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Nupecc Meeting Catania, March 12, 2010 Activity at LNL and SPES L.Corradi Laboratori Nazionali di Legnaro – INFN, Italy.

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Presentation on theme: "Nupecc Meeting Catania, March 12, 2010 Activity at LNL and SPES L.Corradi Laboratori Nazionali di Legnaro – INFN, Italy."— Presentation transcript:

1 Nupecc Meeting Catania, March 12, 2010 Activity at LNL and SPES L.Corradi Laboratori Nazionali di Legnaro – INFN, Italy

2 The LNL The LNLaccelerators accelerators PIAVE HI Injector AN MV ALPI Linac 40 MVeq Tandem XTU 15 MV CN 7 MV

3 Open Calls for LoIs for the INFN research infrastructures May 2007 Open Calls for LoIs for the INFN research infrastructures May 2007 Transnational access E.Fioretto 50 LoIs 312 potential users from 15 countries (about 30% more than presented at the VI FP) 50 LoIs 312 potential users from 15 countries (about 30% more than presented at the VI FP)

4 Nuclear structure research Nuclear structure research AGATA demonstratorCLARAGASP - High spin states - Collectivity and shell model - Isospin symmetries - Isospin mixing in N=Z nuclei - Spectroscopy at the dripline - Shell stability and evolution in neutron rich nuclei - Symmetries at the critical point - Rotational damping - High spin states - Collectivity and shell model - Isospin symmetries - Isospin mixing in N=Z nuclei - Spectroscopy at the dripline - Shell stability and evolution in neutron rich nuclei - Symmetries at the critical point - Rotational damping

5 Reaction dynamics research Reaction dynamics research GARFIELD and 8πLP PRISMA and PISOLOEXOTIC -Multinucleon transfer - Nuclear superfluidity (pair transfer) - Elastic and inelastic scattering - Near and sub-barrier fusion -Multinucleon transfer - Nuclear superfluidity (pair transfer) - Elastic and inelastic scattering - Near and sub-barrier fusion - Multifragmentation at low excitation energies - Nuclear level density - Collective modes of excitations - Multifragmentation at low excitation energies - Nuclear level density - Collective modes of excitations - Break up processes - Quasi elastic scattering with light ions produced in secondary reactions - Break up processes - Quasi elastic scattering with light ions produced in secondary reactions

6 target MOT Fundamental interaction studies Fundamental interaction studies 18 O+ 197 Au trapped Fr isotopes 18 O beam I= 200 pnA I ~ 5x10 5 ions/sec the TRAPRAD experiment : production and trapping of Fr isotopes LNL-FE-SI collaboration Francium is the heaviest alkali, has a simple electronic structure and has enhanced P and T violation effects

7 % distribution of beam on target among the different set-ups % distribution of beam on target among the different set-ups LNL PAC Feb2010 LNL PAC Feb2006 average rejection factor for nuclear physics experiments over the last five years : 45-65%

8 5 asymmetric triple-clusters 36-fold segmented crystals 540 segments 555 digital-channels Eff. 3 – 7 M = 1 Eff. 2 – 4 M = 30 Full ACQ with on line PSA and -ray tracking Major issue (in the demonstration phase) is the Doppler correction capability coupling to beam and recoil tracking devices PRISMA D.Bazzacco Conventional array Segmented detectors -ray tracking Energy (keV) The innovative use of detectors (pulse shape analysis, -ray tracking, digital DAQ) will result in high efficiency (~40%) and excellent energy resolution Objective of the final R&D phase phase Objective of the final R&D phase phase The AGATA DEMONSTRATOR The AGATA DEMONSTRATOR

9 547 keV ( 197 Au) 847 keV ( 56 Fe) Dante+PSA 4.6 keV Original ~30 keV 56 Fe 197 Au 220 MeV Dante+PSA 2.6 keV Original ~10 keV Present set up: 3 triple clusters 4 th triple being installed now Present set up: 3 triple clusters 4 th triple being installed now Original and Doppler-corrected spectra for the 847 keV 56 Fe line Direction of recoils determined by the MCP Dante

