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Corradi, L., Szilner, S., Pollarolo, G., Colo, G., Mason, P., Farnea, E., et al. (2011). Single and pair neutron transfers at sub-barrier energies. Phys. Rev. C, 84(3), 034603–10pp.
Abstract: Multinucleon transfer cross sections in the (96)Zr+(40)Ca system have been measured, in inverse kinematics, at bombarding energies ranging from the Coulomb barrier to similar to 25% below. Targetlike recoils have been identified in A, Z and velocity with the large solid angle magnetic spectrometer PRISMA. The experimental data for one- and two-neutron transfer channels have been compared with semiclassical microscopic calculations. For the two-neutron transfer channels the relevance of the transitions to the ground state and to the 0(+) excited states of (42)Ca are discussed by employing, for the reaction mechanism, the successive approximation. It is found that the transition to the 0(+) state at similar to 6 MeV, whose wave function is dominated by the two neutrons in the 2p(3/2) shell, is much larger than the ground state one. The comparison with the inclusive data reveals that transitions to states with high multipolarity and non-natural parity are important. This suggests that more complex two-particle correlations have to be incorporated in the treatment of the transfer process.
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Jaworski, G., Palacz, M., Nyberg, J., de Angelis, G., de France, G., Di Nitto, A., et al. (2012). Monte Carlo simulation of a single detector unit for the neutron detector array NEDA. Nucl. Instrum. Methods Phys. Res. A, 673, 64–72.
Abstract: A study of the dimensions and performance of a single detector of the future neutron detector array NEDA was performed by means of Monte Carlo simulations, using GEANT4. Two different liquid scintillators were evaluated: the hydrogen based BC501A and the deuterated BC537. The efficiency and the probability that one neutron will trigger a signal in more than one detector were investigated as a function of the detector size. The simulations were validated comparing the results to experimental measurements performed with two existing neutron detectors, with different geometries, based on the liquid scintillator BC501.
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Goasduff, A., Valiente-Dobon, J. J., Lunardi, S., Haas, F., Gadea, A., de Angelis, G., et al. (2014). Counting rate measurements for lifetime experiments using the RDDS method with the new generation gamma-ray array AGATA. Nucl. Instrum. Methods Phys. Res. A, 758, 1–3.
Abstract: The differential Recoil Distance Doppler Shift (RDDS) method after multinucleon transfer (MNT) reactions to measure lifetimes of excited states in neutron-rich nuclei requires the use of a thick energy degrader for the recoiling ejectiles that are then detected in a spectrometer. This type of measurements greatly benefits from the use of the new generation segmented gamma-ray detectors, such as the AGATA demonstrator which offers unprecedented energy and angular resolutions. In order to make an optimized choice of the material and the thickness of the degrader for lifetime measurements using the RODS method after MNT, an experiment has been performed with the AGATA demonstrator. Counting rate measurements for different degraders are presented.
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Mengoni, D., Duenas, J. A., Assie, M., Boiano, C., John, P. R., Aliaga, R. J., et al. (2014). Digital pulse-shape analysis with a TRACE early silicon prototype. Nucl. Instrum. Methods Phys. Res. A, 764, 241–246.
Abstract: A highly segmented silicon-pad detector prototype has been tested to explore the performance of the digital pulse shape analysis in the discrimination of the particles reaching the silicon detector. For the first time a 200 tun thin silicon detector, grown using an ordinary floating zone technique, has been shown to exhibit a level discrimination thanks to the fine segmentation. Light-charged particles down to few MeV have been separated, including their punch-through. A coaxial HPGe detector in time coincidence has further confirmed the quality of the particle discrimination.
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Modamio, V., Valiente-Dobon, J. J., Jaworski, G., Huyuk, T., Triossi, A., Egea, J., et al. (2015). Digital pulse-timing technique for the neutron detector array NEDA. Nucl. Instrum. Methods Phys. Res. A, 775, 71–76.
Abstract: A new digital pulse-timing algorithm, to be used with the future neutron detector array NEDA, has been developed and tested. The time resolution of four 5 in diameter photomultiplier tubes (XP4512, R4144, R11833-100, and ET9390-kb), coupled to a cylindrical 5 in by 5 in BC501A liquict scintillator detector was measured by employing digital sampling electronics and a constant fraction discriminator (CFD) algorithm. The zero crossing of the CM algorithm was obtained with a cubic spline interpolation, which was continuous up to the second derivative. The performance of the algorithm was studied at sampling rates of 500 MS/s and 200 MS/s. The time resolution obtained with the digital electronics was compared to the values acquired with a standard analog CFD. The result of this comparison shows that the time resolution from the analog and the digital measurements at 500 MS/s and at 200 MS/s are within 15% for all the tested photomultiplier tubes.
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