Identifikation von Beta-Nukliden und Analyse von Mehrfach-Beta-Spektren bei Messungen mit dem Flüssig-Szintillationsspektrometer (LSC)

Tables and graphs are compiled to evaluate mixed spectra from $\beta$ emitters in a liquid scintillation spectrometer. Particular importance is attached to defining quenching behavior via the tSIE value determinable with the device, and thus the associated reduction $\delta$ of the maximum energy of the $\beta$ spectrum (Appendix I). Equally important is the related reduction of the detection probability $\eta$ to values < I for low-energy $\beta$ spectra. With the aid of the efficiency tables (Appendix III), the count rates can be converted into the activity of the specimen for nuclides with a maximum energy of up to 300 keY. In order to identify unknown $\beta$ spectra, a table of long-lived nuclides ordered according to increasing $\beta$ energy is given in Appendix II, and in Appendix IV a graphical representation of the most important $\beta$ spectra on the logarithmic energy scale in an LSC. Several examples of complexly superposed $\beta$ spectra are analysed using these aids. If the identified nuclides are available in the form of standard solutions reference specimens can be produced, the spectracompared and subtracted so that it is generally possible to resolve a complex $\beta$ spectrum into as many as four single spectra