What is radioisotope dating - POLATOM | Narodowe Centrum Badań Jądrowych Ośrodek.


The decay of 238 U and 235 U to 206 Pb and 207 Pb, respectively, forms the basis for one of the oldest methods of geochronology (Dickin 2005; Faure and Mensing 2005). While the earliest studies focused on uraninite (an uncommon mineral in igneous rocks), there has been intensive and continuous effort over the past five decades in U-Pb dating of more-commonly occurring trace minerals. Zircon (ZrSiO 4 ) in particular has been the focus of thousands of geochronological studies, because of its ubiquity in felsic igneous rocks and its claimed extreme resistance to isotopic resetting (Begemann et al. 2001).

The isotope U-235 is important because under certain conditions it can readily be split, yielding a lot of energy. It is therefore said to be 'fissile' and we use the expression 'nuclear fission'.

Nuclear density gauges can also be used to measure the density of a liquid in a pipe. If a source is mounted on one side of a pipe and a detector on the other, the amount of radiation seen at the detector is dependent upon the shielding provided by the liquid in the pipe. Tracerco pioneered the use of radiation to measure density in the 1950s and determined that the Beer–Lambert law also applied to radiation as well as optics. Gauges are normally calibrated using gas and a liquid of known density to find the unknowns in the equation. Once it has been calibrated and as long as the source detector alignment remains constant, it is possible to calculate the density of the liquid in the pipe. One factor is the half life of the radioactive source (30 years for 137 Cs), which means that the system needs to be recalibrated at regular intervals. Modern systems incorporate correction for source decay. [1]


What is radioisotope dating

What is radioisotope dating