Why is gamma radiation used

In medicine Sterilisation surgical instruments Gamma rays are high energy electromagnetic waves which are only stopped by thick lead. The gamma ray source used should have a long half-life so that the hospital does not have to replace it too frequently Advantages sterilisation can be done without high temperatures; it can be used to kill bacteria on things that would melt e.

Radiotherapy: killing cancerous tumours. A patient undergoing radiotherapy. If you could see gamma-rays, these two spinning neutron stars or pulsars would be among the brightest objects in the sky. This computer processed image shows the Crab Nebula pulsar below and right of center and the Geminga pulsar above and left of center in the "light" of gamma-rays.

The Crab nebula, shown also in the visible light image, was created by a supernova that brightened the night sky in A. In , astronomers detected the remnant core of that star; a rapidly rotating, magnetic pulsar flashing every 0.

Perhaps the most spectacular discovery in gamma-ray astronomy came in the late s and early s. Detectors on board the Vela satellite series, originally military satellites, began to record bursts of gamma-rays -- not from Earth, but from deep space! Today, these gamma-ray bursts, which happen at least once a day, are seen to last for fractions of a second to minutes, popping off like cosmic flashbulbs from unexpected directions, flickering, and then fading after briefly dominating the gamma-ray sky.

Gamma-ray bursts can release more energy in 10 seconds than the Sun will emit in its entire 10 billion-year lifetime! So far, it appears that all of the bursts we have observed have come from outside the Milky Way Galaxy.

Scientists believe that a gamma-ray burst will occur once every few million years here in the Milky Way, and in fact may occur once every several hundred million years within a few thousand light-years of Earth. Studied for over 25 years now with instruments on board a variety of satellites and space probes, including Soviet Venera spacecraft and the Pioneer Venus Orbiter, the sources of these enigmatic high-energy flashes remain a mystery.

By solving the mystery of gamma-ray bursts, scientists hope to gain further knowledge of the origins of the Universe, the rate at which the Universe is expanding, and the size of the Universe. 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. Gamma rays are a radiation hazard for the entire body. They can easily penetrate barriers that can stop alpha and beta particles, such as skin and clothing. Gamma rays have so much penetrating power that several inches of a dense material like lead, or even a few feet of concrete may be required to stop them. Gamma rays can pass completely through the human body; as they pass through, they can cause ionizations that damage tissue and DNA.

Because of their use in medicine, almost everyone has heard of x-rays. X-rays are similar to gamma rays in that they are photons of pure energy. X-rays and gamma rays have the same basic properties but come from different parts of the atom. X-rays are emitted from processes outside the nucleus, but gamma rays originate inside the nucleus.

They also are generally lower in energy and, therefore less penetrating than gamma rays. X-rays can be produced naturally or by machines using electricity. Literally thousands of x-ray machines are used daily in medicine.

Computerized tomography, commonly known as a CT or CAT scan, uses special x-ray equipment to make detailed images of bones and soft tissue in the body. Medical x-rays are the single largest source of man-made radiation exposure. Learn more about radiation sources and doses. X-rays are also used in industry for inspections and process controls. Elements in the periodic table can take on several forms. Some of these forms are stable; other forms are unstable.

Typically, the most stable form of an element is the most common in nature. However, all elements have an unstable form.