10 neutrons protons Neutron drip-line Proton drip-line Spectroscopy and lifetimes in the new region of deformation n-rich A~60, N~40 nuclei n-rich nuclei Lifetimes in neutron- rich Ca isotopes N=50 shell gap: lifetime, and excited states Quenching of the N=82 shell gap in n-rich nuclei More than 20 LoI: Highly Excited Collective Modes. Proton-rich mirror nuclei. Superdeformed states in A~40 proton- rich region. Order-Chaos transition in warm rotating nuclei. etc... Evolution of collectivity and Dynamical Symmetries in the rare earths Mix-symmetry states Lifetimes in the region of the island of inversion Physics program : evolution of magic numbers and collectivity in neutron rich nuclei, but not only…

11 THE PRISMA SPECTROMETER + CLARA GAMMA ARRAY PRISMA:a large acceptance magnetic spectrometer 80 msr; B max = 1.2 Tm A/A ~ 1/200 Energy acceptance ~ ±20% INFN exp. PRISMA (LNL,PD,TO,Na) INFN exp. GAMMA (LNL,PD,Fi,MI,Na,Pg) + broad Int. Collaboration (UK,F,D,Pl,Sp,Ro,Hr)

12 Multineutron and multiproton transfer channels near closed-shell nuclei PRISMA spectrometer data GRAZING code calculations Mass [amu] pure neutron pick-up channels 90 Zr+ 208 Pb E lab =560 MeV L.Corradi et al, J.Phys G36(2009) (Topical Review)

13 Near- and sub-barrier fusion reactions Precise measurements of fusion excitation functions allow to probe nuclear structure effects: multi-dimentional tunnelling, influence of surface vibrations and transfer channels on reaction dynamics understand synthesis of superheavy elements measure rates of reactions of astrophysical interest A.M.Stefanini et al., PRC76(2007) cross section measurements at far sub- barrier energies may probe the nuclear potential inside the Coulomb barrier A.M.Stefanini et al PRC78(2008)044607

14 14 To do that we used the most neutron-rich stable beams available at the Tandem/PIAVE- ALPI accelerator complex of LNL at energies 5-15% above the Coulomb barrier 136 Xe 82 Se 70 Zn 64 Ni 36 S 26 Mg 22 Ne 48 Ca 40 Ar 96 Zr THE PRISMA + CLARA CAMPAIGN Grazing reactions as a tool to study n-rich nuclei

15 Cr (-4p) Gamma softness in heavy Cr and Fe isotopes populated in 64 Ni+ 238 U at E lab =404 MeV populated in 64 Ni+ 238 U at E lab =404 MeV Gamma softness in heavy Cr and Fe isotopes populated in 64 Ni+ 238 U at E lab =404 MeV populated in 64 Ni+ 238 U at E lab =404 MeV N.Marginean et al., Phys. Lett. B 633(2006) Cr New points The R(E 4 /E 2 ) ratio for the heavy Fe isotopes is very close to the 2.50 value characteristic of -soft rotors The value for the heavier Cr isotopes is also close to the same limit 58 Cr lies exactly at the 2.20 value predicted for the E(5) dynamical symmetry. The energies of the yrast band are in good agreement with the predictions of this symmetry. Transition probabilities are essential to decide whether 58 Cr lies or not at the E(5) critical point. dynamical symmetries

16 Lifetimes measurements in 48 Ca+ 208 Pb at E lab =310 MeV J.J.Valiente-Dobon et al, PRL102(2009) Differential Plunger Method comparison of deduced B(E2) with large scale shell model calculations

17 June 2011 LNL 6TC Dec 2011 GSI/FRS 8TC July 2013 GANIL/SPIRAL2 ~15TC AGATA D.+PRISMA AGATA + VAMOS + FRS Total Eff. > 10%Total Eff. > 20%Total Eff. ~6% AGATA Demonstrator/1Π Experimental program Experimental program AGATA Demonstrator/1Π Experimental program Experimental program

18 HECTOR: 8 Large BaF 2 High-energy -rays Coincident measurements +LCP MeV/A GARFIELD: 180 E- E telescopes Light Charged Particles PPAC or Phoswich Residues selection GARFIELD+HECTOR Campaign o Temperature dependence of GDR o Isospin Mixing of N=Z nucleus 80 Zr at high T o Dynamic Dipole in N/Z asymmetric reaction o Search for the Jacobi shape transition in light nuclei o Onset of the multi-fragmentation and the GDR F.Gramegna, A.Bracco et al, LNL-MI collaboration Nuclear structure at finite temperature

