Science of rare isotopes: connecting nuclei with the universe

1
Science of rare isotopes connecting nuclei with
the universe Witold Nazarewicz (UTK, ORNL,
UWS) APS Annual Meeting, St. Louis, April 12,
2008

• Two take-away messages
• Nuclear scientists, experimentalists and
  theorists, are getting better and better at
  controlling short-lived nuclei, in particular
  those which are useful
• Rare isotopes are the key to answering questions
  in many areas of science

• Introduction
• Territory
• Science
• Connections and Relevance
• Perspectives

2
Introduction
3
Some nuclei are more important than others
Over the last decade, tremendous progress has
been made in techniques to produce designer
nuclei, rare atomic nuclei with characteristics
adjusted to specific research needs
nuclear structure
tests of fundamental laws of nature
45Fe
applications
astrophysics
4
National Academy 2007 RISAC Report BPA Rare
Isotope Science Assessment Committee
Nuclear science is entering a new era of
discovery in understanding how nature works at
the most basic level and in applying that
knowledge in useful ways

• Exciting opportunities in
• Nuclear Structure
• Nuclear Astrophysics
• Tests of fundamental symmetries with
  rare-isotopes
• Scientific Applications

5
Radioactive Ion Science Timeline (from RISAC
Report)
Relativistic Coulomb excitation of 32-Mg at RIKEN
Direct radiative capture with 21-Na at
ISAC-I 38m-K ?-??correlations at TRINAT
100-Sn discovered at GSI and GANIL
Europe
Japan
First mass measurement of short-lived nuclei at
PS in CERN
First accelerated beam experiment (13-N) at LLN
Two-proton emitters discovered at GSI and
GANIL
Canada
Momentum distribution of halo at RIKEN
Z105 (Db) discovered in Dubna
Measurement of half-life of r-process nucleus at
Studsvik
Mössbauer effect
Projectile-fisson of 238-U and Z112 discovered
at GSI
Proton emission discovered at Harwell
BBHF theory of nucleosynthesis
Z108 chemistry at GSI
Acceleration of RIBs at LLN
Beta-delayed proton radioactivity discovered at
Dubna and McGill
Island of inversion at N20 and shape coexistence
in proton-rich Hg at iSOLDE
Targeted alpha therapy at ISOLDE
ISOLTRAP
First ISOL experiment in Copenhagen
Laser ion source at ISOLDE
Becquerel discovers radioactivity The Curies
discover polonium
Neutron-induced fission
IGISOL at Jyväskylä
Isotopic tracer technique by von Hevesy
Nobel Prize for magic numbers
Nobel Prize for unified model
6-He produced in Copenhagen
Explanation of magic numbers
RIKEN
SPIRAL1
ISOLDE
GANIL
GSI
ISAC-I
REX-ISOLDE
Nobel Prize for unified model
1900
1930
1960
2000
Parity violation in beta decay
Fermi builds controlled fission reactor
NSCL
HRIBF
Shell structure changes in exotic nuclei at
ATLAS/HRIBF/NSCL
First therapeutic application of artificial
radionuclide
Nobel Prize for magic numbers
Nobel Prize for nucleosynthesis
Invention of PET scanner
1940 The Rockefeller Foundation funds the first
cyclotron dedicated for biomedical radioisotope
production at Washington University in St. Louis.
The cyclotron first used radioactive phosphorus
for treating leukemia.
Trapped francium at Stony Brook
Explanation of magic numbers
First in-flight separator at Oak Ridge
First in-flight fragmentation experiments at
Berkeley
Radiochemistry used to monitor nuclear weapons
tests
Shell structure of exotic nuclei with knockout
reactions at NSCL
6-He enhanced reaction cross sections at TwinSol
beta-NMR demonstrated at ANL
Z100 (Fm) discovered
First application of radiochemistry to inertial
fusion target diagnosis
BBHF theory of nucleosynthesis
Studies with accelerated 132-Sn and 82-Ge at HRIBF
Neutron halos discovered at Berkeley
21-Na ?-??correlations at Berkeley
Measurement of half-life of r-process nucleus at
TRISTAN
Charge radius of 6-He at ATLAS 78-Ni lifetime at
NSCL
United States
6
Science Questions and challenges
7
Designer Nuclei in Nuclear Landscape
Experimental Nuclear Structure _at_ APS
April08 Baumann (R3.3), Koller (W3.1), Fallon
(W3.2) Tanihata (W3.3), H14, M14, R14, X14
82
126
protons
terra incognita
50
82
28
stable nuclei

• How do protons and neutrons make stable nuclei
  and rare isotopes?
• What are properties of neutron matter?
• What are the heaviest nuclei that can exist?
• What is the origin of simple patterns in complex
  nuclei?

