For example, in a thick (1 µm) solid Rb sample, attenuation is so severe that a false frequency maximum is generated at about 10 ke V. One way this attenuation problem has been avoided is to use a photo-multiplier with a liquid scintillation solution doped with Rb.
Instead, Rb is a dispersed element in trace amounts in other minerals.
For example, it occurs in easily detectable amounts in common K-bearing minerals, such as the micas (muscovite, biotite, phlogopite and lepidolite), K-feldspars (orthoclase and microcline), certain clay minerals, and the evaporite (precipitite) minerals sylvite and carnallite. The latter is the time it takes for half of a given number of the parent radionuclide atoms to decay.
Rb half-life and decay constant, there is still no consensus on the absolute values.
Even the more accurate determinations of the last 30 years have resulted in discrepancies.
The proportional counter has a much lower noise level, so the energy cut-off can be set as low as 0.185 ke V.
Rb films with thicknesses down to 1 µm were measured by Neumann and Huster (1974), and extrapolated to zero thickness by Neumann and Huster (1976) to derive a ).
The β-particles will be absorbed by molecules of the scintillator (emitting flashes of light) before they can be absorbed by other Rb atoms.
The major problem with this method is that a low-energy cut-off at about 10 ke V must be applied to avoid the high background noise associated with liquid scintillation (Dickin 2005). Cambridge, United Kingdom: Cambridge University Press.
This has resulted in suggested values of the Rb decay rate has thus not been accurately determined, the Rb-Sr dating method is certainly not absolute and therefore cannot be used to discredit the young-earth creationist timescale.