19 GARFIELD+HECTOR set-up – GDR studies in hot and thermalized nuclei : damping of collective modes at finite temperature nuclei : damping of collective modes at finite temperature GARFIELD+HECTOR set-up – GDR studies in hot and thermalized nuclei : damping of collective modes at finite temperature nuclei : damping of collective modes at finite temperature O. Wieland et al., PRL97(2006) Agreement with thermal fluctuation model if and only if CN evaporation width is included GDR analysis with no preequilibrium effects in 64 Ni+ 116 Sn Analysis of α particle spectra shows preequilibrium effects in 16 O+ 116 Sn Increase of GDR width is due to deformation effects Two reactions – same compound 16 O (130,250 MeV ) Sn 132 Ce* 64 Ni (300,400,500 MeV) + 68 Zn 132 Ce*

20 32 S MeV 300 μ500 μ Random impinging ions Be B C N O F Ne GARFIELD : studies of response of silicon detectors - channelling effects and digital pulse shape effects and digital pulse shape GARFIELD : studies of response of silicon detectors - channelling effects and digital pulse shape effects and digital pulse shape G.Poggi The FAZIA Initiative Final goal: build the full array for lower (SPIRAL2 / LNL / SPES) and higher energy (GANIL / LNS / FAIR / EURISOL / RIA) studies with exotic and stable beams. DIGITAL PULSE SHAPE on 500μm Silicon channelling spoils mass identification

21 Cyclotron 750 μA, 70 MeV (max) for protons in two exit ports: RIB - up to 300 μA p on UCx Application - up to 500 μA Cyclotron 750 μA, 70 MeV (max) for protons in two exit ports: RIB - up to 300 μA p on UCx Application - up to 500 μA Additional target station (special plants second priority) RIB or neutron production Additional target station (special plants second priority) RIB or neutron production UCx target station fission/s High Resolution Mass Spectrometer 1/20000 Charge Breeder 1+ n+ Charge Breeder 1+ n+ transport/beam cooler/separator (Post Accelerator ) SPES ISOL facility G.Prete

22 22 ALPI layout Optimum beta βo = βo = βo = 0.11 βo = 0.13 To be funded: 2 additional LowBeta Cryostats (CR1, CR2) a New buncher New magnetic lenses (upgrade from 20 to 30 T/m) Funded upgrade (2009) LowBeta CR3, new couplers ALPI upgrade for SPES

23 The ALPI post accelerator Superconductinglinac based on QW Resonators 2003: Up graded to Veq ~ 40 MV - Nb/Cu sputtered cavities or bulk Nb cavities; 2009: 48 MV Energies up to MeV/A for A=130 beams Expected SPES energies

24 ionization efficiencies: (1+) 30% and (n+) 4% (1+) 90% and (n+) 12% for Kr and Xe, Transport efficiency 50% Representative expected beams at SPES

25 Facility design First Target and ion source Second target and ion source Authorization to operate Building Tender & Construction Target installation and commissioning Cyclotron Tender & Construction Cyclotron Installation and commissioning Alpi preparation for post acceleration Installation of RIBs transfer lines and spectrometer Complete commissioning SPES SCHEDULE

26 SPES technical design report

27 Radioactive Beams LOI SPIRAL2 Dynamic Dipole in 172 Yb 5MeV/A (onset energy for DDR) Dynamical Dipole yield increases with asymmetry of fusing ions Dynamical Dipole Yields Baran, Brink, Colonna, DiToro PRL87(2001) S.Leoni Information can be extracted on the symmetry energy term at low density

28 proton stripping channels lead to neutron rich medium mass nuclei proton pick-up channels lead to neutron rich heavy mass nuclei

29 Multinucleon transfer reactions with neutron-rich beams possibility to populate nuclei via pick-up and stripping of both neutrons and protons probing (nn), (pp) and (np) correlations. Important for studies on pairing vibrations/rotations, nuclear superfluidity C.H.Dasso, G.Pollarolo, A.Winther, PRL73(1994)1907 GRAZING code calculations production of neutron rich isotopes

30 Near- and sub-barrier fusion reactions with exotic beams Key issues with RIB Enhanced effects of positive Q-value transfer channels Role of surface modes in nuclei with significant neutron excess With the lower beam intensities of RIB, one can derive fusion barrier distributions by measuring excitation functions of quasi-elastic channels F.Liang et al., PRC75(2007)054607S.Mitsuoka et al, PRL99(2007)182701

