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PRISMA-FIDES 2013-2016 Heavy-ion reactions from grazing collisions t o complete fusion. G.Montagnoli (100%), D.Montanari (100%), F.Scarlassara (50%) (Univ. and INFN - Padova) 2.5 FTE A.M. Stefanini (100%), L. Corradi (80%), E.Fioretto (100%), Huiming Jia (100%)
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PRISMA-FIDES 2013-2016 Heavy-ion reactions from grazing collisions to complete fusion G.Montagnoli (100%), D.Montanari (100%), F.Scarlassara (50%) (Univ. and INFN - Padova) 2.5 FTE A.M. Stefanini (100%), L. Corradi (80%), E.Fioretto (100%), Huiming Jia (100%) (INFN - LNL) 3.8 FTE G.Pollarolo (50%) (Univ. and INFN – Torino) 0.5 FTE 6.8 FTE overall • Joint work with the experiments EXOTICand GAMMA • Collaboration with GSI (D.Ackermann), Zagreb (S.Szilner,T.Mijatovic), Dubna (N.Kondratiev, R.Sagaidak), Strasbourg (F.Haas, S.Courtin), Cracow (J.Grebosz) July 2012
The PRISMA 2 experiment at LNL Traditionally, our group has always been involved in 2 lines of research: HI fusion reactions around VB presently focused at E << VB using the electrostatic beam separator PISOLO 2-body reactions pair transfer enhancement (transfer coupling to fusion n-rich isotope production ....) using the magnetic spectrometer PRISMA
PRISMA-2 • Heavy-ion reactions from grazing collisions to complete fusion: recent experiments on sub-barrier transfer and on fusion hindrance at very low energies • The AGATA demonstrator: nuclear structure of n-rich nuclei identified with PRISMA. At LNL until end of 2011. A small array of LaBr3:Cedetectors. • Heavy beams at LNL (Tandem, ALPI, PIAVE) and complementary experiments at other facilities (GANIL, ANL)
Detection of (light) target like ions in inverse kinematics with PRISMA beam direction PRISMA 20o 96Zr 40Ca Prisma acceptance Nucleon transfer channels have been measured down to 25 % below the Coulomb barrier
Sub-barrier transfer for 96Zr (beam) + 40Ca +1n well reproduced by theory in slope and absolute value Same slope of +2n between theory and experiment +2n enhancement due to the presence of other excited states? Absorption reproduced by theory 2n transfer to g.s. 2n transfer to 0+ (5,76MeV) (2n in p3/2) L. Corradi et al., Phys. Rev. C 84, 034603 (2011)
The experiment116Sn + 60Ni (Feb. 2012) Slopes for 116Sn + 60Ni Preliminary data Data under analysis +1n and +2n slopes are in agreement with those expected from binding energies PRELIMINARY P1 P2≈3(P1)2
LNL results on 58Ni + 54Fe Log slope Fus. x-sects. S-factor Ec.m. (MeV) A.M.Stefanini et al., PR C81, 037601 (2010)
Recent measurements on 40Ca+40Ca, 40Ca+48Ca and 48Ca+48Ca have investigated fusion hindrance and nuclear structure effects at sub-barrier energies (Fusion-evaporation residues detected using the electrostatic beam deflector at LNL) G.Montagnoli et al., PRC 85, 024607 (2012) C.L.Jiang et al., PRC 82, 041601(R) (2010) A.M.Stefanini et al., PLB 679, 95 (2009)
Our recent results on 32S + 48Ca by coupling schematically a Q>0 transfer channel, the data are well fit the barrier distribution is very wide and shows an unusual shape the logarithmic derivative is rather low and keeps increasing below the barrier
Study of nucleon-nucleon correlations (particle-vibration couplings, pairing vibrations, sub-barrier transfer) in binary reactions near the barrier • Couplings effects and fusion hindrance far below the barrier – fusion cross sections in light heavy-ion systems • Developments for Prisma: the new scattering chamber with a second TOF arm for kinematic coincidences, a new PPAC for light heavy-ions, better tracking of ion trajectories for higher A resolution • Test of γ-particle coincidences in Galileo and of the EXOTIC set-up for very low fusion x-sects. measurements • All this will allow us to use the future exotic SPES beams with great efficiency PRISMA-FIDES
Detection of coincident fragments (MCP,TOF,DE-E) Via high resolution kinematic coincidence we can also deduce the fission probability of associated heavy partners, determined as function of Z,A (light partner) and Q-value of the reaction Heavy partner : low Z,A resolution beam L.Corradi et al, Phys.Rev.C66(2002)024606 PRISMA Light partner : high Z,A resolution
Astrophysical S factors for several systemsmeasured in the last few years
Fusion of medium-light systems Measurements of very low fusion cross sections need high efficiency and low background. Tests using the EXOTIC line andg-particle coincidences with GALILEO are being considered
Investimenti II braccio Prisma (coinc. cinem.) Coinc. γ-particelle (in Galileo) Miglior. tracking
Previsioni di spesa 2013 - PD • Inventariabile: 56 k€ • Consumo: 26 k€ • Missioni estere: 6 k€ • Missioni interne: 5 k€ TOTALE : 93 k€ (per tutta la collaborazione circa 189 k€)
Richieste ai servizi LNL per il 2013 Richieste ai servizi Padova per il 2013
Sliding-seal scattering chamber Beam line Prisma Target Secondo Braccio
Electrostatic separator and E-ΔE-ToF telescope to detect evaporation residues at ≈ Oo scattering chamber MCP, IC & Si detectors beam E-ΔE-ToF telescope detecting ER HV _ _ + + target HV PAC-meeting 2008
1) July 31, 2011 to conclude the experimental campaign of PRISMA-AGATA measurements → AGATA stayed at LNL until December 2011- milestone reached 100% 2) December 15, 2011 to organize a measurement of sub-barrier transfer reactions involving superfluid nuclei → milestone reached 100% 3) June 30, 2012to perform the sub-barrier fusion experiment on Ca+Zr systems → milestone reached 80% 4) June 30, 2012to complete the installation of the new scattering chamber for PRISMA → milestone reached 30% 5) June 30, 2012to define the scientific program using PRISMA and Pisolo spectrometers for the next few years → milestone reached 100% 6) December 30, 2012 to complete the R&D studies of PRISMA upgradings for the next few years Milestones PRISMA-2 2011-2012
July 31, 2013 to extend the sub-barrier fusion experiments to medium-light systems • July 31, 2013 to study sub-barrier transfer in 92Mo+54Fe or in another proton-rich system • .Sep. 30, 2013 to install and test the new gas pumping and vacuum control of PISOLO • Dec. 20, 2013 to measure nucleon transfer channels in Ca+Ca systems • Dec. 20, 2013 to complete the tests of new detectors and DAQ upgrading for the second arm of PRISMA Milestones PRISMA-FIDES 2013
New sliding seal scattering chamber MCP + PPAC + IC? EFB EFB New large angle «coincidence arm»
Sub-barrier transfer for 96Zr (beam) + 40Ca L.Corradi et al., Phys. Rev. C84, 034603 (2011)