the fair chance for nuclear astrophysics elemental abundances core-collapse supernovae the neutrino...
TRANSCRIPT
The FAIR Chance for Nuclear Astrophysics
• Elemental Abundances• Core-collapse Supernovae• The neutrino process• The r-process nuclei in -Wind • Neutron Stars in Binaries
100 m
UNILACSIS 18
SIS 100/300
HESR
SuperFRS
NESR
CR
RESR
GSI todayGSI todayFuture facilityFuture facility
ESR
FLAIR
Rare-IsotopeProduction Target
AntiprotonProduction Target
CBM
PP / AP
CN DE ES FI FR GB GR IN IT PL RO RU SE
Observers
100 m
UNILACSIS 18
SIS 100/300
HESR
SuperFRS
NESR
CR
RESR
GSI todayGSI todayNew facility FAIRNew facility FAIR
ESR
FLAIR
Rare-IsotopeProduction Target
AntiprotonProduction Target
CBM
PP / AP
Ion beams today:Z = 1 – 92(Protons til uranium)Up to 2 GeV/nucleon
Ion beams today:Z = 1 – 92(Protons til uranium)Up to 2 GeV/nucleon
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
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
FAIR Start Event: November 7, 2007
A splendid perspective and eminent challenge !
We are made of star stuffCarl Sagan
Each heavy atom in our body was build and processed through ~100-1000 star generations since the initial Big Bang event!
Signatures of Nucleosynthesis
• nucleosynthesis processes • nucleosynthesis history of our universe
solar abundance distribution
The stellar abundance distribution is a reflection of nuclear structure and nuclear stability!
The Cosmic Cycle
Evolution of a Star
Stellar Life
Simulation of Supernova Collapse
• Electron capture on nuclei
• Composition: increasingly neutron rich nuclei
• Elastic neutrino scattering on nuclei
Courtesy: RIKEN
Weak interaction during collapse phase
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
Courtesy Hans-Thomas Janka
Courtesy: Hans-Thomas Janka
Explosive Nucleosynthesis
• Neutrino-Proton Process (early ejecta, proton rich)• R-Process (late ejecta, neutron rich)
Neutrino reactions with nucleons determine the proton-to-neutronratio
Possible consequences of high neutrino flux in shock-front
Neutrino capture on protons1H(+,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
p-process in hydrogen rich, high neutron flux environments
On-site neutron production through neutrino induced interaction: 1H(+,e+)n!
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
Supernova shock front nucleosynthesis
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
Mass measurements at FAIR
FAIR Chance: Role of Halflives
• Competition velocity of ejected matter vs. halflives
• IF halflives were known, strong constraint of matter ejection from neutron star surface!
FAIR Chance: Neutron Stars
• Neutron Stars are laboratories for matter at extreme densities
• Neutron rich nuclei• Equation of State for
nuclear matter• Exotic phases?
X-Ray Burst and RP-Process
105g/cm3
106g/cm3
Ne
Si
C
1822
26
He6
10
14
2
Ar
Ti 30
34
4650
42
Sn
5458
6266
70 74Pd
Ignition
Fe
Zn38
Se
Sr
Mo
Waiting Points
End Point
Time [s]
100 200 300
Lu
min
os
ity
[e
rg/s
]
1
2
3
4
5 ·1038
AWmin
AWmax
0
= 106 g/cm3
Fate of ashes on neutron star surface
Neutron star surface
ashesocean
Innercrust
outercrust
H,He
gas
cooling
Radiativecooling
Nuclearreactions
thermonuclear
Electroncapture
thermonuclear
pycnonuclear
Increase with Z1Z2
superbursts
34Ne
1.5 x 1012 g/cm3
68Ca
1.8 x 1012 g/cm3
106Ge
56Ar2.5 x 1011 g/cm3
4.8 x 1011 g/cm3
72Ca 4.4 x 1012 g/cm3
rp-ashes
106Pd
56Fe
Ouellette, Gupta & Brown 2005Haensel & Zdunik 1990, 2003Beard & Wiescher 2003
Known mass
Crust processes
The FAIR Chance: New Horizons
The FAIR Chance: New Horizons