Chapter 11 from BASICS OF NUCLEAR PHYSICS AND OF RADIATION DETECTION AND MEASUREMENT - An open-access textbook for nuclear and radiochemistry students by Jukka Lehto

In an ordinary radiochemical laboratory the alpha-emitting radionuclides studied are those listed in Table XI.I. Of these Po, Ra, Th and U isotopes are naturally occurring radionuclides while Pu and Am isotopes are artificial transuranium nuclides. The natural alpha-emitting radionuclides belong to the decay series beginning from ²³⁸U, ²³⁵U and ²³²Th. The sources of the transuranium elements are the the nuclear weapons tests in the 1950' and 1960's and of the Chernobyl accident in 1986 as well as the nuclear waste, especially the spent nuclear fuel. Some of these radionuclides, such as ²³⁵U, ²²⁶Ra and ²⁴¹Am emit gamma radiation, which can in some cases be used for their measurement. The intensities and/or gamma ray energies are, however, typically so low that the gamma spectrometric measurement does not yield accurate results. Moreover, gamma spectrometry does not allow determination of isotopic composition of uranium, which is important information in many studies. Accurate measurements, enabling also determination of isotopic compositions, are obtained either by alpha spectrometry of by mass spectrometry. The former is discussed here in this chapter.

Table XI.I. Most typical alpha-emitting radionuclides studied in radiochemical laboratories.