2010 Bormio

Materials provided by
Brad Sherrill
Thomas Glasmacher
Konrad Gelbke
Physics at FRIB
Wolfgang Bauer
Michigan State University
Wolfgang Bauer, Bormio, January 2010, Slide 1
Slid 1
Wolfgang Bauer, Bormio, January 2010, Slide 2
Slid 2
A question
Where do gold atoms come from?
Where do all atoms come from? (H, He, Li
from the Big Bang; the rest from stars)
Wolfgang Bauer, Bormio, January 2010, Slide 3
Slid 3
When did people first create gold
atoms from something else?
• 1924 Editors of Scientific American “Gold can be extracted from
mercury, but mercury cannot be transmuted into gold.”
• “It was not until 1941 that gold was actually prepared from a base
metal. By bombarding mercury with fast neutrons, Sherr, Bainbridge,
and Anderson obtained three radioactive isotopes of gold. Even that did
not fulfill the dream of the alchemists; the gold was radioactive and the
process did not produce wealth; it consumed it.” A Philatelic Ramble
Through Chemistry (Heilbronner and Miller; Verlag 1998)
Wolfgang Bauer, Bormio, January 2010, Slide 4
Slid 4
A hint from stellar spectra
• Not all stellar absorption spectra of the same surface temperature are
identical
“young” star
: T=4800 K ; [Fe/H] = 0.0
More heavier elements
in the younger star
old star
T=4700 K; CD-38:245 [Fe/H] = -4.0
! (Fe abundance /H abundance) Star $
[Fe/H] = LOG #
&
" (Fe abundance /H abundance) Sun %
Wolfgang Bauer, Bormio, January 2010, Slide 5
Slid 5
The abundances of heavier
elements change with time
• Gold atoms were made
in stars.
• How?
• The path to the answer
requires new
laboratory tools to
create new atoms
(designer atoms with
>20 extra neutrons)
that do not normally
exist on Earth
Morossi et al. 2007
Wolfgang Bauer, Bormio, January 2010, Slide 6
Slid 6
Our Science
Nuclear Physics
FRIB
RIKEN
FAIR
…
RHIC
JLab
LHC
…
Particle
Physics
SNO
Super-K
DUSEL
…
AstroPhysics
Wolfgang Bauer, Bormio, January 2010, Slide 7
Slid 7
Designer atomic nuclei
• Designer Atoms: The possibility
for a researcher to order an atom
with a specified number of
neutrons and protons
• There are about 263 stable
combinations found in nature,
e.g., 40Ca has 20 protons and 20
neutrons; (calcium has 22 known
isotopes)
• New combinations of neutrons
and protons are radioactive;
sometimes it is the novel
radioactivity that is interesting
1.5!10-14 m diameter
3.2!10-15 m
diameter
45Fe
two-proton decay: K Miernik et al. 2007
Phys. Rev. Lett. 99 192501 (see S. Tabor)
Wolfgang Bauer, Bormio, January 2010, Slide 8
Slid 8
Nuclear Physics explores the structure
and phases resulting from QCD
JLAB – QCD of nucleons
RHIC – QCD in liquid and nucleons
Picture from
Stephan
Scherer
QCD Lagrangian
Picture
from
BNL
FRIB – QCD of nuclei
Methods:
•Vnn (+3body) ab initio
•Configuration (shell)
•Functional Theory
•Relation to QCD
Wolfgang Bauer, Bormio, January 2010, Slide 9
Slid 9
Nuclei matter
• The nucleus presents a challenging quantum problem with two types of
fermions (protons, neutrons) and three of the four forces of nature
(strong, weak, electromagnetic) at work. The dominant force (strong) is
nonperturbative
• The properties of nuclei are relevant to other sciences
– Fundamental symmetries studies, e.g., in the search for neutrinoless double-beta
decay the rate is related to nuclear matrix elements
– Modeling astrophysical environments; e.g., nucleosynthesis in supernovae, which
depends on properties of exotic isotopes, or, neutron star properties which depend on
the nature of neutron-rich matter
• The properties of nuclei are important for a wide variety of applications
– Nuclear power (nuclear data is needed to optimize reactor design)
– Homeland security (forensics involves the same types of reactions, e.g. (n,2n),
important for astrophysics; detection of nuclear material and other threats)
– Stockpile stewardship (ditto)
– Medical diagnostics (99Mo story; 18F; etc.)
– Industrial and environmental tracers (7Be, 210Pb, 137Cs, etc.)
