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

CRRESR

GSI today Future 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

CRRESR

GSI today New 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

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, 2007A 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

Lum

inos

ity

[erg

/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