Beta-Counters / Gamma-Counters

In principle, three main types of nuclear decay can be distinguished: the alpha, beta and gamma decay. If the alpha decay is concerned, the atomic number of the radioactive element decreases by 2 and the mass number by 4. This is the result of emitting an alpha particle which consists of two protons and two neutrons. In beta^– decay, an electron is emitted, raising the atomic number of the isotope by 1. Gamma decay is a by-product of alpha and beta decays. Mass and atomic number do not change here, only the excited state of the nucleus does. If the excited nucleus returns to its initial condition, a gamma quantum is emitted.

Beta radiation

Beta radiation is an ionising radiation. It is caused by radioactive decay. In most cases this means β^– radiation, consisting of electrons, although β⁺ radiation of positrons may as well occur. In beta decay, a high-energy beta particle - whether electron or positron – thus exits from the nucleus. Beside this high-energy particle there originates, in addition, an antineutrino or a neutrino.

Gamma radiation

Gamma radiation, γ radiation, is a very pervasive electromagnetic radiation which originates from the decay of nuclei of radioactive nuclides. It has an energy of about 200 keV. Gamma radiation is thus the result of radioactive decay, as for example of alpha or beta decay. The remaining nucleus is in excited state. If this nucleus drops again to a state of lesser energy, such as the initial condition, a certain energy amount will be emitted in the form of gamma radiation.

Literature

• http://de.wikipedia.org/w/index.php?title=Gammastrahlung&oldid=87038108 (called: 31.03.11).
• http://de.wikipedia.org/w/index.php?title=Radioaktivit%C3%A4t&oldid=87044482 (called: 31.03.11).
• http://de.wikipedia.org/w/index.php?title=Betastrahlung&oldid=86935705 (called: 31.03.11).