31 Some few remarks Nuclear structure and nuclear reactions with heavy ions are being investigated at near barrier energies with the TANDEM+ALPI+PIAVE accelerator complex of LNL Important developments have been made in complex detector systems (gamma arrays, tracking spectrometers, charge particle arrays) through which extensive studies have been and are being successfully performed in different areas The SPES project represents the most important step forward for nuclear physics research in Italy. Its completion will allow to perform challenging and significant studies in heavy ion physics with RIBs

32

33 SPES Primary Beam: Cyclotron 300 μA, 70 MeV (max) for protons in two exit ports for RIB Production Target: UCx multi-foil, up to fission s -1 Post-accelerator: PIAVE-ALPI Superconductive Linac up to 11 AMeV for A=130 Facility Approved for construction Phase 1 - financed by INFN LINAC ALPI TANDEM XTU Experimental HALLS RIB Transport Line III Experimental HALL The SPES project

34 Surface Ion source 12 HHe LiBeBCNOFNe NaMgAlSiPSClAr KCaScTiVCrMnFeCoNiCuZnGaGeAsSeBrKr RbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXe CsBaLaHfTaWReOsIrPtAuHgTlPbBiPoAtRn FrRaAcRfDbSgBhHsMt 8 Elements with bad volatility (NOT EXTRACTED) Surface Ionization Method Laser beam Laser Ion source Photo Ionization Method Ionization Method Plasma Ionization Method Main fission 238U fragments Plasma Ion source Ionization methods at SPES

35 The SPES target prototype Graphite Window UCx Disk Graphite Dumpers Graphite Box UCx emissivity SEM Characterization UCx target procuction SPES target-ion-source Front End

36 SPES expected neutron rich beams ElementMassMost Intense isotope (1/s) Ionization Eff (%) TargetIonization method R&D (difficulty) Ni UCxLIS** Cu UCxLIS** Zn UCxLIS** Ga UCxLIS** Ge UCxLIS*** Rb UCxSIS* Sr UCxSIS+LIS*** Y UCxLIS**** Pd UCxLIS**** Ag UCxLIS** Cd UCxLIS** In UCxSIS+LIS** Sn UCxLIS** Sb UCxLIS*** Te UCxLIS**** Cs UCxSIS* Ba UCxSIS+LIS*** La UCxSIS+LIS***

37 SPESSPES UNIPV UNIPDUNITN DIMDCTDEI DESIGNMATERIALS DIM Chemistr y CERN- ISOLDE GANIL-SPIRAL 2 ORSAY-ALTO TRIUMF- ISACORNL- HRIBF HANDLING CONTROLS SPES Target collaborations network KEK- TRIAC Pavia Milano LNS Bologn a DCT - Structure and Transportation Engineering DIM- Mechanical Eng. DEI- IT – Eng. Chemistry UNIPA LNL Nucl. Engin. Napoli Catani a Firenz e Padov a

38 38 SPES layout Present layout PIAVE cryostat ISACII-like cryostats PIAVE upgrade for SPES

39 GRAZING calculations Multinucleon transfer reactions are a promising tool to get access to very neutron rich heavy nuclei when using a neutron rich radioactive beam Eurisol Project (key experiments) Multinucleon transfer reactions in the transactinide region

40 Calculations : G.Pollarolo, Phys.Rev.Lett.100,252701(2008) Quasielastic barrier distributions : role of particle transfer channels Exp. data : S.Mitsuoka et al, Phys.Rev.Lett.99,182701(2007)

41 Dipole Resonance Emission from HOT nuclei t=0 fm/c fusion CN all degree of freedom EQUILIBRATED Giant Dipole Resonance Temperature dependence of GDR width damping of CN GDR p vs n Charge NOT equilibrated Prompt Dipole Reaction Dynamics EOS density plot dipole moment CNfusion

42 GARFIELD + HECTOR LNL Two reactions – same compound 16 O (130,250 MeV ) Sn 132 Ce* 64 Ni (300,400,500 MeV) + 68 Zn 132 Ce* pre equilibrium particle spectra GDR analysis with NO pre-equilibrium effects spectra