20
50
8
28
known nuclei
2
20
8
2
neutrons
8
Structure of rare isotopes Old paradigms
revisited. Crucial input for theory
No shell closure for N8,20,28 for drip-line
nuclei new shells at 14,16,32
9
6,8He 11Li Charge Radii and Masses of Halo
NucleiPrecision measurements provide stringent
test of nuclear models
ANL (2004)
T1/2 806 ms
ANL/GANIL (2007)
T1/2 119ms
T1/2 8.6 ms
10
Neutron skins
100Sn
Sn isotopes
protons
7
N/Z1
density (nucleons/fm3)
neutrons
radius (fm)
100Zn
protons
6
The only laboratory access to matter made
essentially of pure neutrons
N/Z2.33
60
80
100
120
0
2
8
6
4
r (fm)
neutron number
11
Neutron-rich matter and neutron skins
Giant dipole
E1 strength
GSI 2005
12
The Limit of Mass and Charge superheavies
Current Affairs
118
116
115
114
RIKEN
113
Dubna LLNL
GSI
J. Phys. G 34, R165 (2007)
13
How does the physics of nuclei impact the
physical universe?

• What is the origin of elements heavier than iron?
• How do stars burn and explode?
• What is the nucleonic structure of neutron stars?

Thielemann (T3.1) Hans A. Bethe Prize
p process
s-process
L3
S8
r process
rp process
Nova
Neutron star
L8 J14
Crust processes
T Pyxidis
stellar burning
protons
Calder (E5.2), Frebel (R3.1), Qian (R3.2) Hix
(W5.3), D8, H15, J15
neutrons
14
Rare isotope measurements for novae
Example of synergy between nuclear science and
astronomy
predicted ?-ray flux from decaying radionuclides
18F, 22Na... synthesized in explosion
Synthesis of e.g. 18F, 22Na, (26Al) very
important for characteristic g-ray emission from
nova
15
r (apid neutron capture) process
The origin of about half of elements heavier than
iron Goes through neutron-rich rare isotopes
16
Testing the fundamental symmetries of nature
Experiments addressing questions o the
fundamental symmetries of nature can take
advantage of certain exotic isotopes because
aspects of their structure greatly magnify the
size of the symmetry-breaking processes being
probed
EDM searches in
17

• 7 cases (10C,14O,, 42Sc) measured _at_CPT/APT (ANL)
  stay tuned
• Advances in isospin mixing calculations

38mK
18
Roadmap for Theory of Nuclei
...provides the guidance
Overarching goal To arrive at a comprehensive
microscopic description of all nuclei and
low-energy reactions from the the basic
interactions between the constituent nucleons

• There is no one size fits all theory for
  nuclei, but the theoretical approaches need to be
  bridged
• Main uncertainty spin-isospin sector. Here, data
  from rare isotopes are crucial

Schmidt (B3.1), Dean (B3.3), Bogner (D4.2),
Navratil (D4.3),Charity (X3.1) E14, L14, X15
19
Ab initio calculations (nuclei, neutron droplets,
nuclear matter)
GFMC S. Pieper
1-2 calculations of A 6 12 nuclear energies
are possible excited states with the same quantum
numbers computed
20
Science scales with processors
Example 1 Large Scale DFT Mass Table Calculations
_at_

• 9,210 nuclei
• 599,265 configurations
• Using 3,000 processors - about 25 CPU hours

Number of processors gt number of nuclei!
Cycles allocated by DOE's Innovative and Novel
Computational Impact on Theory and Experiment
(INCITE) program
_at_
21
Connections and Relevance
22
Connections to quantum many-body systems

• Understanding the transition from microscopic to
  mesoscopic to macroscopic
• Symmetry breaking and emergent phenomena
• Quantum chaos
• Open quantum systems
• Dynamical symmetries and collective dynamics

Superfluid Fermionic Systems The Unitary Gas
(Seattle/Warsaw)

• Dilute fermion matter
• strongly correlated
• very large scattering length
• Low-density neutron matter
• Cold fermions in traps

23
Emergent collective behavior in nuclei
Quantum phase transitions
152Sm
148Sm
154Sm
Vibrator
Soft
Rotor
Transitional
Deformed
Spherical
Energy
Transitional rare isotopes
Deformation
24
Applications of Rare Isotopes How can our
knowledge of nuclei and our ability to produce
them benefit the humankind?
Yttrium Reaction Network
W14

• Stockpile stewardship
• Required cross sections involve many processes,
  including (n,?), (n,n'), and (n,xn) as well as
  (p,n), (p,2n) etc.)
• Materials science, transmutation of waste,
  environmental science
• Can we design an economically competitive, energy
  efficient, reduced-waste nuclear reactor?
• Medical and biological research

