The first gamma ray source to be discovered was the radioactive decay process called gamma decay. We can solve this problem one of two ways:. Fig 3. Gamma radiation is mostly used when the primary tumor has been surgically removed but the oncologist still believes that clusters of cancerous tumors are still present, and also when the tumor has been detected in an early stage and can be treated using strong gamma radiations. As in optical spectroscopy see Franck—Condon effect the absorption of gamma rays by a nucleus is especially likely i. Gamma-ray astronomy did not develop until it was possible to get our detectors above all or most of the atmosphere, using balloons or spacecraft. Journal of Instrumentation.
11.6: Penetrating Power of Radiation
Because of the large mass of the alpha particle, it has the highest ionizing power and the greatest ability to damage tissue. In general, the greater mass present the greater the ionizing power and the lower the penetration power. Gamma rays may pass all the way through a human body without striking anything. The ability of radiation to damage molecules is analyzed in terms of what is called ionizing power. With all the radiation from natural and man-made sources, we should quite reasonably be concerned about how all the radiation might affect our health. Once again, however, the greatest danger occurs when the beta emitting source gets inside of you. They are also stopped by the outer layer of dead skin on people.
Penetrating Power of Radiation - Chemistry LibreTexts
Beta particles are much smaller than alpha particles and therefore, have much less ionizing power less ability to damage tissue , but their small size gives them much greater penetration power. They are also stopped by the outer layer of dead skin on people. Many centimetres of lead or many meters of concrete are required to absorb high levels of gamma rays. In most cases, radiation will damage a single or very small number of cells by breaking the cell wall or otherwise preventing a cell from reproducing. These interactions can alter molecular structure and function; cells no longer carry out their proper function and molecules, such as DNA, no longer carry the appropriate information.
Description: The animation below shows the penetrating properties of radiations. Gamma rays may pass all the way through a human body without striking anything. That same large size of alpha particles, however, makes them less able to penetrate matter. This may seem to remove the threat from alpha particles but only from external sources. The greater the likelihood that damage will occur by an interaction is the ionizing power of the radiation.