Wolfgang Bauer, Bormio, January 2010, Slide 10
Slid 10
Rare Isotope Production
Techniques: Uniqueness of FRIB
• Target spallation and fragmentation by light ions (ISOLDE/HRIBF/TRIUMF)
Target/Ion Source
beam
Accelerator
• Neutron induced fission (2-step target) (SPIRAL2/TRIUMF)
Neutrons/Photons
target
Accelerator
• In-flight Separation following projectile fragmentation/fission (RIKEN,FAIR,FRIB)
beam
Accelerator
Beams used without stopping
Beam
Fragment Separator
target
Gas catcher/ solid catcher + ion source
Wolfgang Bauer, Bormio, January 2010, Slide 11
Slid 11
Example: Discovery of 40Mg, 42,43Al, and 44Si
Baumann et al., Phys. Rev. C75 (2007) 064613; Nature 449 (2007) 1022
Production of new very exotic isotopes:
1.5!1017 48Ca nuclei (natW target, E/A = 141
MeV) " three 40Mg nuclei
S800 Analysis Line PID
Detector
Setup
Transport Beam Line
K500
Cyclotron
Timing Detectors
A1900 Fragment
Separator
Achromatic
Degrader
Production Target
Energy Loss in Si
K1200
Cyclotron
Flight Time
Wolfgang Bauer, Bormio, January 2010, Slide 12
Slid 12
Drip line extends further than expected
45
47
FRDM
HFB14
Starting with 42Al the p3/2 shell is filled,
indicating that 45Al is bound; and likely 47Al
is bound (p1/2)
Wolfgang Bauer, Bormio, January 2010, Slide 13
Slid 13
World view of rare isotope
facilities
Black – production in target
Magenta – in-flight production
Wolfgang Bauer, Bormio, January 2010, Slide 14
Slid 14
Wolfgang Bauer, Bormio, January 2010, Slide 15
Slid 15
Facility for Rare Isotope Beams,
FRIB Broad Overview
• Driver linac capable of E/A # 200 MeV for all ions,
Pbeam # 400 kW
• Early date for completion is in 2017
• Upgrade options (tunnel can house E/A = 400 MeV
uranium driver linac, ISOL, multi-user capability …)
Wolfgang Bauer, Bormio, January 2010, Slide 16
Slid 16
“Folded Linac” FRIB Configuration
• Location on MSU campus
– Green – existing
– Blue - new
Wolfgang Bauer, Bormio, January 2010, Slide 18
Slid 18
Alternative Configurations
• Features
– Tunnel separation
– Finished floor at 824’
– Folded tunnel at
stripper section
– Target area options
Straight linac
Folded linac
Separated tunnel cross-section
Wolfgang Bauer, Bormio, January 2010, Slide 19
Slid 19
MSU-Proposed FRIB
MSU Guiding Principles
• Provide broadest scientific opportunities early
• Plan for science-driven expansion
• Reduce technical risks
• Optimize for the FRIB Project within DOE requirements
Features
• Upgradable to 400 MeV/u
• Can add multi-user
• Can add ISOL targets
• Can double experimental area
Wolfgang Bauer, Bormio, January 2010, Slide 20
Slid 20
Opportunities with
Reaccelerated Beams of Rare Isotopes
• World-unique science opportunities with ReA3 by 2010 (MSU-funded
construction, NSF funded operation), with ReA12 in 2014
• User community pushing for earlier access to 10 MeV/u reaccelerated beams
– Develop equipment, theoretical techniques, form collaborations (similar to AGS prior to RHIC)
Wolfgang Bauer, Bormio, January 2010, Slide 21
Slid 21
FRIB Organization with Advisory Committees
and DOE Interfaces
Wolfgang Bauer, Bormio, January 2010, Slide 22
Slid 22
Experimental Areas
• Scope
– Experimental areas for fast,
stopped and reaccelerated
beams
• Approach
– Reconfigurable areas for fast,
stopped and reaccelerated
beam experiments prior to CD4
– Equip all areas with a suite of
equipment before CD4
– Possibility for future sciencedriven area expansions
• Technical specifications
– 47,000 sq ft operational
experimental areas at CD4
Wolfgang Bauer, Bormio, January 2010, Slide 23
Slid 23
Experimental Areas Expansion Options
! More than 60,000 sq ft additional space
available to meet future science needs
! High flexibility in layout of expansions
Example:
NNSA Neutron Facility as
proposed by LLNL
! Expansions possible without significant
down time
Wolfgang Bauer, Bormio, January 2010, Slide 24
Slid 24
Timeline for establishment of FRIB
• The timeline for FRIB is dependent on funding by congress and
approval by DOE
Wolfgang Bauer, Bormio, January 2010, Slide 25
Slid 25
What New Nuclides Will FRIB Produce?
