Transcript Document

Triangle
Universities
Nuclear Laboratory
A Department of Energy Center of Excellence
Three-University Consortium in the Research Triangle Area
• Duke University, Durham
• North Carolina State University, Raleigh
• University of North Carolina, Chapel Hill
Mission
1) To contribute to advancing the frontiers of nuclear physics research
and to
the application of nuclear physics in response to national needs;
and
Web: http://www.tunl.duke.edu
2) To educate the next generation of nuclear physicists
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TUNL: Faculty, Researchers and Staff
Faculty (15 tenured/tenure-track)
Duke University
NC State University
UNC – Chapel Hill
M. W. Ahmed1
H. Gao
C.R. Howell
W. Tornow (Emeritus)
H.R. Weller (Emeritus)
Y.K. Wu
D.G. Haase
P.R. Huffman
R. Golub
C.R. Gould
J.H. Kelley (Research)
G.E. Mitchell (Research)
A.R. Young
A.E. Champagne
T.B. Clegg
R. Henning
C. