Gamma Rays and its Properties

Gamma Radiations

The electromagnetic spectrum includes all waves, but gamma rays are the most energetic and have the shortest wavelengths. The solar system’s hottest and most powerful objects produce them, including neutron stars and cosmic rays, supernova explosions, and zones near black holes. Similarly, on earth, nuclear explosions, lightning, and various dramatic processes of radioactive decay all produce gamma radiation.

Discovery of Gamma Radiation

In 1900, Paul Villard, a French physicist and chemist discovered evidence of gamma radiation. Villard was researching the radiation that the element radium emits. Villard remarked that radium’s radiation was more intense than the beta radiation recorded by Becquerel in 1896 or the alpha rays reported by Rutherford in 1899. Still, he did not classify gamma radiation as a novel type of radiation.

In 1903, Ernest Rutherford expanded on Villard’s term and gave the energetic radiation the moniker “gamma rays.” Alpha radiation penetrates substance the least, beta radiation penetrates substance more, and gamma radiation penetrates substance the most. It is reflected in the name.

Gamma Radiation Definition

What is gamma radiation? An electromagnetic energy (photon) packet known as gamma radiation (g) is released by the nucleus of certain radionuclides after radioactive decay. The electromagnetic spectrum’s most energetic photons are known as gamma photons.

Apart from optical light and x-rays, gamma particle cannot be collected and projected by reflectors. Since the wavelengths of gamma rays are so short, they can traverse the area between atoms in a detector. Blocks of crystal are often tightly packed in gamma-ray detectors. Gamma rays strike the crystal’s electrons as they travel through it. Gamma rays release energy when they impact an electron in a process known as Compton scattering, which is analogous to when a cue ball hits an eight ball. These collisions produce detectable charged particles.

Interesting Facts: High-frequency electromagnetic radiation such as gamma rays has a high energy density. They can go through the majority of materials. Their transmission can only be halted by an absorber, like a lead block or a substantial concrete block. In many alpha and beta transitions, the leftover nucleus forms in an energized state. There are various ways the nucleus can shed its vibrational energy and transition to a “fundamental level.”

Natural Sources of Gamma Rays

Gamma radiation can be found in a variety of natural settings. These consist of:

Gamma Decay is the process through which naturally occurring radioisotopes emit gamma radiation. Gamma decay, in which the excited daughter nucleus disintegrates to a lower energy level by producing a gamma radiation photon, frequently follows alpha or beta decay. However, nuclear fission, fusion, and neutron absorption can also cause gamma decay.

Antimatter Annihilation: When an electron and a positron collide during antimatter annihilation, some ultrahigh gamma particle is produced. Synchrotron radiation, bremsstrahlung, Compton scattering, and neutral pion decay are other subatomic origins of gamma radiation in addition to gamma decay and antimatter.

Lightning: A geological gamma-ray flash results from lightning’s supercharged electrons.

Solar flares: The electromagnetic radiation, including gamma radiation, may be emitted by a solar flare.

Cosmic rays: Through bremsstrahlung or pair creation, cosmic rays interact with substances to produce gamma rays.

Gamma-ray bursts: When neutron stars interact or when a neutron star encounters a black hole, resulting in a powerful discharge of gamma radiation.

Other celestial sources: Pulsars, quasars, magnetars, and galaxies all emit gamma radiation that is studied by astrophysics.

What distinguishes gamma radiation from X-rays?

X-rays and gamma rays are both two forms of electromagnetic energy. Now, what distinguishes them since both their electromagnetic spectrums overlap? Well, gamma particle or rays, which come from nuclear decay, distinguish the two types of radiation, whereas x-rays come from the electron cloud surrounding the nucleus. According to astronomers, their energy is the only difference between gamma radiation definition and x-rays. X-rays only have photon energies up to 100 keV, but gamma radiation has photon energies over 100 keV.

Properties of Gamma Radiation

Gamma radiation is a form of electromagnetic radiation (EMR). Only the fact that they are released from an energized nucleus sets them apart from X-rays. A sequence of photons, massless particles that move at the speed of light and each traveling in a wave-like pattern, can be used to model electromagnetic radiation. All electromagnetic radiation is made of photons, each of which has a specific amount (or bundle) of energy. In the EMR spectrum, gamma-ray photons have the most energy and the shortest wavelength.

In electron volts, scientists gauge the energy of photons (eV). The energy of X-ray photons ranges from 100 eV to 100,000 eV. (or 100 keV). The majority of gamma-ray photons have an energy of more than 100 keV. In contrast, UV radiation doesn’t even have enough energy to be categorized as ionizing radiation because its energy ranges from a few electron volts to around 100 eV. Gamma rays can easily penetrate through various materials due to their tremendous energy, including biological systems. Gamma rays are frequently suppressed or slowed down by shielding made of some very solid objects, like lead.