Key: All Produced are Available for Study
• FRIB will produce
more than 1000 NEW
isotopes at useful
rates
• Interaction with
Theory is key to
making the right
measurements
• Exciting prospects for
study of the drip line
to mass 120
(compared to 24)
• Production of most of
the key nuclei for
astrophysical
modeling
• Harvesting prospects
near stability
Rates are available at http://groups.nscl.msu.edu/frib/rates/
Wolfgang Bauer, Bormio, January 2010, Slide 26
Slid 26
NRC Rare Isotope Science
Assessment Committee, RISAC
“The
committee
concludes that
the science
addressed by a
rare-isotope
facility, most
likely based on
a heavy ion
linac driver,
should be a
high priority for
the United
States.”
Wolfgang Bauer, Bormio, January 2010, Slide 27
Slid 27
The Science Drivers for FRIB
NRC Rare Isotope Science Assessment Committee (RISAC) Report, 2007
• Nuclear Structure
– Explore the limits of existence and study
new phenomena (IW,GR, et al.)
– Possibility of a broadly applicable model
of nuclei and how the interact (AV, et al.)
– Probing neutron skins (PC, IW, et al.)
– Synthesis of superheavy elements
• Nuclear Astrophysics
– The origin of the heavy elements (IW,GR)
– Explosive nucleosynthesis
– Composition of neutron star crusts
– EOS of asymmetric matter (JP, et al.)
• Fundamental Symmetries
– Tests of fundamental symmetries, Atomic
EDMs, Weak Charge
• Other Scientific Applications
– Stockpile stewardship, materials, medical,
reactors
Wolfgang Bauer, Bormio, January 2010, Slide 28
Slid 28
FRIB specialty – Produce new exotic
isotopes
V(r)
• Large neutron skins
• Modified mean field
• Resonance properties
11Li
r
208Pb
New
80Ni
Science: Pairing in low-density material, new tests of nuclear models, open
quantum system, Interaction with continuum states - Efimov States - Reactions
Wolfgang Bauer, Bormio, January 2010, Slide 29
Slid 29
New insight and physics from
extreme halos and skins
Example: 42Mg (Predicted to be produced at 10 atoms/day)
T
Theory
- 100 keV Sn BA Brown
Wolfgang Bauer, Bormio, January 2010, Slide 30
Slid 30
How do we model nuclei?
• The origin of the strong force that binds nuclei is QCD (How would we
prove that?)
• We construct potentials based on neutron and proton scattering data
and properties of light nuclei (Bonn, Reid, Illinois AV18, Nijmegen, etc.)
• QCD Inspired EFT (String Theory Inspired – Hashimoto et al.)
S Aoki
Goal:
Develop an
Effective
Field Theory
based on
QCD
Symmetries
(Furnstahl,
van Kolck,
Navrátil,
Vary, …)
Wolfgang Bauer, Bormio, January 2010, Slide 31
Slid 31
Properties of exotic isotopes are essential
in determining NN and NNN potentials
• Neutron rich nuclei were key
in determining the isospin
dependence of 3-body forces
and the development of IL-2R
from UIX
S. Pieper
B.Wiringa,
et al.
• New data on exotic nuclei
continues to lead to
refinements in the
interactions
• EFT developments, LQCD
and even String Theory are
providing insight for ab initio
theories, but they need
grounding in data
Wolfgang Bauer, Bormio, January 2010, Slide 32
Slid 32
Theory Road Map: Comprehensive Model of
Nuclear Structure and Reactions
• Theory Road Map – comprehensive
description of the atomic nucleus
– Ab initio models – study of neutron-rich, light
nuclei helps determine the force to use in
models (measurement of sensitive
properties for N=14, 16 nuclei)
– Configuration-interaction theory; study of
shell and effective interactions (study of key
nuclei such as 54Ca, 60Ca, 122Zr)
– The universal energy density functional
(DFT) – determine parameters (broad view
of mass surface, BE(2)s, BE(4)s, fission
barrier surface, etc.)
