Experiments with Radioactive Beams at GSI and FAIR Thomas Aumann May 21st, th INTERNATIONAL SPRING SEMINAR ON NUCLEAR PHYSICS NEW QUESTS IN NUCLEAR STRUCTURE VIETRI SUL MARE * Modularized start version of FAIR - NuSTAR science with modules 0 to 3 - What is missing - Conclusion * Physics program on the way to FAIR Example: Quasifree scattering at R3B Single-particle structure of nuclei an N-N correlations

FAIR Modularized Start Version Cost: 1027 M€ Available: 1039 M€ 104 M€ 19 M€ Modules 4 and 5 will be implemented as additional funds become available!

FAIR Modularized Start Version Significant cost increases in civil construction and site development cost (  Germany pays additional 95 M€ for site specific costs) Modularized Start Version of FAIR A defined in White Paper Draft –Module 0: Heavy-Ion Synchrotron SIS100 –Module 1: Experiment hall at SIS100 for beam diagnostics, HADES/CBM, APPA, and detector calibration. –Module 2: Super-FRS for NUSTAR including all three branches and the energy buncher –Module 3: Antiproton facility for PANDA (LINAC; target, CR, HESR) and CR also for NuSTAR –Module 4: LEB cave, NESR storage ring for NUSTAR und APPA, FLAIR building, cave for APPA –Module 5: RESR storage ring for a higher beam intensity for PANDA and parallel operation with NUSTAR Cost : M€ (2005) using updated civil construction cost and cost book values (CB 5.0) for accelerators Accepted available funds amount to M€ (2005) –another 62 M€ not firm + 12 M€ from Saudi Arabia (new partner) Construction schedule foresees readiness for installation end 2016

Implementation Scenario for NuSTAR Experiments in Modules 0-3 R3B DESPEC at MF-4 ?? HISPEC At LEB focus?? MATS & LASPEC behind R3B ?? ILIMA in CR

NuSTAR Experiments Modules 0-3 ILIMA Isochronous mode shortest-lived nuclei limited precision R3B full capability DESPEC full capability HISPEC full capability MATS & LASPEC full capability Delays possible for EXL in NESR (Module 4) ILIMA in NESR (Module 4) ELISe (FAIR B) (+ building for energy buncher)

R 3 B: reaction studies at the highest energies in complete kinematics  full R 3 B programme will be accessible (world-wide unique) –few body correlations at and beyond the drip-lines in break-up reactions (halo nuclei, open quantum systems) –dipole response below and above the particle threshold using Coulomb excitation and breakup (Pygmy response, neutron skins, neutron matter properties, EOS) –Evolution of shell structure and single-particle occupancies using knock-out and quasi-free scattering experiments (tensor force, shell quenching) –Nuclear dynamics in fission and the symmetry energy at supra-saturation density in fragmentation reactions (large scale collective motion EOS) –Measurement of (gamma,n) reaction rates for r-process nuclei (origin of the heavy element) NuSTAR science within Modules

DESPEC: decay spectroscopy using gamma-ray and neutron spectroscopy following isomeric or beta-decay of very exotic nuclei Experiments with production rates between 1000 per second and 1 per hour possible (  farthest reach towards the drip lines) –Measurement of absolute Gamow Teller strength values –Investigations of 100 Sn and nuclei along/beyond the proton dripline –Structure of nuclei in heavy r-process region –Measurement of g-factors of isomeric states and half lives of very short isomers

NuSTAR science within Modules HISPEC: high resolution in-flight gamma-spectroscopy (HISPEC with AGATA) –Probing the evolution of nuclear shell structure in very n-rich medium-heavy nuclei using Coulomb-excitation, knock-out, and secondary fragmentation –Probing the evolution of nuclear collectivity far from stability using Coulomb- excitation, lifetime and g-factor measurements

NuSTAR science within Modules MATS and LASPEC: precision masses, ground-state moments short-lived nuclei and refractory elements not available with ISOL using ion-traps and laser spectroscopy after gas-stopping cell

NuSTAR science within Modules ILIMA in CR: direct mass measurements of nuclei with half-lives in the millisecond region (most exotic, r-process) half-life experiments on highly-charged exotic ions studies of long-lived isomeric states. Highlight: Half-lives and masses of r-process nuclei responsible for the A~195 abundance mass peak

What is missing? NESR ILIMA: precise masses and half-lives of many nuclei unique decay modes ELISe: Elastic and inelastic electron scattering (charge distributions, giant resonances) EXL: Elastic scattering and low-q reactions (matter distributions, monople resonances, capture reactions, trnasfer, knock-out) Experiments with stored electron cooled ion beams World-wide unique Conceptionaly new AIC: Antiproton anihilation on nuclear surface (neutron skin thickness)

