antiparticles. This fact was confirmed in November 2015 at the RHIC collider in the USA, when Russian and foreign scientists measured the strength of the interaction of antiprotons. It turned out to be equal to the force of interaction between protons.
Notes[edit | edit code]
- ↑Vlasov, 1966, p. 153.
- ↑ Fainberg, 2005.
- ↑ B. S. Ishkhanov, E. I. Kabin.
Physics of nuclei and particles, 20th century - Ch. “Antiparticles” // Nuclear physics on the Internet - ↑“Physicists have trapped antimatter atoms for the first time.”: ,
- ↑"Antihydrogen Trapped For 1000 Seconds": ,
- ↑New and Improved Antimatter Spaceship for Mars Missions. (2006). Access date: September 28, 2009. Archived August 22, 2011.
- ↑Reaching for the stars: Scientists examine using antimatter and fusion to propel future spacecraft. (12 April 1999). Access date: August 21, 2008. Archived August 22, 2011.
- ↑Questions & Answers. (2001). Access date: May 24, 2008. Archived August 22, 2011.
- ↑Shirokov, 1972, p. 345.
- ↑Physicists for the first time measured the force of interaction between antimatter particles
- ↑CERN specialists measured the optical spectrum of antimatter for the first time // RIA,
- ↑Scientists obtained the spectrum of antimatter for the first time //
- ↑ Zurab Silagadze
See the antistar // . - 2022. - No. 5. - ↑(English) (FAQ). (October 2004). - Questions and answers. Archived from the original on December 13, 2007.
Obtaining antimatter
Hydrogen and antihydrogen
The birth of antiparticles usually occurs when particle-antiparticle pairs are formed. If the collision of an electron and its antiparticle, a positron, releases two gamma quanta, then to create an electron-positron pair you will need a high-energy gamma quanta interacting with the electric field of the atomic nucleus. In laboratory conditions, this can happen at accelerators or in experiments with lasers. In natural conditions - in pulsars and near black holes, as well as during the interaction of cosmic rays with certain types of matter.
What is antimatter? For understanding, it is enough to give the following example. The simplest substance, the hydrogen atom, consists of one proton, which defines the nucleus, and an electron, which orbits around it. So antihydrogen is antimatter, the atom of which consists of an antiproton and a positron rotating around it.
General view of the ASACUSA installation at CERN, designed for the production and study of antihydrogen
Despite its simple formulation, antihydrogen synthesis is quite difficult. And yet, in 1995, at the LEAR accelerator at CERN, scientists managed to create 9 atoms of such antimatter, which lived for only 40 nanoseconds and decayed.
Later, using massive devices, a magnetic trap was created that held 38 antihydrogen atoms for 172 milliseconds (0.172 seconds), and after 170,000 antihydrogen atoms - 0.28 attograms (10-18 grams). This volume of antimatter may be sufficient for further study, and this is a success.
Receipt[edit | edit code]
In 1965, a group led by L. Lederman observed [ where?
] events of formation of antideuterium nuclei. In 1970, a group of scientists from the Institute of High Energy Physics (G.) recorded several events of nuclear formation.
In -1974, a group led by Yu. D. Prokoshkin at the Serpukhov accelerator also obtained heavier antinuclei - tritium (hydrogen isotope), helium (antihelium-3)
In 2001, the antihydrogen atom, consisting of a positron and an antiproton, was synthesized at CERN. In recent years, antihydrogen has been produced in significant quantities and a detailed study of its properties has begun.