– The role of the continuum and reactions
and decays of nuclei (halo studies up to A
~100)
• IMPORTANT: Understand and
select the most sensitive
measurements
Energy density functional
Configuration
interaction
Ab initio
Continuum
Relationship to QCD (LQCD)
Wolfgang Bauer, Bormio, January 2010, Slide 33
Slid 33
How do we know QCD is responsible for
nuclei? Theory
Experiment
• Lattice QCD has the promise to
verify QCD as the correct
description for the strong force
in nuclei
• The lattice may be able to
provide the isospin dependence
of the NNN force needed to
understand nuclei
• Comparison of this dependence
to rare isotope data allows a
test of lattice QCD in nuclei
T. Otsuka
arXiv:0908.2607v1
NNN force may be the
solution to understanding
the Oxygen drip line
Wolfgang Bauer, Bormio, January 2010, Slide 34
Slid 34
24O
– Study of changing single particle E
C.R. Hoffmann* et al., PL B672, 17 (2009)
Winner, 2010 Dissertation Award in Nuclear Physics
• High-lying first excited 2+ state
is strong evidence doubly
magic nucleus
• Far from stability, this 2+ state
can be unbound with respect
to neutron emission
23O+n
24O
Wolfgang Bauer, Bormio, January 2010, Slide 35
Slid 35
Nucleon knockout technique to
measure wave functions
12Be
N=8
Shell Model
d3/2
d5/2
2s1/2
p1/2
p3/2
s1/2
neutrons
12Be
5/2+
Ex
(keV)
1778
1/2-
310
L= 2
L= 1
L= 0
11Be
1/2+ 0
P. G. Hansen and J. A. Tostevin, Annu. Rev. Nucl. Part. Sci. 53, 219 (2003).
Wolfgang Bauer, Bormio, January 2010, Slide 36
Slid 36
Recoil momenta show which orbit
the nucleons came from
Shell Model
100% (0p)2
d5/2
2s1/2
p1/2
p3/2
s1/2
neutrons
N=8 is not a shell closure in 12Be: It is just about the opposite with
the wave function of 32% (0p)8, 34% (1s)2 , 34% (0d)2
Wolfgang Bauer, Bormio, January 2010, Slide 37
Slid 37
Solar System Abundances
• The abundance of elements tell us about the history of events prior to
stellar formation
Solar system abundances
Lodders (2003)
Wolfgang Bauer, Bormio, January 2010, Slide 38
Slid 38
Where do gold atoms come from?
An r-process
• E. M. Burbidge, G. R. Burbidge, W. A. Fowler, and F. Hoyle. (1957).
"Synthesis of the Elements in Stars". Rev Mod Phy 29: 547, must be an rprocees, but …
• We know they must be made in a neutron-rich environment T > 109 K, $
20-28 cm-3 , that lasts for about 1 second; called the rapid-neutron
neutron " 10
capture process, r-process
• Type II supernovae are a possible site (variants)
– Neutrino driven shock wave
– Models do not produce the entropy and neutron flux needed to match abundance data
(although we can’t say that for sure)
– Shock waves in C-O layers
– Magnetic outflows
• Colliding neutron stars would also work, but there does not seem to be
enough of these in the early universe to explain how much heavier
elements we see
• Once the underlying physics is known, we can infer information of the site
Wolfgang Bauer, Bormio, January 2010, Slide 39
Slid 39
r(apid)-Process
Calculation: Shinja Wanayo, Tokyo
%-Decay
n-Capture
Wolfgang Bauer, Bormio, January 2010, Slide 40
Slid 40
r(apid)-Process - the movie
Wolfgang Bauer, Bormio, January 2010, Slide 42
Slid 42
Neutrino Heated Wind in
Supernovae
• Review: Woosley and Janka Nature Physics 1, 147 (2005)
• Problem: The entropy is not high enough!
