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Wide spectrum of pure radioactive ion beams Energy: from ~ rest up to 3 MeV /u

Wide spectrum of pure radioactive ion beams Energy: from ~ rest up to 3 MeV /u. Post accelerated beams: 8,9,11 Li, 10-12 Be, 10 C, 17 F, 24-29 Na, 28-32 Mg, 61,62 Mn, 61 Fe, 68 Ni, 67-71,73 Cu, 74,76,78,80 Zn, 70 Se, 88,92 Kr, 96 Sr, 108 In, 106,108,110 Sn,

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Wide spectrum of pure radioactive ion beams Energy: from ~ rest up to 3 MeV /u

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  1. Wide spectrum of pure radioactive ion beams • Energy: from ~ rest up to 3 MeV/u • Post accelerated beams: • 8,9,11Li, 10-12Be, 10C, 17F, • 24-29Na, 28-32Mg, 61,62Mn, • 61Fe, 68Ni, 67-71,73Cu, • 74,76,78,80Zn, 70Se, 88,92Kr, • 96Sr, 108In,106,108,110Sn, • 122,124,126Cd,138,140,142,144Xe, 140,142,148Ba,148Pm, 153Sm, • 156Eu, 182,184,186,188Hg, 202,204Rn • The energies available at REX-ISOLDE are optimal to exploit Coulomb Excitation and Transfer reactions

  2. The techniques: Coulomb Excitation Nuclear excitation by the electromagnetic interaction acting between two colliding nuclei. Target and projectile excitation possible “ Safe” Energy Requirements Coulomb trajectories only if the colliding nuclei do not reach the “Coulomb barrier” “SAFE” Coulomb Excitation:purely electromagnetic process, NO nuclear interaction, calculable with high precision The Coulomb Excitation cross-sections are a direct measurement of the matrix elements involved in the excitation Spectroscopic tool to study single-particle versus collective properties of nuclei • High selectivity to (1) transition with E2 transitions most probable, • (2) collectivity • Typical reactions: heavy, closed-shell target Observables • energies of g-rays • Momentum of projectile and recoil target (Doppler shift correction) • Absolute Excitation cross-section normalized to the known target excitation

  3. The techniques: Transfer Reaction Spectroscopic tool to study single-particle properties of nuclei • selectivity to (1) kinematical matching (e.g. Qopt = 0 for n-transfer) • (2) nuclear structure Typical reactions: (d,p), (t,p) … RIBs: inverse kinematics Observables • energies of protons (+ Eg) è(single-particle) level energies • angular distributions of protons (+ g-rays) èspin/parity assignments • (relative) spectroscopic factors è particle configurations p g-decay d … both, successful tool in nuclear spectroscopy for more than 50 years!!!

  4. The MINIBALL detector array • MAIN CHARACTERISTIC • 8 Miniball clusters • Each cluster: 3 HPGe crystals • Each crystal: 6-fold segmented • 8% efficiency @ 1.3 MeV München, Köln, Heidelberg, Darmstadt, Leuven, York, Liverpool, Daresbury, Strasbourg,...

  5. “Safe” Coulomb Excitation experiments • Particle (CD) – γ correlations CD – detector Double sided Si strip detector Miniball • Particle ID in a Double-Sided Si Strip Detector • Event by event Doppler correction • 17° < lab< 54° PPAC REX- ISOLDE Target ( 1-2 mg/cm2)

  6. Data Analysis • Event by event Doppler correction • Absolute Cross Sections are determined by normalizing to the known target excitation • CLX code or GOSIA code to extract the transitional matrix elements 70Cu 127 keV Doppler Corrected for Projectile Projectile 70Cu 511 keV Target Doppler Corrected for target 120Sn 1171 keV

  7. T-REX … Si detector array for Transfer experiments at REX-ISOLDE Miniball beam beam Some data • large solid angle (58% of 4p) • position sensitive • PID (DE-E): p, d, t, a, • … and e- from b-decay (!) • Technical details: • Barrel: 140 mm DE / 16 resistive strips • 1000 mm E / pad • Backward CD: 500 mm DE / DSSSD • 500 mm E / pad (funded by TU München, KU Leuven, U Edinburgh, CSNSM Orsay, TU Darmstadt)

  8. The Island of Inversion 30Mg(t,p)32Mg • Identifying and characterizing the excited 0+ in 32Mg • Tritium-implanted Ti foil 3H 40 μg/cm2,Activity 10 GBq • 30Mg at 1.8 MeV/nucleon, 4.6x104pps coexistence of spherical and deformed states deformed 2p−2h configuration becomes ground state in 32Mg where is the excited 0+ state?

  9. The REX-ISOLDE - MINIBALL physics program: Structure and Shapes • Towards the doubly magic 100Sn • (Lund, CERN) • Mixed symmetry states in 88Kr • (Warsaw) • g-factors in Te isotopes • (Bonn) • Shape coexistence in 70Se • (Liverpool) • B(E2) measurements around 132Sn • (Munich) • Stellar reaction • 14O(a,p)17F • (Edinburgh) • Towards the doubly magic 78Ni (Leuven) • N=40: Coulex of 68Ni and 68,70,m,gCu (CERN, Leuven) • “Island of inversion at N=20” (Heidelberg) • Fusion reactions with neutron-rich nuclei (Köln) • Neutron transfer reactions on 30Mg (Darmstadt)

  10. Outlook and short and intermediate term • ENERGY: • Energy upgrade(Coulex and transfer): 3.1  5  10 MeV/u • INTENSITY: ISOLDE proton driver beam intensity upgrade • strongly linked to PS Booster improvements including linac4 • QUALITY: ISOLDE radioactive ion beam quality: continuous developments for broader spectrum and higher quality (purity, emittance,time structure) and isomeric beams ISOLDE has a unique potential and combines unique capabilities: beams (pure, isomeric), techniques and instrumentation • NEW INSTRUMENTATION: • HELIOS, ACTAR • New set-up for transfer reactions • Recoil spectrometer (identification of the reaction products)

  11. Helios • Solenoid for transfer reactions • Improves particle resolution with respect to T-REX but no gamma detection • Needs buncher/chopper for TOF measurement with 2 ns resolution • Currently operating at ANL; UK proposal to build a new version

  12. ACTAR • Active target for resonant scattering and transfer reactions • Allows to measure with very low intensities • MAYA operational at GANIL and in ISOLDE in 2012 • Would benefit from slow extraction • New electronics (GET) being developed

  13. Fusion Evaporation, Fragmentation, Fission T1/2 AY Capture reactions Radioactive Decay Deep inelastic scattering see M. Borge, A. Jokinen Few nucleon transfer see Th. Nilsson Coulomb excitation A-1X (e.g. d,p) AX Oak-Ridge - GANIL - GSI - MSU - RIKEN - TRIUMF -LLN • Energy • Spin and Parity • Decay Strength Distributions • E.M.-Transition Matrix Elements • Spectroscopic Factors • Shapes and Moments Radioactive Ion Beams

  14. The Belgian Research Initiative on eXotic nuclei (BriX) (2007-2011) • Physics n-induced and beta-delayed fission N=82 Z=82 Shape coexistence along Z=82 N=50 N=40 Nuclear structure along the N=Z line Z=50 Fundamental interaction studies Z Z=28 Towards 78Ni: shell structure along Z=28 and N=50 N “Island of inversion around 32Mg” Feasibility study for ISOL@MYRRHA Structure of light exotic nuclei 20

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