Decay Spectroscopy Experiments Research Articles

Imaging algorithm for background suppression in the planned gamma tracking array of DESPEC

For DEcay SPECtroscopy (DESPEC) experiments with implanted radioactive beams a high resolution gamma tracking array is being designed at GSI. Exploiting the imaging capability of the array, a background suppression method is developed based on a separation of events originating from the target and from localized background sources. Monte-Carlo simulations show that the suppression of the background by a factor from 10 up to 100 or even more can be achieved. The Peak/Total ratio can be as well significantly increased. The dependence of the suppression efficiency on the detector properties is discussed.

Beta-decay studies at the N=28 shell closure

First results on a β-γ decay spectroscopy experiment of nuclei in the region of N=28 are reported. New β half-lives for nuclei from Mg to Ar have been extracted. For the heavier ones, the new periods of 48 Ar and 47 Cl are of importance in the understanding of solar abundance ratio 48Ca 46Ca . The measured half-lives of Si isotopes have been extended from N=25 to N=28 and are discussed in the light of possible deformation occuring in this region. Finally, preliminary spectroscopy of 45 Ar is also reported.

Estimation of the optimum pulse repetition rates in single photon decay spectroscopy experiments

This paper presents a theoretical and experimental study of the optimum repetition rates of the excitation pulses in single photon decay spectroscopy experiments using an alternative technique to measurement of the time interval distribution function for the arrival of the first photoelectron, Pf(t). This technique involves direct measurement of the sine transform from the time intervals, ti, obtained after the excitation pulse. The influence of pulse repetition on the accuracy with which the decay time can be obtained is discussed in terms of the background noise superimposed on the fluorescence signal. A set of experiments was carried out with a TMMC crystal for comparison with the theoretical predictions.

Experimental Application of the Fourier Transform of the Time-Interval Probability Technique to Lifetime Measurement

In this paper the Fourier transform of the time-interval probability (FT-TIP) technique is applied to a fluorescence decay spectroscopy experiment in which a very small signal is detected. The lifetime of the 4 F9/2, level of Er3+ ions in an Er-doped glass is measured by the FT-TIP technique. It is concluded that this technique can be applied to lifetime measurement with small errors, in those experiments where standard techniques do not work well because of the small detected signal.