Gamma Radiation - Rayner, Preston, Christopher

Gamma Rays have the highest frequency in the electromagnetic spectrum. There are many uses for it like radiation treatment, sterilizing, etc. But they are also very dangerous. They can cause radiation sickness and eventually, death after long term exposure.
A short video about Gamma Radiation: http://www.youtube.com/watch?v=okyynBaSOtA
A short video about Alpha, Beta and Gamma Radiation: http://www.youtube.com/watch?v=TSiNXBLfzK4


Source:
- Neutron stars
- Cobalt 60
- Decay of high energy states in atomic nuclei & high energy sub-atomic particle interactions in natural processes and man made mechanisms


Uses:
- For radiation therapy. It turns out that though electromagnetic radiation(emr) damage can make living cells "sick" and can also kill them if enough damage occurs, the cells that are most sensitive to emr damage are cells that have "fast metabolisms" or that work at high rates. Cancer cells work at high rates. Irradiate them with high energy emr (gamma rays) and they can be killed. So will some surrounding tissue, but the brunt of the damage will be caused to the cancerous tissue. And by moving the beam around, we can minimize damage to surrounding tissue while pounding the cancerous cells. This is the basis for currentradiation therapy by gamma rays.
- Sterilization of surgical equipments to remove viruses and micro-organisms.
- Gamma-induced molecular changes can also be used to alter the properties of semi-precious stones, and is often used to change white topaz into blue topaz.
- Gamma rays are also used for diagnostic purposes in nuclear medicine in imaging techniques. A number of different gamma-emitting radioisotopes are used. For example, in a PET scan a radiolabled sugar called fludeoxyglucose emits positrons that are converted to pairs of gamma rays that localize cancer (which often takes up more sugar than other surrounding tissues). The most common gamma emitter used in medical applications is the nuclear isomer technetium-99m which emits gamma rays in the same energy range as diagnostic X-rays. When this radionuclide tracer is administered to a patient, a gamma camera can be used to form an image of the radioisotope's distribution by detecting the gamma radiation emitted (see also SPECT). Depending on what molecule has been labeled with the tracer, such techniques can be employed to diagnose a wide range of conditions (for example, the spread of cancer to the bones in a bone scan).


Risks:
- Gamma radiation can break and split DNA molecules
- They are absorbed or scattered by anything they pass through, and their ability to penetrate material and the amount of scattering they experience varies as the material. But they penetrate stuff pretty well, and slice right through biological stuff like plant or animal tissue. And they do stuff to the tissue they pass through while zipping past.

The high energy of gamma rays is what is called ionizing radiation. It has the power to break chemical bonds between atoms. This is important because living tissue is made up of complex chains of atoms. Big organic molecules are the basics of life. If a gamma ray zips by, it can break the big molecule apart kind of like snipping a string in a place or two with scissors. The gamma ray loses energy doing this, but it still continues on cutting up molecules. It causes radiation damage. Electromagnetic radiation (emr) damage. And this can be good.


Summary:
- Gamma radiation has the highest frequency in the electromagnetic spectrum.
- Its source is the decay of high energy states in atomic nuclei & high energy sub-atomic particle interactions in natural processes and man made mechanisms, neutron stars, Cobalt 60
- Uses are: To eradicate cancer cells, alter properties of semi-precious stones, sterilization of equipments, diagnostic purposes in nuclear medicine in imaging techniques.
- Risks: It can kill you and split your DNA