Brad Sherrill NSCL Director Introduction Big picture challenges for nuclear science Rare isotopes The specific challenges Modeling Nuclei The origins of atoms Forces in nuclei ID: 599061
Download Presentation The PPT/PDF document "Frontiers in Nuclear Physics" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Frontiers in Nuclear Physics
Brad Sherrill, NSCL DirectorIntroduction“Big picture” challenges for nuclear scienceRare isotopesThe specific challenges Modeling Nuclei The origins of atoms Forces in nuclei Uses of isotopesSummary
Sherrill EBSS 2015
1Slide2
Multiple choice question
Where do the majority of gold atoms come from? They were mostly made by human activityThey were produced in neutron star collisionsThey were produced in supernovaeThey were produced in stars like our sunWe are not sure where they are madeSherrill EBSS 20152Slide3
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) Sherrill EBSS 20153Slide4
2012 Decadal Study of Nuclear Physics – National Research Council
Sherrill EBSS 20154Four overarching questions for the field of nuclear science:(1) How did visible matter come into being and how does it evolve?(2) How does subatomic matter organize itself and what phenomena emerge?(3) Are the fundamental interactions that are basic to the structure of matter fully understood?(4) How can the knowledge and technological progress provided by nuclear physics best be used to benefit society?http://www.nap.edu/catalog/13438/nuclear-physics-exploring-the-heart-of-matterSlide5
The Major Nuclear Science Facilities – Relativistic Heavy Ion Collider
Sherrill EBSS 20155https://www.ntnu.edu/physics/theoretical/thermqcdSutdy of the phases of nuclar matterJ. AndersonProduction and study of new states of QCD matter Slide6
Jefferson Laboratory – 12
GeV Upgradesome examples of science, more to comeSherrill EBSS 20156http://www.usqcd.org/hadron.htmlSemi-inclusive deep inelastic scattering
http://
arxiv.org
/
pdf
/0812.2208.pdfSlide7
After FRIB the next major facility will be the Electron Ion Collider (
e+p 100 GeV)Science Topics:Proton SpinMotion of quarks and gluons in the proton (and nuclei)QCD matter at an extreme gluon densityTomographic images of the proton (and nuclei)Quark hadronizationSherrill EBSS 20157EIC White Paperhttp://arxiv.org/pdf/1212.1701v3.pdfSlide8
Fundamental Symmetries and NeutrinosIs the neutrino its own anti-particle (
Majorana particle)?Sherrill EBSS 20158Mixing of neutrinos shows mass differencesNo neutrinos in the final state – Lepton number violoatedSeveral tons of material is required to push the limitsSlide9
Nuclear Physics explores the structure and phases resulting from QCD
QCD in nuclei - FRIBPicture from StephanSchererQCD Lagrangian
Picture from BNL
QCD of
nucleons (and nuclei) – JLAB/EIC
QCD
liquid
and nucleons - RHIC
Sherrill EBSS 2015
9Slide10
How do we understand nuclear structure?Oral history that when the Schrodinger equitation was published Dirac declared that chemistry had come to and end – its content is contained in one equation (Walter Kohn Nobel Lecture 1999)
Dirac added: too bad this equation is to complicated to allow solution in most casesIn nuclear physics we have a similar situation. We believe the underlying force can be described by QCD and the general form of the QCD Lagrangian (more generally the by the Standard Model of particle physics)Too bad this equation is to complicated to allow solution in most casesChallenge – find the appropriate techniques to model nuclei, preferably grounded in QCD (but we will take whatever works)Sherrill EBSS 201510Slide11
The light hadron spectrum from Lattice QCD
Sherrill EBSS 2015 11Dürr, Fodor, Lippert et al., Science 322 (2008) 1224 Neutron-Proton Mass Difference: Sz. Borsanyi, et al., Science 27 March 2015:
vol 347 p 1452Slide12
What a proton really looks like99% of the visible mass of the universe is in protons and neutrons (nucleons)
Only a few percent of the mass of the proton (5%) is from the quark mass (LQCD is now able to demonstrate a heavy proton mass from light quarks; Dürr et al. Science 322 (2008))Frank Lee http://home.gwu.edu/~fxleeSherrill EBSS 201512Slide13
A Challenge for Nuclear Science
We want to model physical phenomena that are the result of the strong forceThis includes understanding atomic nuclei, hadrons, QGP, …We have made remarkable progress in modeling hadrons – Nobel prize in 2004 Gross, Politzer, Wilczek ; LQCD calculation of nucleon and meson masses (Dürr, Fodor, Lippert et al., Science 322 (2008))There is room for significant progress in understanding atomic nucleiIllustration from David DeanSherrill EBSS 2015 13JPARC
JLABFAIR
RIBF
FRIB
FAIR
GANIL
…
RHICSlide14
Nuclear SpectroscopyM. Allmond (ORNL), B. Kay (ANL)
Incredible variety of excited states in nuclei!Regular bands I(I+1) behavior: rotationalnℏΩ behavior: vibrationalRegular bands signatures of nuclear collectivity (deformed liquid-drop like)Bands with no visible patterns are signature of single-particle effects (shell-effects)Where are the effects of the short-range nature of the nuclear force? GAMMASPHERESherrill EBSS 2015 14From W. Nazarewicz, in An Advanced Course in Modern Nuclear Physic
s, J.M. Aria, M. Lozano (eds.), Springer (2001)Slide15
Our Challenges
Develop a comprehensive model of atomic nuclei – How do we understand the structure and stability of atomic nuclei from first principles?Understand the origin of elements and model extreme astrophysics environments Use of atomic nuclei to test fundamental symmetries and search for new particles (e.g. in a search for CP violation) Search for new applications of isotopes and solution to societal problemsSherrill EBSS 201515Why do atoms exist?Where do atoms come from?What are atoms made of?What are they good for?Studies at the extremes of neutron and proton number are necessary to answer these questions.Slide16
The Nuclear Landscape – lectures by M. Thoennessen (MSU/NSCL)
Sherrill EBSS 201516256 “Stable” – no decay observed3184 Total in the NNDC DatabaseSlide17
World-Wide Rare Isotope ProgramHow – Lectures by M. Thoennessen, M. Couder
(ND) Sherrill EBSS 201517Slide18
Major US Project – Facility for Rare Isotope Beams, FRIBFunded by DOE Office of Science – 2020 completion
Key Feature is 400kW beam power (5 x1013 238U ions/s)Separation of isotopes in-flightFast development time for any isotopeSuited for all elements and short half-livesExperiments with fast, stopped and reaccelerated beamsSherrill EBSS 201518Slide19
Prediction of the limits of the nuclear landscape
Sherrill EBSS 201519J. Erler et al., Nature 486, 509 (2012); AV Afanasjev et al. PLB 726, 680 Total number of 6900(500) possible for atomic numbers less than 120. Slide20
There are Predicted Limits to the Number of Isotopes
Sherrill EBSS 201520Estimated Possible: Erler, Birge, Kortelainen, Nazarewicz, Olsen, Stoitsov, Nature 486, 509–512 (28 June 2012) , based on a study of EDF models“Known” defined as isotopes with at least one excited state known (1900 isotopes from NNDC database)Represents what is possible nowSlide21
The Number of Isotopes Available for Study at FRIB
Sherrill EBSS 201521Estimated Possible: Erler, Birge, Kortelainen, Nazarewicz, Olsen, Stoitsov, Nature 486, 509–512 (28 June 2012) , based on a study of EDF models“Known” defined as isotopes with at least one excited state known (1900 isotopes from NNDC database)For Z<92 FRIB is predicted to make > 80% of all possible isotopesSlide22
The value of isotopesDefinition: An isotope is one of an element’s physical forms.