In 2010, physicists for the first time managed to briefly “trap” antimatter atoms. To do this, scientists cooled a cloud containing about 30 thousand antiprotons to a temperature of 200 kelvins (minus 73.15 degrees Celsius), and a cloud of 2 million positrons to a temperature of 40 kelvins (minus 233.15 degrees Celsius). Physicists cooled antimatter in a Penning trap built inside the Ioffe-Pitchard trap. A total of 38 atoms were trapped and held for 172 milliseconds
In May 2011, the results of the previous experiment were significantly improved - this time 309 antiprotons were captured and held for 1000 seconds. Further experiments on confining antimatter are designed to show the presence or absence of an antigravity effect for antimatter
Cost[edit | edit code]
Antimatter is known to be the most expensive substance on Earth—a 2006 estimate estimated that a milligram of positrons cost approximately $25 million to produce. One gram of antihydrogen would cost $62.5 trillion, according to a 1999 estimate. CERN estimated in 2001 that producing a billionth of a gram of antimatter (the volume used by CERN in particle-antiparticle collisions over ten years) cost several hundred million Swiss francs
Application
The study of antimatter carries significant potential for humanity. The first and most interesting device theoretically powered by antimatter is the warp drive. Some may remember one from the famous TV series Star Trek, the engine was powered by a reactor that operated on the principle of annihilation of matter and antimatter.
Ship from the movie Star Trek
In fact, there are several mathematical models of such an engine, and according to their calculations, very few antiparticles will be needed for future spaceships. Thus, a seven-month flight to Mars can be reduced in duration to a month, due to 140 nanograms of antiprotons, which will act as a catalyst for nuclear fission in the ship's reactor. Thanks to such technologies, intergalactic flights can also be realized, which will allow humans to study other star systems in detail and colonize them in the future.
However, antimatter, like many other scientific discoveries, can pose a threat to humanity. As is known, the most terrible disaster, the atomic bombing of Hiroshima and Nagasaki, was carried out using two atomic bombs, the total mass of which is 8.6 tons and the power is about 35 kilotons. But when 1 kg of matter and 1 kg of antimatter collide, energy equal to 42,960 kilotons is released. The most powerful bomb ever developed by mankind, the AN602 or “Tsar Bomba,” released about 58,000 kilotons of energy, but weighed 26.5 tons! Summarizing all of the above, we can say with confidence that technologies and inventions based on antimatter can lead humanity to both an unprecedented breakthrough and complete self-destruction.
Existing and promising applications
Currently, antimatter is used in medicine, in positron emission tomography. This method allows you to obtain high-resolution images of human internal organs. Radioactive isotopes like potassium-40 are combined with organic substances like glucose and injected into the patient's bloodstream. There they emit positrons, which are annihilated when they encounter electrons in our body. The gamma radiation produced during this process forms an image of the organ or tissue being examined.
The antimatter is also being studied as a possible anti-cancer agent.
The use of antimatter undoubtedly has enormous prospects. It could lead to a real revolution in energy and allow people to reach the stars. A favorite hobby of the authors of science fiction novels are starships with so-called warp engines, which allow them to travel at superluminal speeds. Today, there are several mathematical models of such installations, and most of them use antimatter in their operation.
There are also more realistic proposals without superluminal flights and hyperspace. For example, it is proposed to throw a capsule of uranium-238 with deuterium and helium-3 inside into a cloud of antiprotons. The project developers believe that the interaction of these components will lead to the start of a thermonuclear reaction, the products of which, being directed by a magnetic field into the engine nozzle, will provide the ship with significant thrust.
For flights to Mars in one month, American engineers propose to use nuclear fission initiated by antiprotons. According to their calculations, only 140 nanograms of these particles are needed for such a journey.
Given the significant amount of energy released during the annihilation of antimatter, this substance is an excellent candidate for stuffing bombs and other explosive objects. Even a small amount of antimatter is enough to create a weapon comparable in power to a nuclear bomb. But for now it is premature to worry about this, because this technology is at the very early stages of its development. It is unlikely that such projects will be implemented in the coming decades.
In the meantime, antimatter is, first of all, a subject of study of theoretical science, which can tell a lot about the structure of our world. This state of affairs is unlikely to change until we learn how to obtain it on an industrial scale and reliably store it. Only then will it be possible to talk about the practical use of this substance.
