In the field of nuclear physics, the different types of radiation that exist are studied. In this case, we will focus on gamma rays . These are electromagnetic radiations produced by the radioactive decay of atomic nuclei. Gamma rays have the highest frequency and are among the most dangerous to humans, as are other ionizing radiations. This is because, although they have no electrical charge, they can cause significant damage to human cells and their DNA.
Therefore, we're going to dedicate this article to telling you about the characteristics, importance, and uses of gamma rays. We'll also discuss their implications for health and applications in advanced technologies, such as medicine.
Key features
In summary, we are going to list the main characteristics of gamma rays:
- They are particles that have no more at rest since they move at the speed of light.
- They also have no electrical charge since they are not deflected by electric and magnetic fields.
- They have very little ionizing power although they are quite penetrating. Gamma rays of radon they can go through up to 15 cm of steel.
- They are waves like light but much more energetic than X-rays.
- A radioactive compound that is absorbed in a gland and avoids gamma radiation makes it possible to study said gland by obtaining it on a beach.
Gamma rays are very high-frequency radiation and are among the most dangerous types of radiation for humans, as are all ionizing radiations. The danger lies in the fact that they are high-energy waves that can irreversibly damage the molecules that make up cells, causing genetic mutations and even death. On Earth, we can observe natural sources of gamma rays in the decay of radionuclides and the interaction of cosmic rays with the atmosphere; very few lightning strikes also produce this type of radiation. Furthermore, if you wish to learn more about other types of radiation, you can consult our article on everything you need to know about lightning.
Gamma ray properties
Normally, the frequency of this radiation is greater than 1020 Hz, so it has an energy greater than 100 keV and a wavelength less than 3 × 10 -13 m, much less than the diameter of an atom. Interactions involving gamma rays of energy from TeV to PeV have also been studied.
Gamma rays are more penetrating than radiation produced by other forms of radioactive decay, or alpha decay and beta decay, due to the lesser tendency to interact with matter. Gamma radiation is made up of photons. This is a substantial difference from alpha radiation which is made up of helium nuclei and beta radiation which is made up of electrons.
Photons, being massless, are less ionizing. At these frequencies, the description of the interactions between the electromagnetic field and matter cannot ignore quantum mechanics. Gamma rays are distinguished from X-rays by their origin. They are produced by nuclear or subatomic transitions, while X-rays are produced by energy transitions due to electrons moving from external quantized energy levels to higher internal free energy levels.
Since some electronic transitions can exceed the energy of some nuclear transitions, the frequency of higher-energy X-rays can be higher than the frequency of lower-energy gamma rays. But in fact, they are all electromagnetic waves, like radio waves and light. If you'd like to learn more about other components of the spectrum, you can check out our article on spectroscopy: types and characteristics.
Materials made thanks to gamma rays
The material required to shield against gamma rays is much thicker than that required to shield against alpha and beta particles. These materials can be blocked with a simple sheet of paper (α) or a thin metal plate (β). Materials with high atomic number and high density absorb gamma rays more effectively. In fact, if 1 cm of lead is required to reduce the intensity of gamma rays by 50%, the same effect occurs with 6 cm of cement and 9 cm of packed earth.
Shielding materials are generally measured in terms of the thickness needed to cut the radiation intensity in half. Obviously, the higher the energy of the photon, the greater the thickness of the required shield.
Therefore, thick shielding is needed to protect humans, because gamma rays and X-rays can cause burns, cancer, and genetic mutations. For example, in nuclear power plants, it is used to shield the steel and cement in pellet containment, while water can prevent radiation during fuel rod storage or during reactor core transport. If you want to learn more about how light works in the context of radiation, check out our article on what light is.
Uses
Ionizing radiation treatment is a physical method used to achieve the sterilization of medical and sanitary materials, the decontamination of food, raw materials and industrial products, and its application in other fields , we will see later.
This process involves exposing the final packaged or bulk product or substance to ionizing energy. This is done in a special room called an irradiation room for each specific situation and within a specific period of time. These waves completely penetrate exposed products, including multilayer packaged products.
The use of Cobalt-60 for the treatment of tumors is a method that is currently widespread in my country and around the world due to its efficacy and inherent safety. It is called cobalt therapy and involves exposing the tumor tissue to gamma rays.
For this purpose, a cobalt treatment device is used, which has a shielded head equipped with cobalt-60 and a device that precisely controls the exposure required in each specific case to adequately treat the disease. For more information about black holes and their interactions with radiation, you can read our article on supermassive black holes.
The first commercial application of ionization energy dates back to the early 1960s. Currently, there are around 160 irradiation plants in operation worldwide , distributed in more than 30 countries, providing a wide range of services to an increasing number of industries.
As you can see, although they are dangerous, the human being manages to make use of gamma rays in many areas as induced by medicine. I hope that with this information you can learn more about gamma rays and their characteristics.