Uncertainties on gamma-ray energies and intensities measured in the decay of 83Sr

We analyze once again the [Formula: see text] singles spectra and [Formula: see text]-[Formula: see text]-[Formula: see text] coincidence spectra following the [Formula: see text]EC decay of 83Sr. Multipeaks are carefully separated and many [Formula: see text] transition cascades are clearly obtained in the work. As a complement to our previous work, the uncertainties on [Formula: see text]-rays energies, [Formula: see text]-rays intensities and deduced level energies in the [Formula: see text]EC decay of 83Sr are given now.

First measurement of the 2.4 MeV and 2.9 MeV 6He three-cluster resonant states via the 3H(4He, pα)2n four-body reaction

Two new low-lying 6 He levels at excitation energies of about 2.4 MeV and 2.9 MeV were observed in the experimental investigation of the p-α coincidence spectra obtained by the 3 H (4 He , p α)2 n four-body reaction at E4 He beam energy of 27.2 MeV. The relevant E* peak energy and Γ energy width spectroscopic parameters for such 6 He * excited states decaying into the α+ n+n channel were obtained by analyzing the bidimensional (E p , Eα) energy spectra. The present new result of two low-lying 6 He * excited states above the 4 He +2 n threshold energy of 0.974 MeV is important for the investigation of the nuclear structure of neutron-rich light nuclei and also as a basic test for theoretical models in the study of the three-cluster resonance feature of 6 He .

Application of the Triple-Photomultiplier Liquid Spectrometer Hidex 300 Sl in Radiocarbon Dating

The Hidex 300 SL is a liquid scintillation analyzer with an automatic sample changer and a triple-photomultiplier tube detection assembly that registers triple- as well as double-coincidence spectra. In the triple mode, the background in the 14C window is 13.7 cpm (14C standard 30.8 cpm; =154.3 cpm/5.01), so the factor of merit equals 8.7. The triple-to-double coincidence ratio (TDCR) allows for determining the 14C counting efficiency, the quench level, and quench correction. However, in the case of very low-activity samples, which is the case even for modern 14C samples, the TDCR is not the best method for the correction of benzene impurities. We propose using the position (channel) of the right slope of the sample (14C) logarithmic pulse-height spectrum. In the case of near-background samples, the cosmic muon peak can be used instead. The Monte Carlo modeling of spectra gave the 14C level below which the muon peak is a better quench correction parameter than the position of the 14C spectrum. The spectrometer, with the proposed quench correction method, was tested with wood samples dated dendrochronologically. For 21 samples, there is no systematic bias observed, and the standard deviation of the age differences scaled by the Poisson errors is 1.24 ± 0.15, which means that the counting statistics account for 80% of the total variability (including sample preparation).