Reaction dynamics and nuclear structure of moderately neutron-rich Ne isotopes by heavy ion reactions Simone Bottoni University of Milan & KU Leuven INPC Firenze

Outline Introduction to heavy ion reactions The PRISMA – CLARA experimental setup Reaction studies Nuclear structure studies Conclusions and perspectives Outline Simone Bottoni - University of Milan & KU Leuven

Heavy ion reactions Binary reactions a + A b + B Grazing impact parameter b g = R 1 + R 2 22 Ne MeV Introduction Simone Bottoni - University of Milan & KU Leuven

Theoretical models Semi- classical model (GRAZING) Inclusive calculations Elastic and transfer differential cross sections Macroscopic factor for internal excitation Microscopic factor for transfer processes DWBA model (PTOLEMY) Calculations for specific excited states Elastic, inelastic and transfer differential cross sections Microscopic calculations Deformation of excited states Introduction Simone Bottoni - University of Milan & KU Leuven

PRISMA CLARA Particle - γ coincidence measurements The PRISMA – CLARA experimental LNL ϑ g = 70° Simone Bottoni - University of Milan & KU Leuven

PRISMACLARA Optical elements: Magnetic quadrupole Magnetic dipole Detectors Entrance detector (MCP) Focal plane detector (PPAC) Inonization chamber (IC) ΔΩ ~ 80 msr ΔZ/Z ~ 1/60 ΔA/A ~ 1/ HpGe Clover ε ~3 E γ = 1.3 MeV Compton polarimeter 3 RINGS θ ~ 100°-130°-150° γ angular distributions Composite Ge 50mm x 70mm 2π BGO The PRISMA – CLARA experimental LNL Simone Bottoni - University of Milan & KU Leuven

22 Ne Z selectionCharge states selection 22 Ne (Z = 10) Data analysis – Ions identification Mass spectra Simone Bottoni - University of Milan & KU Leuven

Data analysis – Reaction studies Elastic cross section Normalization Inclusive cross sections GRAZING PRISMA CLARA ELASTIC DWBA fit Optical parameters Simone Bottoni - University of Milan & KU Leuven

Data analysis – spectroscopy Data analysis – γ spectroscopy γ spectra Doppler corrected event by event for v/c ≈ 10 % Simone Bottoni - University of Milan & KU Leuven

Data analysis – Reaction studies Inelastic cross sections 22 Ne MeV 24 Ne MeV GANIL DWBA Peak integration Q-value DWBA Simone Bottoni - University of Milan & KU Leuven

Data analysis – Nuclear structure studies Deformation parameters Closure of ν1d 5/2 in 24 Ne Sensitivity to β C Sensitivity to β N 24 Ne is a nucleus of key importance in the study of shell evolution towards the “island of invertion” Very old measurement! Simone Bottoni - University of Milan & KU Leuven

Conclusions Importance of heavy ion reactions for nuclear reaction and nuclear structure studies Effectiveness of magnetic spectrometers and Ge detectors combination (PRISMA – CLARA) Study of the reactions 22 Ne MeV Experimental analysis of particle angular distributions Comparison with theoretical models (GRAZING & PTOLEMY) Study of nuclear structure – evidence of strong reduction of β C in 24 Ne – additional investigations Perspectives: heavy ion reactions with exotic nuclei and a new generation of Ge detectors array of high efficiency (e.g. AGATA) Conclusions Simone Bottoni - University of Milan & KU Leuven

List of collaborators Collaboration Simone Bottoni - University of Milan & KU Leuven

Thank you for your attention Simone Bottoni - University of Milan & KU Leuven

EXTRA SLIDES Simone Bottoni - University of Milan & KU Leuven

The presorting of the data - PRISMA MCP calibration MWPPAC calibration 80x100 mm 1000x130 mm x res = 1 mm t res = 0.1 ns Ionization Chamber The ions pass by a Carbon foil generating secondary electrons which are accelerated toward an anode by an electric field. The anode is made of two orthogonal delay lines, respectively on the horizontal and vertical axis, which provide information on the position of the ions by calculating the difference in arrival time of the signals at the two ends of each delay line. Filling gas: CF4 Simone Bottoni - University of Milan & KU Leuven

BGO – antiCompton Add-back requirement The presorting of the data - CLARA Efficiency Energy Resolution Simone Bottoni - University of Milan & KU Leuven

The GRAZING code ION-ION POTENTIAL Semiclassical model GRAZING MACROSCOPIC factor for surface excitation whose form factor is proportional to the r-derivative of the ion-ion potential and whose strength is given by the experimental B(Eλ). [First quadrupole and octupole vibrations.] MICROSCOPIC factor for the exchange of nucleons which takes into account the single particle properties of the two colliding nuclei. The nucleus is described as an ensemble of independent nucleons that can vibrate around their spherical equilibrium shape. CLASSICAL orbits for relative motion and system of coupled equations for time evolution TRANSFER Simone Bottoni - University of Milan & KU Leuven

The PTOLEMY code DWBA model PTOLEMY The Distorted Wave Born Approximation PTOLEMY effective interaction for inelastic cross section OPTICAL potential OPTICAL parameters Simone Bottoni - University of Milan & KU Leuven

Deformation 22 Ne MeV – Oak Ridge 20 Ne MeV - Oak Ridge CC analysis 26 Ne+ nat 1.4 GeV - Rikken CC analysis 18 Ne GeV – MSU CC analysis 22 Ne 2.9 MeV – Palo Alto DSAM 28 Ne+ nat 1.3 GeV - Rikken CC analysis 22 Ne+ Nat Ni – Isolde Coul.Ex. Adopted values : S. Raman, C.W. Nestor jr., P. Tikkanen, At. Data Nucl. Data Tables 78, 1 (2001). Simone Bottoni - University of Milan & KU Leuven