July 31, 2015 the price of gold was $1095.46 per ounceFor 1 cent, you can buy 3000000000000000000 Gold-197 atoms (3x1018 atoms)Tritium (radioactive form of hydrogen, Hydrogen-3 or 3H, used in self illuminating signs) $1.4M per ounceColorless diamond $2M per ounce ( 1 carat = 0.007 ounce)Record: Berkelium-249 $280M per ounceSherrill EBSS 201522Slide23
Calcium IsotopesNormal Calcium: Calcium-40 $.32 per ounce
Expensive Calcium: Calcium-48 (.2% natural abundance) $6M per ounceSherrill EBSS 2015, Slide 23
20 protons
28 neutrons
20 protons
20 neutronsSlide24
Goal of Current Isotope ResearchGoal: Calcium-60 ( At FRIB we will spend about $10,000 for 1000 atoms)
Sherrill EBSS 20152420 protons40 neutronsSlide25
Comparison of Calculated and Measured Binding Energies with NN models
Greens Function Monte Carlo techniques allow up to mass number 12 to be calculatedBlue 2-body forces V18S. Pieper B.Wiringa J Carlson, et al.Sherrill EBSS 2015, Slide 25NN potentialNN + NNN potentialSlide26
Key information from rare isotopes
Neutron rich nuclei were key in determining the isospin dependence of 3-body forces and the development of IL-2R from UIXNew data on exotic nuclei continue to lead to refinements in the interactionsSherrill EBSS 201526NN + improved NNN potentialProperties of exotic isotopes are essential in determining NN and NNN potentialsS. Pieper B.Wiringa, et al.Slide27
Importance of 3N forcesNuclear Equation of State – Lectures by S
. Yennello (Texas A&M) Neutron Stars – Lecture by J. Piekarewicz (FSU) Key ingredient in understanding neutron stars neutron star massesHalf-life of 14C (Maris, Navratil et al. PRL), structure of calcium isotopes (Wienholtz et al. Nature), etc.Sherrill EBSS 201527S. Gandolfi
et al., PRC85, 032801 (2012)
Nazarewicz
et al. Slide28
The Road Map: Understanding the Stability of Atomic Nuclei - A.
Volya (FSU) Step 1: Use ab initio theory and study of exotic rare isotopes to determine the interactions of nucleons in light nuclei and connect these to QCD by comparison to lattice calculations of NN and NNN forcesStep 2: For mid-mass nuclei use configuration interaction models. The degrees of freedom and interactions must be determined from exotic nucleiStep 3: Use density functional theory to connect to heavy nuclei. Exotic nuclei help determine the form and parameters of the DFT. Sherrill EBSS 201528The last step is the one that may answer the question of the limits of nuclei.Slide29
Stability of Magic Nuclei
Sherrill EBSS 201529Harder to exciteSlide30
Stability of Magic Nuclei
Sherrill EBSS 2015, Slide 30Harder to excite20 protons16 protons14 protonsSlide31
Surprise: Changing Magic Numbers
Sherrill EBSS 201531Harder to exciteReason: A tensor force that depends on angular momentum and isospin (Otsuka et al.)Slide32
New Physics from Mass Model Comparison to Data – Lecture M. Redshaw (CMU)
J. Duflo, A.P. Zuker, Phys. Rev. C52 (1995) R23Shell Model Based MEDZ – MEAME2003HFB-14: Hartree-Fock-Bogoliubov w/delta pairing forceS. Goriely, M. Samyn, J.M. Pearson, Phys. Rev. C75 (2007) 064312 MEHFB14 – MEAME2003
ME = (Actual mass – A u
)
x
931.5
MeV/u
u
= atomic mass unit (931.5
MeV
)
More bound than data
Less bound than data
www.nuclear
masses.org
Sherrill EBSS 2015
32Slide33
Weakly bound isotopes have unique features
Sherrill EBSS 201533220RnHaloTanihata PRL1985SkinTanihata PLB1992
11Li
80
Ni
Large neutron skins
Modified mean field
Resonance properties
New
Science:
Pairing in low-density material, new tests of nuclear models, open quantum system, interaction with continuum states -
Efimov
States - Reactions
protons
neutrons
“Normal”Slide34
New insight and physics from extreme halos and skinsT
Example: 42Mg (Predicted to be produced at 10 atoms/day) Theory - 100 keV Sn BA BrownSherrill EBSS 201534Slide35
Limits of the Heaviest Nuclides – Lectures by M.
Stoyer (LLNL) Sherrill EBSS 2015 35W. NazarewiczSlide36
Half-lives of Superheavy Elements
Sherrill EBSS 201536Symbols: exp. valuesLines calc. Sobiczewski & Smolanczuk1 year
W. NazarewiczSlide37
One of the Challenges – How many elements?
