Open questions and issues in nuclear astrophysics

1
Open questions and issues in nuclear astrophysics
And the role of EURISOL.

• Kerstin Sonnabend
• Darmstadt, Germany
• Presented by
• Michael Hass, Weizmann, Israel

2
CARINAChallenges and Advanced Research In
Nuclear Astrophysics
Carmen Angulo

• Kerstin Sonnabend
• Institut für Kernphysik, TU Darmstadt, Germany

3
CARINA activities

• Two CARINA workshops organized
• First workshop Perspectives in European Nuclear
  Astrophysics, Parador dAiguablava, Girona,
  Spain, June 8th - 10th, 2005
• 39 participants from ten countries
• five review talks on astrophysical models
  (explosive burning and AGB/quiescent burning),
  nuclear models for astrophysics, experiments with
  RIB at LSF, and experiments at small facilities
• short talks and discussions in working group
  sessions (plenary)
• summary of the conclusions
• large variety of problems needs large variety of
  methods
• specific tools needed for different
  nucleosynthesis scenarios
• small-scale facilities as feeders to
  large-scale facilities
• establish a flagship ISOL-type facility for
  nuclear astrophysics with gas targets, recoil
  separator, spectrometer, solid-state detectors,
  and g-ray detection systems available
• find tentative lists of astrophysical sites and
  nuclear models for nuclear astrophysics

4
CARINA activities

• Second workshop Frontier Research in European
  Nuclear Astrophysics, Spaulomont, Spa, Belgium,
  April 25th - 28th, 2007
• 37 participants from 13 countries
• 21 talks and five discussions (plenary)
• workshop explored opportunities for new European
  facilities
• agreement that additional facilities,
  specifically for nuclear astrophysics, are
  warranted and needed
• lively discussion over strategy should it be a
  dedicated nuclear astrophysics proposal, or
  complementary to a general nuclear physics
  proposal?
• possibilities include nuclear astrophysics labs
  network, an underground accelerator, a dedicated
  nuclear astrophysics separator for capture
  reactions, reclamation of radioisotopes, ...

5
Continuation of the CARINA network within FP7

• JRA-9 (P.J. Woods M. Hass)
• NA-15 (S. Marrone F. Käppeler)
• NA-16 (K. Sonnabend C. Angulo)
• and tasks of N-NA07 (Theory) related to Nuclear
  Astrophysics

6
N-NA06Nuclear Astrophysics

• Coordinator K. Sonnabend, Darmstadt, Germany
• Task 1 Explosive Nucleo-Synthesis
• P.J. Woods, Edinburgh, UK, M. Hass,
  Weizmann, Israel
• Task 2 - Reactions at Low Temperatures
• K. Sonnabend, Darmstadt, Germany
• Task 3 - Nucleo-Synthesis in neutron capture
  processes
• S. Marrone, INFN Bari, Italy
• Task 4 Nuclear astrophysics annual meeting

ENSAR meeting, Frankfurt, December 12th, 2007
7
Novelty Innovation

• Concentrate on special issues of
  interdisciplinary field of research
• Provide individual solutions for problems of
  special issues
• Use already available infrastructures
• Find and enhance synergetic effects
• Integrate it all in annual meetings

8
Task 2 - Reactions at Low Temperatures K.
Sonnabend, Darmstadt, Germany

• e.g. - Solar reactions
• Not necessarily RIB
• Smaller laboratories (local)
• Underground possibilities (a la LUNA)

9
The SNO (Sudbury Neutrino Observatory) Experiment
A D2O Detector
Elastic Mostly ne
nx e- nxe-
ne d p p e- charge current
Only ne
nx d p n nx neutral current
All flavors
YES!! PRL 87, 071301 (2001) PRL 89, 011301
(2002) PRL 92, 181301 (2004)
SMOKING GUN!!
10
Current status of S17 - direct capture -
determinations
Recognized need for a new WI measurement at low
energy In progress 7Be(p,g)8B saga not over
yet..
11
Summary of Coulomb Dissociation S17 Results
F. Schümann et al. Phys. Rev. C 73, 015806 (2006)
By Courtesy of T. Motobayashi
12
S17 astrophysical factor - ANC - (R. Tribble)
Transfer
Determine C2 by three approaches
8B breakup

• JLM S1717.42.1 eVb
• standard S1719.61.2 eVb
• Ray S1720.01.6 eVb

Average S1718.71.9 eVb
PRC 04
13
Results and Fits
New LUNA Activity Result
- Phys. Rev. Lett. 97, 122502 (2006)
S34(0) 0.53(2)(1) keV-b B.S. Nara Singh et
al., Phys. Rev. Lett. 93, 262503 (2004).
No compelling need to assume Systematic
difference between prompt and activity
determinations

• RMS ERNA in Bochum
• Seattle

14
Dedicated experiments to measure the 7Be EC
lines Borexino etc
SNO
15
b.- Primordial 7Li SBBN (A. Coc, Orsay)
16
n_TOF/Astrophysicspresent future
Task 3 - Nucleo-Synthesis in neutron capture
processes S. Marrone, INFN Bari, Italy
stefano.marrone_at_ba.infn.it
www.cern.ch/n_TOF
17
Nuclear Astrophysics
Re/Os cosmo-chronometer
Red Giants
Nr Nsolar Ns Residual Method
Supernovae
stefano.marrone_at_ba.infn.it
www.cern.ch/n_TOF
18
The n_TOF-Ph2 experiments 2008 and beyond
() endorsed by CERN Isolde-n_TOF Committee,
execution in 2008
stefano.marrone_at_ba.infn.it
www.cern.ch/n_TOF
19
The second n_TOF beam line
NewExperimentalArea (EAR-2)
20 m
present EAR-1 (at 185 m)
Proton Beam
Spallation Target