Conclusions Modules of FAIR will allow for unique, exciting, and world-unique experiments Modularized FAIR start version is an essential step towards establishing the FAIR GmbH However: NuSTAR experimental programme will bring to fruition only a fraction of its full potential  Need for NESR with world-wide unique experimental  Need RESR for availability of parallel beams at FAIR  Need SIS300 for full multi-user capabilities and maximum efficiency of FAIR facility  We need to continue to work towards the full FAIR facility!!  Continue to work on TDRs for NuSTAR experiments  Continue a vigorous program at GSI FRS and ESR

Deviation from the independent-particle picture: Correlations: Configuration mixing, Coupling to collective phonons Short-range correlations → high momenta → reduced single-particle strength (occupations, spectroscopic factors) The nucleus: single-particle motion in a mean field ? Ingo Sick

Spectroscopic factors for neutron-proton asymmetric nuclei Figure from Alexandra Gade, Phys. Rev. C 77, (2008) Comparison e- induced knockout and knockout in inverse kinematics with light target (Be)

Spectroscopic factors for neutron-proton asymmetric nuclei weakly bound nucleons Figure from Alexandra Gade, Phys. Rev. C 77, (2008)

Spectroscopic factors for neutron-proton asymmetric nuclei strongly bound nucleons ? Origin unclear isospin dependence of correlations ? Figure from Alexandra Gade, Phys. Rev. C 77, (2008) weakly bound nucleons

Correlations in asymmetric nuclei and nuclear matter Subedi et al. protons neutrons ρ = 0.32 fm −3 ρ = 0.16 fm −3 Electron-induced knockout (JLab)

Sensitivity of Coulomb and nuclear breakup Reaction probabilities Coulomb breakup Overlap with continuum wave function Halo-Neutron Densities Sensitivity to the tail of the wave function only Alternative approach: quasi-free scattering: (p,2p), (p,pn) etc. at LAND and R3B or (e,e'p) at the e-A collider at FAIR Nuclear breakup

Future: Quasi-free scattering in inverse kinematics kinematical complete measurement of (p,pn), (p,2p), (p,pd), (p,a),.... reactions redundant experimental information: kinematical reconstruction from proton momenta plus gamma rays, recoil momentum, invariant mass sensitivity not limited to surface → spectral functions → knockout from deeply bound states cluster knockout reactions Measurement of proton recoils after knockout reactions with a CH 2 target x,  E proton CsI, NaI Si, strip CH2 target projectile Z,A B n,p,...

Experimental Setup: C Beam Target box of DSSDs for proton tracking polar angle coverage ≈ 15°≤  ≤ 80° resolution:  x ~ 100  m;  E ~ 50 keV range: 100 keV < E < 14 MeV Crystal Ball detector cm long NaI(Tl) crystals additional low gain readout of forward 64 crystals 4  gammas 2  light particles “New” Target Recoil Detector for Quasifree Scattering

Experimental Setup: C Beam Target box of DSSDs for proton tracking polar angle coverage ≈ 15°≤  ≤ 80° resolution:  x ~ 100  m;  E ~ 50 keV range: 100 keV < E < 14 MeV Crystal Ball detector cm long NaI(Tl) crystals additional low gain readout of forward 64 crystals 4  gammas 2  light particles “New” Target Recoil Detector for Quasifree Scattering

Quasifree Scattering with Exotic Nuclei: 17 Ne(p,2p) 15 O+p The two-proton Halo (?) nucleus 17 Ne Nucleus of interestExcited Fragment A A-1 Free Target Proton Recoil q Photon(s) Bound Proton Separation EnergyInternal Momentum q p,n,d,t,... Evaporation Scattered Protons:  opposite  angles opening angle  90° Pilot experiments with 12 C, 17 Ne and Ni isotopes already performed at the LAND-R3B setup are under analysis … Angular Correlations measured with Si-strip detectors for 17 Ne(p,2p) 15 O+p  ~180°,  ~83° (sim. as for free pp scattering)

Gamma Spectrum in Coincidence with 12 C(p,2p) 11 B Reaction Channel M. Yosoi, PhD Thesis, 2003, Kyoto University preliminary EγEγ (MeV) Counts inverse kinematics gamma spectrum after p knockout s proton knockout energy spectrum from invariant mass analysis V. Panin et al.

Quasi-free cluster knockout L. Chulkov et al., NPA 759(2005) 43 6 He + p →  + p' + X Momentum distribution Experiment S174: Proton elastic scattering (P. Egelhof et al.) Spectroscopic factors: neutron: 1.7(2) alpha: 0.8(1)