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Active targets are perfect tools for the study of reactions induced by radioactive ion beams of very low intensity. Thus, they make possible the study of direct and compound reactions at the same time. In this talk, we will present the results obtained with the MAYA active target for low energy reactions induced by the halo nucleus 11Li. A method used to measure the mass of short-lived nuclei, applied to the 11Li case will be discussed. The experimantal angular distribution of the two halo-neutron transfer reaction 1H(11Li,9Li)t at 4.3A MeV, using the MAYA detector as a thin target, will be presented and compared to coupled reaction channel calculations including 3-body models in order to extract informations on the structure of the 11Li halo. The extraction of the 11Li+p optical potential using the data on the elastic scattering, will also be discussed. Finally, the excitation function of the resonant elastic scattering reaction, determined using the MAYA detector as a thick target, will be presented. Extraction of information on the structure of possible 12Li isobaric analog states observed in 12Be using several R-matrix calculations will be shown.

Active target MAYA, expérience TRIUMF; 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 S2n = 363(22) keV.

The p(\nuc{11}{Li},\nuc{9}{Li})t reaction has been studied for the first time at an incident energy of 3$A$ MeV delivered by the new ISAC-2 facility at TRIUMF. An active target detector MAYA, build at GANIL, was used for the measurement. The differential cross sectionshave been determined for transitions to the \nuc{9}{Li} ground andthe first excited states in a wide range of scattering angles. Multistep transfer calculations using different \nuc{11}{Li} model wave functions, shows that wave functions with strong correlations between the halo neutrons are the most successful in reproducing the observation., Comment: 6 pages, 3 figures, submitted to Physical Review Letters

The heavy-ion radiative capture reaction, 12C(12C,$\gamma$), has been investigated at energies both on- and off-resonance, with a particular focus on known resonances at Ec.m.=6.0, 6.8, 7.5, and 8.0 MeV. Gamma rays detected in a BGO scintillator array were recorded in coincidence with 24Mg residues at the focal plane of the DRAGON recoil separator at TRIUMF. In this manner, the relative strength of all decay pathways through excited states up to the particle threshold could be examined for the first time. Isovector M1 transitions are found to be a important component of the radiative capture from the Ec.m.=6.0 and 6.8 MeV resonances. Comparison with Monte Carlo simulations suggests that these resonances may have either J=0 or 2, with a preference for J=2. The higher energy resonances at Ec.m.=7.5 and 8.0 MeV have a rather different decay pattern. The former is a clear candidate for a J=4 resonance, whereas the latter has a dominant J=4 character superposed on a J=2 resonant component underneath. The relationship between these resonances and the well-known quasimolecular resonances as well as resonances in breakup and electrofission of 24Mg into two 12C nuclei are discussed.