43 Last stage of the decay revealed by correlation functions Primary yields can be obtained after Coulomb background subtraction E*= 2.2, 4.3, 5.6 MeV E*=2.3, 3.5 MeVE*=0.7, 2.3 MeV d+ p+ 7 Be p+ 12 C

44 Experiments with n-rich/poor LNL 32 S+ 58 Ni and 32 S+ 64 Ni 14.5 AMeV GARFIELD & Ancillaries Pre-equilibrium emission in 16 O+ 116 Sn Measuring correlation functions R(q) probes space-time properties of source

45 Multinucleon transfer reactions : from neutron poor to neutron rich nuclei with (moderately n- rich) heavy ions one can populate (nn), (pp) and (np) channels with comparable strength GRAZING code calculations 44 Ar Pb E=320 MeV LNL data

46 Approaching 78 Ni and 132 Sn regions

47 Neutron rich nuclei produced in the fission of 238 U in 136 Xe+ 238 U at E lab =990 MeV 136 Xe+ 238 U at E lab =990 MeV Neutron rich nuclei produced in the fission of 238 U in 136 Xe+ 238 U at E lab =990 MeV 136 Xe+ 238 U at E lab =990 MeV N.Marginean et al., Phys. Rev. C80(2009)021301(R)

48 Total cross sections successive transfer S.Szilner et al, Phys.Rev.C76(2007)024604

49 IC MWPPAC A physical event is composed by the parameters: position at the entrance x, yposition at the entrance x, y position at the focal plane X, Yposition at the focal plane X, Y time of flight TOFtime of flight TOF energy DE, Eenergy DE, E A physical event is composed by the parameters: position at the entrance x, yposition at the entrance x, y position at the focal plane X, Yposition at the focal plane X, Y time of flight TOFtime of flight TOF energy DE, Eenergy DE, E PRISMA spectrometer – trajectory reconstruction

50 54 Cr 58 Fe 50 Ti most neutron-rich stable isotopes L.Corradi et al, Phys.Rev.C59(1999)261 possibility to make spectroscopic studies of neutron rich nuclei moderately far from stability Population of neutron rich nuclei 64 Ni+ 238 U at E lab =390 MeV

51 multinucleon transfer : experiment vs. theory multinucleon transfer : experiment vs. theory data : LNL theory : GRAZING code and CWKB L.Corradi et al, J.Phys.G36(2009) (Topical Review)

52 PRISMA beam direction 20 o 94,96 Zr 40 Ca Detection of (light) target like ions in inverse kinematics with PRISMA MNT channels have been measured down to 25 % below the Coulomb barrier L.Corradi et al, LNL exp. March 2009 Prisma acceptance

53 C.L.Jiang et al., PRC57(1998)2393 Detection of (light) target like ions in inverse kinematics with spectrographs Split Pole beam direction > 10 o 124 Sn 58 Ni H.Esbensen et al., PRC57(1998)2401 successive+direct pair transfer lacking of data for +2n in the deep sub-barrier region RMS data +1n +2n +3n

54 Comparison between experimental and theoretical (Grazing) calculations +1n +2n

55 Cr (-4p) Softness in Cr and Fe isotopes populated in 64 Ni+ 238 U at E lab =404 MeV gating on mass N.Marginean et al., Phys. Lett. B 633(2006)696 S.Lunardi et al., Phys. Rev. C 76(2007) Fe (-2p)

56 A schematic view of fusion reactions E σ EE σσ rrr VVV E << E b E ~ E b E > E b - σ steep fall off- fusion hindrance- CC effects nb - µb µb - mb ~ mb - structure of V N at r < r B - connection with astrophysics - D(B) from fusion and QE processes - connection with QF, MNT, DIC, BU - connection with surface vibrations and transfer - σ fusion < σ capture

57 Parity non conservation in atoms : a test of the Standard Model Precision tests of the SM at low momentum transfer complementary information obtained from atomic PNC and high energy electron-nucleon scattering experiments constraints on relevant new physics below certain mass scales

58 Parity non conservation in atoms : a test of the standard model important to pursue experimental work on chain of isotopes parity violation in specific atomic transitions nuclear anapole moment permanent electric dipole moment (time reversal symmetry violation) with 133 Cs reached precision below 1% with radioactive beams Francium is the heaviest alkali, has a simple electronic structure and has enhanced P and T violation effects


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