DAMA/R&D

Investigation of β decay of 113Cd

2007 - Beta decay of 113Cd was studied with the help of a low background CdWO4 crystal scintillator (mass of 434 g):

    113Cd → 113In       Qβ = (320 ± 3) keV

The number of 113Cd nuclei was determined with the precise mass-spectrometric measurements of cadmium isotopes abundances in the CdWO4 crystal, i.e. with a higher accuracy than in the previous experiments. The background of the detector was reconstructed on the basis of a careful analysis both of the data of the low-background experiment, and of the ICP-MS measurements of the CdWO4 contamination. All these improvements have allowed the determination with a better accuracy than in other measurements of the spectral shape of the 113Cd β decay and its half-life:

T1/2 = (8.04 ± 0.05) x 1015 yr

In the figure is depicted the raw spectrum, which points out the presence beta spectrum of 113Cd (red line), the model of the background and its main components.