25
What are the next medically viable radioisotopes
required for enhanced and targeted treatment and
functional diagnosis?
Example Targeted Alpha Therapy in vivo
The radionuclide 149Tb decays to alpha particles
17 percent of the time and has a half-life of 4.1
hours, which is conveniently longer than some
other alpha-emitting radionuclides. Lower energy
alpha particles, such as in 149Tb decays, have
been shown to be very efficient in killing cells,
and their short range means that minimal damage
is caused in the neighborhood of the target cells.
?-knife!
First in vivo experiment to demonstrate the
efficiency of alpha targeted therapy using 149Tb
produced at ISOLDE, CERN
G.-J. Beyer et al. Eur. J. Nucl. Med. and
Molecular Imaging 33, 547 (2004)
26
5106
Monoclonal Antibody
2 days later the mice have been divided into 4
groups
27
Perspectives
28
Experiment
29
Theory Connections to computational science
1Teraflop1012 flops 1peta1015 flops (next 2-3
years) 1exa1018 flops (next 10 years)
http//www.top500.org/
challenge utilize leadership class computers
30
Outlook
The study of rare isotopes makes the connection
between the Standard Model, complex systems, and
the cosmos

• Exciting science old paradigms revisited
• Interdisciplinary science
• Science relevant to society

Over the last decade, tremendous progress has
been made in techniques to produce designer
nuclei, rare atomic nuclei with characteristics
adjusted to specific research needs. Guided by
unique data on short-lived nuclei, we are
embarking on a comprehensive study of all nuclei
based on the most accurate knowledge of the
inter-nucleon interaction, the most reliable
theoretical approaches, and the massive use of
the computer power available at this moment in
time. The prospects are excellent.
Thank You
31
Backup
32
(No Transcript)
33
Nuclear DFT works well for BE differences
S. Cwiok, P.H. Heenen, W. Nazarewicz Nature, 433,
705 (2005)
Stoitsov et al., 2008

• Global DFT mass calculations HFB mass formula
  ?m700keV

34
Nuclear Structure the interaction
Effective-field theory (?PT) potentials
Vlow-k can it describe low-energy observables?

• Quality two- and three-nucleon interactions exist
• Not uniquely defined (local, nonlocal)
• Soft and hard-core
• The challenge is
• to understand their origin
• to understand how to use them in nuclei

Bogner, Kuo, Schwenk, Phys. Rep. 386, 1 (2003)
N3LO Entem et al., PRC68, 041001
(2003) Epelbaum, Meissner, et al.
35
Helium resonances
Ab initio Reactions
5He phase shifts
Coupled Clusters
GFMC
7Be(p,g)8B, S17
No Core Shell Model
36
Bimodal fission in nuclear DFT
37
Synthesis of SHE
Observation of fusion enhancement at sub-barrier
energies in 134Sn64Ni (HRIBF, 2007)
Loveland (2007) (i) The use of radioactive
beams in the synthesis of heavy nuclei can lead
to the formation, at reasonable rates, of a group
of neutron-rich nuclei not reachable with stable
beams. These nuclei are predicted to have longer
halflives than existing nuclei. (ii) The best
(i.e., highest production rate) reactions for
producing these nuclei involve the use of lighter
n-rich radioactive beams. (iii) When considering
reactions involving radioactive beams, it is
important to evaluate the cross section beam
intensity product. (iv) The best way to produce
most heavy nuclei, especially those of high Z, is
to use stable beams.

• 1000 ions/sec
• Probing the influence of neutron excess on fusion
  at and below the Coulomb barrier
• Large sub-barrier fusion enhancement has been
  observed
• Inelastic excitation and neutron transfer play an
  important role in the observed fusion enhancement

38
Novae nucleosynthesis up to A 40 mass region
T 4x108 K ? 103 g cm-3
27Si
28Si
25Al
24Al
26Al
27Al
nova (artists impression)
rp-process onset
21Mg
22Mg
23Mg
24Mg
25Mg
26Mg
23Na
21Na
22Na
20Na
NeNa cycle
breakout from HCNO
18Ne
20Ne
19Ne
21Ne
22Ne
reaction network for explosive hydrogen burning
17F
18F
19F
15O
14O
16O
17O
18O
HCNO
13N
14N
15N
(p,?) and (?,p) reactions on proton-rich nuclei
stable
12C
13C
unstable
39
Rare isotope measurements for r-process
r-process (?,n) campaign towards 110Zr (NSCL)
New precise masses of neutron-rich nuclei (ANL,
ISOLDE, Jyvaskyla, TRIUMF,
40
Precise masses from Penning TRAP facilities (only
selected examples)
from J. Aysto
41
Electric Dipole Moment Searches (Time-reversal
violation New Standard Model)
T4
energy
225Ra
1/2-
55.2 keV
0
0
R
L
1/2
experiment
octupole deformation
Static octupole deformation can enhance the
effect of CP-violating interactions. A handful of
such nuclei have been identified over the years,
for example 229Pa and 223,225Ra. Such
pear-shaped nuclei occur only rarely and only in
special regions of the nuclear chart. Theory has
confirmed that the size of the EDM (if it exists)
is expected to be enhanced in these nuclei
compared with 199Hg, the most sensitive stable
nucleus presently used in EDM searches, by a
factor of several hundred to several thousand.
42
Radioactive Ion Beam Facilities Timeline
HIE-ISOLDE
ISOLDE
ISAC-II
ISAC-I
SPIRAL2
SPIRAL
FAIR
SIS
RIBF
RARF
NSCL
HRIBF
CARIBU_at_ATLAS
FRIB