[en] A complete kinematics study of the 1^0B(3^He,pααα) and 1^1B(3^He,dααα) reactions has been performed to study the multi-particle break-up of 1^2C resonances above the triple-alpha threshold. This gives us complete information on the direction and energy of the individual alpha particles from the decay of 1^2C, allowing us to extract new information on the structure of 1^2C which we shall present in this contribution. Using Si charged particle detectors we identified 7 decay of the T=l 15.11 MeV resonance in 1^2C to states above the triple-alpha threshold. This is done by looking for missing energy between the excitation spectra of 1^2C given by the invariant mass of the decay fragments versus the excitation energy given by the primary ejectile (Figure 1, left). We can then extract the branching ratios and compare them to the β decay branching ratios of the IAS of 1^2B and 1^2N measured in a previous experiment by our collaboration. These two results thus gives us a complete picture of the branching ratios of the decay from the A=12 isospin triplet leading to an improved test of the isospin symmetry. Further, we use Dalitzs plots to study the decay of 1^2C resonances into three alpha particles (Figure 1, right). The observed density of the Dalitz plot can be used to determine or at least impose constraints on the spin and parity of the decaying 1^2C resonance as well as provide an understanding of the decay mechanism involved (e.g. sequential vs direct). Dalitz plots can thus allow us to determine spins and parities of resonances in 1^2C. In this contribution we will present our results on the γ branching intensities from the 15.11 MeV state and compare our measured Dalitz distributions to theoretical calculations. The impact of these results on the different models used to describe the structure of 1^2C will be discussed.(author)

[en] Collective structures in ¹⁷⁸Pt have been investigated with γ-ray spectroscopic techniques following mass selection. The present data expand considerably the level scheme of this nucleus. A new collective structure has been identified and the known bands have been extended to higher spins. Firm spin and parity assignments have been made to many levels. Of particular interest are the negative parity bands which are interpreted in terms of structures associated with octupole vibrations crossed at moderate spin by two-quasiparticle excitations. The systematics of the α-decay reduced widths in Pt nuclei has also been investigated. The differences of a factor of about 2 between the widths for the odd- and the even-A isotopes is attributed to changes in neutron pairing associated with the blocking effect. The trend is reproduced in calculations based on the Lipkin-Nogami pairing model. (c) 2000 The American Physical Society

[en] Excited structures in the Z=80, ¹⁷⁸Hg (N=98), and ¹⁸⁰Hg (N=100) isotopes have been investigated with the Gammasphere spectrometer in conjunction with the recoil-decay tagging technique. The present data extend the previously known ground-state bands to higher spin and excitation energy. Negative parity bands with a complex decay towards the low spin states arising from both the prolate-deformed and the nearly spherical coexisting minima have been observed for the first time in both nuclei. It is shown that these sequences have characteristics in common with negative-parity bands in the heavier even-even Hg isotopes as well as in the Os and Pt isotones. These structures are interpreted as being associated at low spin with an octupole vibration which is crossed at moderate frequency by a shape driving, two-quasiproton excitation

[en] The aim of our study was to report Argentine experience in GKS, assessing the efficacy and safety in our patients with pituitary adenomas. We performed a retrospective analysis of patients with pituitary adenomas treated with GKS between 2002 and 2017 in a single institution. Patient characteristics, biochemical remission rate (for functioning tumors), tumor control rate and adverse effects with GKS were investigated. The study cohort comprised 99 patients with a mean follow-up of 63 months: 51 somatotropinomas, 28 non-functioning adenomas, 15 corticotropinomas, 2 prolactinomas and 3 mixed pituitary tumors. The mean radiation dose was 30.6Gy for corticotropinomas, 29.3Gy for somatotropinomas and 19.6Gy for non-secreting adenomas. Global tumor control rate was 94.2%. Biochemical remission rate was 55.9%, being higher in acromegaly than in Cushing’s disease (OR4.7, 95%Ci 2.1-10.4, p<0.0001). The mean time to remission was 29.5 months (range: 6-156). Hypopituitarism occurred in 26% of patients and those with Cushing’s disease were more prone to develop new hormone deficiency after GKS (OR 2.93, 95%Ci 1.2-7.2, p = 0.019). This study shows argentine experience with the use of GKS in patients with pituitary adenomas, with similar results to those reported by centers with large radiosurgical experience. We achieved biochemical remission in more than 50% of patients and global tumor control in most of them. Hypopituitarism was the most frequent adverse effect, while others were infrequent. (authors)

[en] In an experiment performed at the SPIRAL1 facility of GANIL, the β decay of ${}^{32}$Ar has been studied by means of the “Silicon Cube” device associated with germanium clover detectors from the EXOGAM array. Beta-delayed protons and γ rays have been observed and allowed the determination of all relevant decay branches. The Gamow–Teller strength distribution is compared to shell-model calculations and excellent agreement is found. The Fermi strength is inline with expectations. A quasi-complete decay scheme of ${}^{32}$Ar is established.

[en] In the experiment performed at GANIL (France) we have studied the β-delayed particle emission of the T_z = -3/2 ³³Ar and T_z = -2 ³²Ar proton emitters. Protons are emitted within the wide window (around 10 MeV) of excited states in ³³Cl and ³²Cl feeding the ground and the excited states of ³²S and ³¹S. Proton-γ coincidences have been used to determine the B(GT) strength in this region of excitation energy allowing us to reassign proton transitions to higher excited state with respect previous studies. The main motivation to revisit these nuclei is the increase of granularity and sensitivity of the charged particle detectors and the high sensitivity and large angular coverage obtained by the use of the CLOVER detectors.

No abstract available

No abstract available

[en] The mass of ¹¹Li has been determined from Q-value measurements of the ¹H(¹¹Li,⁹Li)³H reaction. The experiment was performed at TRIUMF laboratory with the GANIL active target MAYA. Energy-energy and angle-angle kinematics reconstruction give a Q value of 8.119(22) MeV for the reaction. The derived ¹¹Li two-neutron separation energy is S_2n=363(22) keV

[en] The β -delayed ⁸Li+t branch of the ¹¹Li decay was identified via kinematical analysis of the charged particles observed in coincidence. The back-to-back events observed in a narrow angular acceptance were compared to a Monte Carlo simulation. The ⁸ Li+t sum energy spectrum was fitted assuming that the decay occurs through an intermediate state in ¹¹Be. The resulting energy centroid and full-width half maximum for the intermediate state are 18.35(30) MeV and 1.5(4) MeV, respectively. The β -delayed ⁸ Li+t branching ratio obtained from the coincidence spectrum, BR_t = 0.93(8) x 10^-4, is in agreement with previous measurements but more precise. (orig.)