Sherrill EBSS 201537- P. Pyykkö: Phys. Chem. Chem. Phys. 13, 161-168 (2011) “Half of chemistry is undiscovered.”- Another view – above Z=122 all chemistry is the same due to relativistic effects- For stability of Z>120 see also Jachimowicz, Kowal, Skalski, PRC 83 (2011)Claims for up to Z=118, but much beyond requires theory – application of Density Functional TheoryW. NazarewiczSlide38
Some Cool QuestionsIs there a standard model for nuclear structure and what is it? Are there forces and interactions beyond this nuclear standard model we will find in nuclei?
How many elements are possible? What is the extent of the isotopes of these elements?How good is the approximation of neutrons and protons in the nucleus?Sherrill EBSS 2015 38Slide39
Abundances are inferred from stellar absorption spectra
Stellar absorption spectraNot all stellar absorption spectra of the same surface temperature are identicalSherrill EBSS 201539 T=4800 K; elements like our sunT=4700 K; only 1/10,000 heavy elementsIntensity (relative)
Intensity (relative)
old star
recently formed starSlide40
One of the Challenges – Origin Elemental Abundances in our Solar SystemLectures by
J. Blackmon (LSU)Stars are mostly made of hydrogen and helium, but each has a unique pattern of other elementsThe abundance of elements tell us about the history of events prior to the formation of our sunThe plot at the right shows the composition in the visible surface layer of the Sun (photosphere)How were these elements created prior to the formation of the Sun?Sherrill EBSS 201540
Asplund, M.,
Grevesse
, N.,
Sauval
, A.J., Scott, P.:
Annu
. Rev. Astron.
Astrophys
. 47, 481 (2009)Slide41
Evolution of Elemental Abundances
Sherrill EBSS 201541
Plots: M.
Weischer
NDU
Data from sky surveys and high resolution spectra and meteoritic compositionSlide42
New data on elemental abundances: Surveys and Large Aperture Telescopes
The measurement of elemental abundances is at the forefront of astronomy using large telescopesLarge mirrors enable high resolution spectroscopic studies in a short time (Subaru, Hubble, LBT, Keck, …)Surveys provide large data sets (SDSS-III, RAVE, LAMOST, SkyMapper, LSST…)Future missions: JWST - “is specifically designed for discovering and understanding the formation of the first stars and galaxies, measuring the geometry of the Universe and the distribution of dark matter, investigating the evolution of galaxies and the production of elements by stars, and the process of star and planet formation.”Sherrill EBSS 201542HubbleSpaceSUBARUSlide43
Chemical History of the Universe – the Fossil Evidence of the First Stars
By measuring the differences we learn about the history of the starBarium (Ba) in early stars must be made differently from Iron (Fe)See Aoki et al. SCIENCE 345 (2014) for a recent discussionComplex problem; nuclear physics is one partSherrill EBSS 201543HERES Survey – Barklem et al. (2005)
Sun [
Ba
/Fe] = [Fe/H] = 0Slide44
Simulation of Solar System Abundances
Sherrill EBSS 201544Timmes, Woosley, Weaver Astro. Journal 1995Success ! ? Note above A=72 we can’t modelParameters: Supernovae type Ia and II
Number (77 supernovae with M
s
11-40
M
sun
)
Progenitor mass distributions
Age of the galaxy
…
Results:
SN rate1/3 comes from type
Ia
They reproduce measured
7
Li abundance
metalicity
vs. time etc. Slide45
Nuclear Physics Discoveries Are an Essential Part of this Revolution
Sherrill EBSS 201545Adapted from Frank Timmes and H Schatzrp-process
p-process
r-process
Neutron star crust
process
Supernova EC process
s-process
i-process
n
p
-process
Stellar fusion
i
-process
(Cowan & Rose Ap. J.)