Wolfgang Bauer, Bormio, January 2010, Slide 43
Slid 43
Uncertainty between models
and nuclear properties
101
Astrophysics
Hot bubble
Classical model
Same nuclear physics
Abundance
100
10
ETFSI-Q masses
ETFSI-1 masses
0
10
10-1
10
10-2
10
10-3
10
10-4
Nuclear physics
1
Same (classical) r-process model
-1
-2
-3
Freiburghaus et al. 1999
-4
10
Mass number
100
120
140
160
180
200
220
Mass number
Wolfgang Bauer, Bormio, January 2010, Slide 44
Slid 44
Reach of FRIB – Will Allow
Modeling of the r-Process
••#-decay
#-decayproperties
properties
••masses
masses(Trap
(Trap++TOF)
TOF)
••(d,p)
(d,p)to
toconstrain
constrain(n,$)
(n,$) Known half-life
••fission
fissionbarriers,
barriers,yields
yields
82
FRIB reach
for (d,p)
N=126
126
50
Current
NSCL reach
reach
First experiments
82
28
(70) Yb
(69) Tm
(68) Er
(67) Ho
(66) Dy
50
FRIB reach for
half-lives
RISAC
Key
Nuclei
Future
Reach
Wolfgang Bauer, Bormio, January 2010, Slide 45
Slid 45
Example: Low Energy Beam Ion Trap (LEBIT)
stop fragments in helium-gas cell, extract, purify, and store in Penning trap
Penning Trap
Mass Spectrometry
• Measurements of masses, moments,
fission barriers, and deformations
provide guidance for the development
of an energy density functional with
predictive power
24
Cooling and
Bunching
Gas stopping
of fast ions
TOF [ µs]
< 1 eV
23
22
21
19
100 MeV/u
38
++
Ca
G. Bollen et al.
PRL 96 (2006)152501
18 0+ " 0+ %+-emitter
-10
Degrader
&m = 280 eV
&m/m=8·10-9
20
-5
0
5
10
fRF [Hz] - 7595522
Since 2005: accurate masses for more than 30 isotopes of more than 10 elements: 33Si,
29, 34P,37,38Ca, 40-44S, 63-65Fe, 64-66Co, 63-64Ga, 64-66Ge, 66-68,80As, 68-70,81,81mSe, 70m,71Br
Wolfgang Bauer, Bormio, January 2010, Slide 46
Slid 46
Goal: Understanding of
Astrophysical Environments
• Use observational data to infer
conditions at the site by modeling
• Accurate modeling requires
• that we make the same isotopes
that participate in astrophysical
environments
• reproduce the nuclear reactions
that occur in those environments
• The hard part is that nature
produces isotopes in environments
like the r-process with T > 109 K, $
20-28 cm-3
neutron " 10
Sneden 2003; Cowan 2006
model
n-star mergers
Price & Rosswog 2006
observation
Crab
Nebula
Mt Palomar
Wolfgang Bauer, Bormio, January 2010, Slide 47
Slid 47
Simulation of Solar System
Abundances
Parameters:
Supernovae type
Ia and II
Number (77 Ms
11-40)
Progenitor mass
distributions
Age of the galaxy
…
Results:
SN rate
1/3 comes from
type Ia
7Li abundance
metalicity vs. time
etc.
Success ! ?
Timmes, Woosley, Weaver 1995
Wolfgang Bauer, Bormio, January 2010, Slide 49
Slid 49
Tests of Nature’s Fundamental
Symmetries
• Angular correlations in #-decay
and search for scalar currents
o
o
Mass scale for new particle
comparable with LHC
6He
and 18Ne at 1012/s
• Electric Dipole Moments
o
225Ac, 223Rn, 229Pa
sensitive than
(30,000 more
I > 1010/s)
199Hg;
• Parity Non-Conservation in
atoms
o
weak charge in the nucleus
(francium isotopes; 109/s)
• Unitarity of CKM matrix
o
o
e
!
212Fr
Z
Vud by super allowed Fermi decay
Probe the validity of nuclear
corrections
Wolfgang Bauer, Bormio, January 2010, Slide 50
Slid 50
Rare Isotopes For Society
• Isotopes for medical research
– Examples: 47Sc, 62Zn, 64Cu, 67Cu, 68Ge, 149Tb, 153Gd, 168Ho, 177Lu, 188Re, 211At, 212Bi,
213Bi, 223Ra (DOE Isotope Workshop)
– '-emitters 149Tb, 211At: potential treatment of metastatic cancer
• Reaction rates important for stockpile stewardship – non-classified
research
– Determination of extremely high neutron fluxes by activation analysis
– Rare isotope samples for (n,(), (n,n’), (n,2n), (n,f) e.g. 88,89Zr
» Same technique important for astrophysics
– More difficult cases studied via surrogate reactions (d,p), (3He,' xn) …
• Tracers for Geology, Condensed Matter (8Li), material studies, …
Isotope harvesting is included
in the FRIB scope
Wolfgang Bauer, Bormio, January 2010, Slide 51
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Wolfgang Bauer, Bormio, January 2010, Slide 52
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What’s next?
Wolfgang Bauer, Bormio, January 2010, Slide 54
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