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The FAIR Chance for Nuclear Astrophysics. Elemental Abundances Core-collapse Supernovae The neutrino process The r-process nuclei in -Wind Neutron Stars in Binaries. Rare-Isotope Production Target. Antiproton Production Target. Observers.
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The FAIR Chance for NuclearAstrophysics • Elemental Abundances • Core-collapseSupernovae • The neutrino process • The r-process nuclei in -Wind • Neutron Stars in Binaries
Rare-Isotope Production Target Antiproton Production Target Observers CN DE ES FI FR GB GR IN IT PL RO RU SE SIS 100/300 GSI today Future facility SIS 18 UNILAC CBM ESR Super FRS HESR PP / AP FLAIR RESR CR NESR 100 m
Rare-Isotope Production Target Future beams: Intensity:primary ions 100-fold secondary RIB 10000-fold Types : Z =-1 – 92 (Antiprotons til uranium) Energies: ions up to 35 - 45 GeV/u antiprotons 0 -15 GeV/c Antiproton Production Target Ion beams today: Z = 1 – 92 (Protons til uranium) Up to 2 GeV/nucleon SIS 100/300 GSI today New facility FAIR SIS 18 UNILAC CBM ESR Super FRS HESR PP / AP FLAIR RESR CR NESR 100 m
FAIR Start Event: November 7, 2007 A splendid perspective and eminent challenge !
Each heavy atom in our body was build and processed through ~100-1000 star generations since the initial Big Bang event! We are made of star stuff Carl Sagan
Signatures of Nucleosynthesis solar abundance distribution • nucleosynthesis processes • nucleosynthesis history • of our universe The stellar abundance distribution is a reflection of nuclear structure and nuclear stability!
Simulation of Supernova Collapse • Electron capture on nuclei • Composition: increasingly neutron rich nuclei • Elastic neutrino scattering on nuclei Courtesy: RIKEN
Effects of Nuclear Electron Capture during Core Collapse The electron capture at high densities results in lower Ye and generates neutrino wind which is necessary for driving the shock. Hix, Messer, Mezzacappa, et al ‘03 Electron captures on nuclei dominate
Two-Dimensional Supernova Simulation • Plasma instabilities • Equation of State • Neutrino transport • Neutrino opacities • Dense matter correlations • Neutrino-nucleon reactions • Rotation, magnetic fields..... Courtesy: Hans-Thomas Janka Courtesy Hans-Thomas Janka courtesy
Explosive Nucleosynthesis Neutrino reactions with nucleons determine the proton-to-neutron ratio • Neutrino-Proton Process • (early ejecta, proton rich) • R-Process • (late ejecta, neutron rich)
Possible consequences of high neutrino flux in shock-front Neutrino capture on protons 1H(+,e+)n, neutron production which influence the reaction path by neutron capture. • Anti-neutrino capture on protons produce neutrons at late times • (n,p) reactions simulate beta decays and overcome waiting points
On-site neutron production through neutrino induced interaction: 1H(+,e+)n! p-process in hydrogen rich, high neutron flux environments By-passing waiting point nuclei 64Ge, 68Se by n-capture reactions.
The R-Process • Masses • Half lives • Neutron capture rates • Fission • Neutrino reactions Courtesy: K.-L. Kratz
R-Process Simulation Courtesy: Gabriel Martinez-Pinedo
FAIR Chance: Nuclear masses • R-Process abundances depend on neutron separation energies • Different mass models predict different patterns • FRDM: ‚robust‘ patterns, as observed in old halo stars in Milky Way • ETFSI: individual patterns strongly depending on neutron-to-seed ratios
Competition velocity of ejected matter vs. halflives IF halflives were known, strong constraint of matter ejection from neutron star surface! FAIR Chance: Role of Halflives
FAIR Chance: Neutron Stars • Neutron Stars are laboratories for matter at extreme densities • Neutron rich nuclei • Equation of State for nuclear matter • Exotic phases?
Neutron star surface Radiativecooling Nuclearreactions H,He gas thermonuclear ashes ocean thermonuclear outer crust Electroncapture Innercrust pycnonuclear n cooling Fate of ashes on neutron star surface
106Pd rp-ashes 4.8 x 1011 g/cm3 106Ge 56Fe 1.8 x 1012 g/cm3 68Ca Increase with Z1Z2 2.5 x 1011 g/cm3 72Ca 4.4 x 1012 g/cm3 56Ar 1.5 x 1012 g/cm3 34Ne Crust processes Ouellette, Gupta & Brown 2005 Haensel & Zdunik 1990, 2003 Beard & Wiescher 2003 Known mass superbursts