A gamma ray is electromagnetic radiation of the shortest wavelength and highest energy. Gamma-ray radiation has wavelengths generally smaller than a few tenths of an angstrom (10−10 meter), and gamma-ray photons have energies greater than tens of thousands of electron volts.
Gamma rays are ionizing electromagnetic radiation, obtained by the decay of an atomic nucleus. Gamma rays are more penetrating, in matter, and can damage living cells to a great extent. Gamma rays are used in medicine (radiotherapy), industry (sterilization and disinfection) and the nuclear industry.
SOURCES OF GAMMA RAYS They are produced by the hottest and most energetic objects in the universe, such as neutron stars and pulsars, supernova explosions, and regions around black holes. On Earth, gamma waves are generated by nuclear explosions, lightning, and the less dramatic activity of radioactive decay.
Gamma rays are kind-of like light, which is a form of energy that travels in waves. Gamma rays have a LOT more energy than light and you cannot see them. Any energy that travels in waves is a form of radiation and is part of the electromagnetic spectrum.
Gamma rays (γ) are weightless packets of energy called photons. Unlike alpha and beta particles, which have both energy and mass, gamma rays are pure energy. Gamma rays are similar to visible light, but have much higher energy. Gamma rays are often emitted along with alpha or beta particles during radioactive decay.
Examples of gamma rays are found in radioactive decay of naturally-occuring radionuclide, lightning (terrestrial gamma-ray flashes), and nuclear explosions. Gamma rays are also found in black holes, supernova remnants, and gamma-ray bursts.
The extremely high energy of gamma rays allows them to penetrate just about anything. They can even pass through bones and teeth. This makes gamma rays very dangerous. They can destroy living cells, produce gene mutations, and cause cancer.
Intense beams of gamma rays would find a host of uses in fundamental physics research, nuclear fusion, and medicine, but they are hard to produce. A team has now used computer simulations to show that a powerful laser hitting a plastic surface can generate intense gamma-ray emission.
Importance in Clinical Medicine The fact that gamma rays kill any living organism is an advantage to the medical field, especially the field of oncology. High doses of gamma rays can kill cancerous cells in a process called radiation therapy (lower doses could lead to cells becoming cancerous).
Gamma rays can be helpful as well as harmful (and are very unlikely to turn you into the Hulk). To destroy brain cancers and other problems, medical scientists sometimes use a "gamma ray knife." This consists of many beams of gamma rays focused on the cells that need to be destroyed.
A gamma ray packs at least 10,000 times more energy than a visible light ray. Unlike the Incredible Hulk, gamma rays are not green — lying as they do beyond the visible spectrum, gamma rays have no color at all that we can describe.
Natural sources of gamma rays on Earth include gamma decay from naturally occurring radioisotopes such as potassium-40, and also as a secondary radiation from various atmospheric interactions with cosmic ray particles.