• present EAR-1 Flight path 185 m, Neutron
  Flux106 n per proton bunch High resolution in
  neutron energy.
• new EAR-2 Flight path 20 m at 90 with respect
  to p-beam neutron flux enhanced by factor 100
  drastic reduction of backgrounds.

stefano.marrone_at_ba.infn.it
www.cern.ch/n_TOF
20

• Task 1 Explosive Nucleo-Synthesis

• Identification of the key reactions, including
  specification of the energy range and
• precision required for future experimental
  studies (leading institute Barcelona).
• Identification of the key technical developments
  required to deliver the highest
• priority radioactive beams to measure these
  reactions including exchange of
• technical ideas and coordination, of how and
  where developments should be
• best achieved (leading institute Weizmann).
• Identification of the key characteristics of
  design and construction of
• novel detector and spectrometer systems to
  measure these reactions
• including exchange of technical ideas and
  coordination of single activities
• (leading institute Edinburgh).
• Determination of key features of nuclear
  properties, nuclear reactions,
• and the nuclear equation of state for
  astrophysical simulations and their
• experimental and/or theoretical verification
  (leading institute Basel).

21
Secondary neutrons fission
BUT Also light RIBs
And SARAF!
22
Fusion Reactions in the SunThe CNO cycle

• Proposed at GANIL

23
Mass accretion from a companion into a neutron
star (black hole).

• Role of 14O, 15O and 18Ne in the physics
• of x-ray bursts

M. Wiescher et al. Erice Conference, 2007 J.L.
Fisker et al., arXivastro-ph/070241
4He(15O,g)19NE
24
X-Ray Bursts and the rp process
Courtesy of Joint Inst. For Nuclear Astrophysics
(US)

• The rp process and x-ray bursts - site of
  nucleo-synthesis

25
Recent Experiments (in progress)
ISOLDE experiment IS424 (Sept. 07) (in
collaboration with P.J. Woods et al.).

• The use of a 17F beam from the upgraded
  REX-ISOLDE facility to study the
• astrophysically important 14O(a,p)17F reaction in
  time reverse kinematics.
• REX-ISOLDE MINIBALL
• Only 103 17F/s

On-line data of p-g coincidences Indicating the
1st excited state of 17F
26
GANIL experiment accepted by GANIL PAC (in
collaboration with Marialuisa Aliotta et al.)
Plan to investigate the direct 14O(a,p)17F
reaction at four different energies in the
energy region Ecm 1.0-2.5 MeV
Calculated total S(E) factor. Constructive ()
and destructive (-) interference between the
Jpp1- 6.15 MeV state and the direct l1
partial wave contribution are shown.
27
Long-learned lesson orders-of-magnitude
improvement in sensitivity of measurement
enhanced understanding and possibilities.
14N(d,2n)14O cross section and yield
14N(d,n)15O cross section and yield
for a 2 mA deuteron beam
for a 2 mA deuterons beam
But, extraction of atomic oxygen
28
8Li energies of interest
E(8Li MeV)
6
3
29
Examples of Reactions with RNBs for Astrophysics

• 8B(p,g)9C
• 8B(a,p)11C
• 9C(a,p)12N
• 11C(p,g)12N

30
Nucleosynthesis in AGB Stars - Maurizio M. Busso
Perugia
CNO, Ne-Na, Mg-Al Cycles
Important experimental and theoretical work has
addressed the CNO cycle.. e.g. 14N(p,g)15O
(see Schroeder et al. 1987 Angulo et al. 2001)
Runkle et al. 2002, Phys Rev C 66 Formicola et
al. 2004, Phys. Lett. B. 591 Runkle et al.
2005, Phys Rev C 94
. and of the hotter cycles of H-burning e.g.
for reacions on O isotopes and Na (leading to
Mg-A) Fox et al. 2004, Phys. Rev. Lett. 93
17Op Rowlad et al. 2004 Phys Rev. Lett 93 23Nap
31
RECENT LUNA ACHIEVEMENTS ON CNO
H.P. Trautvetter, ECT Nuclear Astrop. Workshop,
(Trento, May 2004)
32
Ne-Na and Mg-Al cycles
(p,g)
(p,a) (p,g)
But effects on higher nuclei (26Al) limited by
minimal of 20Ne production (at least with NACRE)
Arnould et al. 1999.
33
Finances

• each specialized task (1 - 3) 50 k
• general annual meetings 40 k
• support of coordinator 4 k
• total costs 194 k

34

• General considerations to remember -
• It is nuclear structure after all - masses, Q
  values, lifetimes,
• reaction theory, .
• Nuclear (astro) physics vs. modeling and
  standard astro.
• Nuclear astrophysics as motif for many RIB
  facilities.
• BUT
• How much time would a Facility devote to these
  time-consuming experiments