Gamma Rays Uses 

The most often utilized radiation sources are radionuclides that generate gamma radiation. The penetrating ability creates numerous gamma ray uses. Gamma rays can absorb a wide range of materials. However, this does not turn the materials radioactive. Caesium-137, cobalt-60, technetium-99m, and americium-241 are the most beneficial radionuclides. 

Gamma Rays Uses Caesium-137:

• Measuring and regulation of fluid flowing in manufacturing applications.
• Examination of underground stratum (i.e., coal, oil, gas, and other mineralization.
• Soil moisture-density measurements at work sites
• Leveling standards for food, medicine, and other product packaging.

Gamma Rays Uses Cobalt-60:

• Disinfection of medical devices and equipment in hospitals
• Pasteurization of foods
• Commercial radiography
• Thickness gauges or leveling (for example, steel mills, food packaging)

Gamma Rays Uses Technetium-99:

• Tc-99 is the most popular radioactive isotope used in medical diagnostic research.
• It is used in imaging the bone, brain, liver, spleen, and kidneys, along with various other chemical forms. 
• Studies on blood flow also employ it.

Gamma Rays Uses Americium-241:

Smoke detectors in homes

Density gauges and fluid leveling

Thickness gauges for thin substances (i.e., foil, paper, glass)

Air and spacecraft fuel gauges

Americium-241 forms a 241AmBe neutron source when combined with beryllium, which is used in tomography, neutron imaging, and well monitoring.

Interesting Facts: Scientists can use gamma rays to identify the elements in distant worlds. The gamma-ray spectrometer (GRS) on board the Mercury Surface, Space Environment, Geochemistry and Ranging (MESSENGER) spacecraft may detect gamma rays released by atom nuclei on the planet Mercury’s surface after being impacted by cosmic rays. Chemical components in soils and rocks release distinctly recognizable traces of energy in the form of gamma rays when cosmic rays strike them. These data can aid researchers in their search for geologically significant elements like sodium, magnesium, calcium, oxygen, silicon, iron, and titanium.

What negative consequences on health might gamma radiation exposure have?

High-penetration gamma radiation interacts with matter by ionizing it through three processes: Compton scattering, the photoelectric effect, and pair creation. Despite being less harmful than alpha particles, the impacts of gamma radiation can be felt all through the person due to its strong capacity to penetrate. Regarding radiation safety, gamma radiation is regarded as an external threat. 

High exposures to gamma rays can have direct acute consequences by causing instant cell damage, just like any other exposure to radiation. A stochastic health risk is present at low exposure levels, where the likelihood of developing cancer increases with exposure.

Conclusion

• The segment of the electromagnetic spectrum with the highest energy and shortest wavelength is known as gamma radiation (gamma rays).
• What is gamma radiation? It is any radiation with an energy of more than 100 keV. Physicists define gamma radiation as highly energetic photons produced during nuclear decay.
• In 1900, Paul Villard discovered gamma radiation.
• According to a more elaborative gamma radiation definition, gamma rays are produced by a variety of celestial sources as well as by lightning, solar radiation, matter-antimatter annihilation, cosmic ray interactions with matter, and thunder.
• In addition to being used to clean gemstones, analyze containers, sterilize food and equipment, detect medical disorders, and treat some types of cancer, gamma radiation is also utilized to research the universe.

Frequently Asked Questions 

1. What is gamma radiation?

Gamma rays are electromagnetic radiation with the smallest wavelength and maximum energy levels. The wavelengths of gamma radiation are often less than a few tenths of an angstrom (10 – 10 meters), yet the energy of gamma photons exceeds tens of thousands of electron volts.

2. How are gamma rays formed?

Gamma rays are formed when radioactive atomic nuclei disintegrate and some subatomic particles decay. Pair destruction, in which two photons are created along with the disappearance of an electron and its antiparticle, a positron, also results in the formation of gamma rays. Additionally, they can be produced when some volatile subatomic particles, such as the neutral covalent bond, decay.

3. Who came up with the term “gamma radiation”?

After preliminary research on the radioactive nuclei’s emissions, in 1903, British physicist Ernest Rutherford came up with the term “gamma ray”.

4. What medical use do gamma rays have?

The imaging method of positron emission tomography (PET) and radiation therapy to treat malignant tumors are two examples of how gamma rays are used in medicine.