[en] A method is presented for the detection of charged particles emitted in the β-decay of exotic nuclei. Direct implantation of radioactive nuclei in a very thin double-sided silicon strip detector is now feasible thanks to the advances in the production and post-acceleration of ISOL beams. The high degree of pixelazation, and consequently the small active volume of the detector, and the precise energy of the radioactive ion beam are the key features of the method. Among the advantages of the method are a good precision of the overall normalization and a reduction of the background due to β-radiation. Several developments are described in the present paper. The detection threshold at low energies is determined using pulsed signals. An alternative energy calibration for the decay events, free from any dead-layer effects can be performed by implanting radioactive ions decaying to known narrow resonances, e.g. ²⁰Na. Time and position correlations in a small detection volume can be used to identify possible different decay channels. An overview of precision measurements using this technique is given to prove the strength of the method.

[en] We measured the β-decay of the halo-nucleus ¹¹Li, with particular attention to the deuteron- and triton-emission channels. We employed a post-accelerated beam of ¹¹Li ions, and the implantation technique in a finely-segmented silicon detector. The channels of interest were identified through the time and space correlations between the implantation events and the parent and daughter decays. We obtained the branching ratios, as well as the spectra of the emitted ions

[en] We measured the deuteron-emission branch of the β decay of the halo nucleus ⁶He using the technique of implantation into a highly segmented silicon detector. The method, used here for the first time with a beam of ⁶He ions, ensures precise normalization; the value obtained for the branching ratio is B=(1.65±0.10)x10^-6 (6% error). The summed energy spectra of the emitted α and d particles has also been measured. The results allow us to compare calculations from various models, potentially setting strong constraints on the precision required for the description of the ⁶He ground-state wave function.

[en] The deuteron-emission channel in the β decay of the halo nucleus ¹¹Li was measured at the Isotope Separator and Accelerator facility at TRIUMF by implanting postaccelerated ¹¹Li ions into a segmented silicon detector. The events of interest were identified by correlating the decays of ¹¹Li with those of the daughter nuclei. This method allowed the energy spectrum of the emitted deuterons to be extracted, free from contributions from other channels, and a precise value for the branching ratio B_d=1.30(13)x10^-4 to be deduced for E_c.m.>200 keV. The results provide the first unambiguous experimental evidence that the decay takes place essentially in the halo of ¹¹Li and that it proceeds mainly to the ⁹Li+d continuum, opening up a new means to study the halo wave function of ¹¹Li