nuclear uncertainties lead to factor of 200 uncertainty in abundances near N=82 (MG
Bertolli
et al., arXiv:1310.4578)Slide46
Tests of Nature’s Fundamental Symmetries – Lectures P. Mueller (ANL)
Angular correlations in β-decay and search for scalar currentsMass scale for new particle comparable with LHC6He and 18Ne at 1012/sElectric Dipole Moments225Ac, 223Rn, 229Pa (30,000 more sensitive than 199Hg; I > 1010/s)Parity Non-Conservation in atoms
weak charge in the nucleus (francium isotopes; 109
/s)
Unitarity
of CKM matrix
V
ud
by super allowed Fermi decay
Probe the validity of nuclear corrections
e
γ
Z
212
Fr
Sherrill EBSS 2015
46
Adapted from
G
SavardSlide47
“Most of the isotopes in use today in practical settings were developed as long as 50 years ago. With few exceptions (e.g.,
82Sr and 90Y) there are no new products or services that use isotopes developed in the past 20 years. Without the availability of research isotopes, it is not possible to develop new science or new applications based on isotopes. This problem is extreme in the case of accelerator isotopes …”Subcommittee FindingIsotopes for the Nation's FutureNSAC Long Range Plan Study 2008Next Generation Facilities Will Provide Isotopes Needed for Applications – Lectures by E. McCutchan (BNL)
Next generation rare isotope facilities can provide isotopes for applied science while serving forefront nuclear research
FRIB is designed to provide fast access to a broad range of new isotopes for research
Sherrill EBSS 2015
47Slide48
Targeted Cancer Therapy
Modern targeted therapies in medicine take advantage of knowledge of the biology of cancer and the specific biomolecules that are important in causing or maintaining the abnormal proliferation of cellsThese radionuclides have been relatively difficult to get in sufficient quantities. The short-lived alpha emitters are particularly in demand, especially 225Ac, 213Bi, and 211At.Pairs (theragnostic), e.g., 67Cu (treatment) and 64Cu (dosimetry) are particularly interestingFRIB can parasitically supply demand for many isotopesSherrill EBSS 201548A Long Range Plan , NSACIS 2015Slide49
Research Papers Based on 68Ga
Sherrill EBSS 201549Nuclear and Radiochemistry ExpertiseUS National Academies Press(2012)Slide50
Overview of the 2015 Exotic Beam Summer School –
Dream TeamSpeaker Topic A. Volya (FSU) Nuclear Structure (Theory) M. Thoennessen (MSU/NSCL) Exotic Nuclei (Experiment) J. Piekarewicz (FSU) Neutron StarsS. Yennello (Texas A&M) Nuclear Reactions (Experiment) J. Blackmon (LSU) Nuclear
Astrophysics (Experiment)
P
. Mueller (ANL)
Fundamental
Symmetries
M.
Redshaw
(CMU)
Precision Nuclear Masses
M. Couder (Notre Dame)
Beam
Optics
B. Kay (ANL)
Transfer
reaction experiments
J.M
.
Allmond
(ORNL)
Gamma-spectroscopy
methods
M. Stoyer (LLNL)
Super-heavy
Elements
E.
McCutchan
(BNL)
Nuclear
Data
Sherrill EBSS 2015
50Slide51
Summary and Perspective - Our Challenges
Develop a comprehensive model of atomic nuclei – How do we understand the structure and stability of atomic nuclei from first principles? Understand the origin of elements and model extreme astrophysics environments Use of atomic nuclei to test fundamental symmetries and search for new particles (e.g. in a search for CP violation) Search for new applications of isotopes and solution to societal problemsSherrill EBSS 201551You have a good chance to be the people who meet these challenges.Slide52
Backup SlidesSherrill EBSS 2015
52Slide53
Overlap of Nucleons and Their Potential
What is the nature of the “hard-core” repulsion in the nuclear force?Where does the nature of this repulsion show up in nuclear structure?Sherrill EBSS 201553N. Ishii, S. Aoki, T. Hatsuda, Phys. Rev. Lett. 99, 022001 (2007)Slide54
However…Are Nucleons Modified in the Nuclear Medium? Maybe YesEMC “European
Muon Collaboration” Effect circa 1983, CERNJ.Seely, et al, "New Measurements of the EMC Effect in Very Light Nuclei“ PRL 103 (2009) 202301Sherrill EBSS 2015 54Slide55
Short Range Correlations Show a Preference for NP vs PP Pairs
Sherrill EBSS 2015 55This is understood as a result of the tensor part of the nuclear force.Slide56
Observation: EMC Effect is Correlated with SRCN. Formin
et al. , PRL 108 (2012) 092502Sherrill EBSS 201556Slide57
A Voyage of Discovery
Sherrill EBSS 201557
FRIB
has
a chance to make something like 4500 isotopes, or 80% of all the ones possible for Z<92.
This process will be a voyage of discovery!