Thu·Apr 6, 2023Thursday·April 6, 2023

1. 01*

   Identification of medium mass (A=60-80) ejectiles from 15 MeV/nucleon peripheral heavy-ion collisions with the MAGNEX large-acceptance spectrometer

   G. A. Souliotis🇬🇷 · S. Koulouris🇬🇷 · F. Cappuzzello🇮🇹 · D. Carbone🇮🇹 · A. Pakou🇬🇷 · C. Agodi🇮🇹 · G. Brischetto🇮🇹 · S. Calabrese🇮🇹 · M. Cavallaro🇮🇹 · I. Ciraldo🇮🇹 · J. Klimo · O. Sgouros🇮🇹 and 4 other authors

   An approach to identify medium-mass ejectiles from peripheral heavy-ion reactions in the energy region of 15 MeV/nucleon is developed for data obtained with a large acceptance magnetic spectrometer. This spectrometer is equipped with a focal plane multidetector, providing position, angle, energy loss and residual energy of the ions along with measurement of the time-of-flight. Ion trajectory reconstruction is performed at high order and ion mass is obtained with a resolution of better than 1/150. For the unambiguous particle identification however, the reconstruction of both the atomic number Z and the ionic charge q of the ions is critical and it is suggested, within this work, to be performed prior to mass identification. The new proposed method was successfully applied to MAGNEX spectrometer data, for identifying neutron-rich ejectiles related to multinucleon transfer generated in the 70Zn+ 64Ni collision at 15 MeV/nucleon. This approach opens up the possibility of employing heavy-ion reactions with medium-mass beams below the Fermi energy (i.e., in the region 15-25 MeV/nucleon) in conjunction with large acceptance ray tracing spectrometers, first, to study the mechanism(s) of nucleon transfer in these reactions and, second, to produce and study very neutron-rich or even new nuclides in previously unexplored regions of the nuclear landscape.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2022)·12 citations
2. 02*

   Characterization of a gas detector prototype based on Thick-GEM for the MAGNEX focal plane detector

   I. Ciraldo🇮🇹 · G. A. Brischetto🇮🇹 · D. Torresi🇮🇹 · M. Cavallaro🇮🇹 · C. Agodi🇮🇹 · A. Boiano🇮🇹 · S. Calabrese🇮🇹 · F. Cappuzzello🇮🇹 · D. Carbone🇮🇹 · M. Cortesi🇺🇸 · F. Delaunay🇫🇷 · M. Fisichella🇮🇹 and 9 other authors

   A new gas detector prototype for the upgrade of the focal plane detector of the MAGNEX large-acceptance magnetic spectrometer has been developed and tested in view of the NUMEN project. It has been designed to operate at low gas pressure for detecting medium to heavy ions in the energy range between 15 and 60 AMeV. It is a drift chamber based on Multi-layer Thick-GEM (M-THGEM) as electron multiplication technology. Tests with two different M-THGEM layouts have been performed using both a radioactive $\alpha$-particle source and accelerated heavy-ion beams. The characterization of the detector in terms of measured currents that flow through the electrodes as a function of different parameters, including applied voltages, gas pressure and rate of incident particle, is described. The gain and ion backflow properties have been studied.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2023)·9 citations
3. 03*

   A+2n compound nuclei and the unitary limit in nuclear physics

   P. E. Georgoudis🇫🇷

   This contribution discusses a new perception of the structure of compound nuclei by introducing intermediate states of the Feshbach formalism of nuclear reactions in the Interacting Boson Model of nuclear structure. The stake is to explore the manifestation of the unitary limit in heavy, even-even nuclei. Interactions that govern Feshbach resonances of cold and dilute atomic gases suggest the formulation of an IBM-compound Hamiltonian for scattering two neutrons (2n) from a heavy, even-even target (A). The solutions of the corresponding coupled channel equations host a 2n-IBM state resonance. It turns out that the unitary limit is measurable in a heavy A+2n compound nucleus at low temperatures. That measurement is feasible through the fluctuations of the cross-sections that tune the 2n-A scattering length.

   ↳ nucl-thcond-mat.quant-gashep-phnucl-exJ.Phys.Conf.Ser.(2023)·1 citation

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.