Gamma rays are electromagnetic radiations that have the shortest wavelength of all electromagnetic waves; therefore, they are the most energetic form of light existing in nature. The wavelength of the gamma rays is less than 100 picometers, and the frequency is greater than about {10}^{19} hertz. The gamma rays were first observed by the French chemist Paul Villard in the year 1900 while he was studying the radiations emitted from radium. Later, in 1903, a British chemist and physicist, Ernest Rutherford, coined the term ‘gamma rays’ for the first time. Gamma rays are produced by four types of nuclear reactions, namely, fusion, fission, alpha decay, and gamma decay.
Examples of Gamma Rays
1. Gamma-Ray Astronomy
One of the prominent use of gamma rays in real life lies in the field of astronomy. Gamma-ray bursts are one of the major sources of gamma rays. It was initially believed that the GRBs or gamma-ray bursts originate from the last stages of evaporating mini black holes, but according to the new theories, the gamma-ray bursts originate due to the collision of dense cosmic objects such as neutron stars. Hence, gamma rays help astronomers study the phenomena like stars exploding, celestial collisions, matter falling in blackholes, etc., and to get a better understanding of the universe.
Gamma ray bursts
2. Food Sterilization
Gamma rays are mostly used for the sterilization of food because gamma rays are high energy radiations that can penetrate through rigid objects easily, thereby ensuring deep sterilization by killing the bacteria, pathogens, and insects present in the food items. Another advantage of using gamma rays to sterilize food is that they are suitable for all types of food items including dry, moist, and frozen food items. The sterilization of food with the help of gamma rays is one of the most reliable methods of sterilization used by food factories.
3. Sterilization of Medical Equipment
Gamma rays are used in the medical field for the purpose of sterilization of surgical instruments. The irradiation of the surgical equipment with high energy gamma radiations cause the bacterial DNA to break down, thereby preventing the microorganisms to undergo any further division and reproduction. Hence, the bacteria and germs exposed to the gamma rays get killed, and the medical instrument gets thoroughly sterilized.
4. Radio Therapy
Gamma rays are mostly used in radiotherapy to cure chronic diseases such as cancer and tumours by killing the DNA of the cancerous cells. Gamma rays are highly energetic in nature, which is why they can also cause damage to healthy cells. Hence, they must be used cautiously. The chances of causing injury to the healthy cells can be reduced by directing multiple gamma-ray beams from a linear accelerator onto the target region from different directions.
5. Tracers in Medicine
Medical tracers are typically used to identify the root cause of problems inside the body. The medical tracers are the radioactive isotopes of elements that are inserted inside a person’s body via injections, or with the help of swallowable pills. The location of the isotopes or the medical trackers can be traced by tracking the radiations emitted by them. This helps the doctors and medical professionals verify whether the organs of a person are functioning properly or not. The health of the body organs can be estimated by noting the amount of substance absorbed by certain parts of the body. Gamma rays are used in medical tracers because they are comparatively less harmful in nature than alpha and beta rays. Also, the radioactive isotopes used in the medical tracers have a short life span, which is why they soon tend to become inactive and harmless.
6. Irradiation of Art Objects
Gamma rays are mostly used by museums and art studios to restore or preserve a piece of art. For the purpose of restoring an art piece, the object is exposed to high-frequency gamma rays. The high energy possessed by such a ray tends to weaken the molecular structure of the object, causing it to emit radiation. This allows the researcher to know about the chemical composition of the art object.
7. Gamma-Ray Spectroscopy
Gamma radiations find their prime application in spectroscopy. They can be used to identify various radioactive isotopes in a sample. The advantage of gamma rays spectroscopy is that it is undestructive and produces results at a faster rate. Another advantage is that the Gamma rays based spectroscopy instruments are portable and can be used for both relative and absolute measurements. The limitation of gamma-ray spectroscopy is that they require regular energy and efficiency calibrations, and the measurements are incorrect if the sample size is large, dense, or heterogeneous.
Gamma-ray spectroscopy instrument
8. Measure Water and Oil Fluid Level in Industries
Gamma rays are generally used in industries to measure the level of fluids. The fluids subjected for level measurement are generally water or oil. The radiations emitted from a source enter the vessel and get attenuated gradually. The detector placed on the opposite side measures the strength of the radiations passing through the container. The magnitude of radiations emitted and detected is then used to determine the fluid level. The process requires frequent calibration based on the type of fluid present in the vessel.
9. Alter Properties of Precious Stones
Gamma rays are highly energetic in nature. This characteristic of gamma radiations can be used in altering the basic properties of precious stones and gems. The stones and gems are artificially irradiated with gamma rays to enhance their optical properties. The high energy possessed by the gamma rays tends to change the fundamental atomic structure of the gems and stones, which provides an enhanced look to the sample substance.
10. Gamma-knife Surgery
Gamma knife surgery is a form of radiation therapy that makes use of gamma rays to cure tumours, cancers, vascular malformations, and other abnormalities of the brain. The gamma knife surgery does not require open surgery, and it is purely a form of stereotactic radiosurgery. It is non-invasive and is comparatively safer than standard neurosurgery. It makes use of a machine that emits approximately 200 beams of radiation onto the target area. The radiation beams are highly directional and tend to kill only the infected cell, leaving the healthy cells unharmed. Gamma knife surgery is preferred in case the normal procedure of surgery is risky, or the infected organ is hard to reach.
11. Medical Imaging
Medical imaging is one of the prominent applications of gamma rays in real life. It makes use of various tiny radioactive tracers that are injected into the patient’s body. The high energy gamma radiation emitted by the tracers then gets detected by the gamma camera present in the scanner machine, thereby allowing the medical person in charge to process the detected signals and get a clear image of the internal organs and structures of a living being without any invasion. This helps in diagnosing a number of problems such as tumour, infection, thyroid, fractures, inflammation, etc. The image of the internal body organs formed with the help of gamma rays-based imaging machines can be either two-dimensional or three-dimensional in nature.
12. Mineral Exploration
Gamma rays find their prime application in geology, i.e., in mineral exploration, mining, and study of elements. It involves studying the core structure of certain minerals. For this purpose, gamma-rays are highly preferred because they provide rapid results and form a reliable method of study. It also enables scientists to find ores of various elements. Gamma-ray spectroscopy helps in the mining, exploration, and monitoring of elements present beneath the earth’s crust.
Mineral mining and exploration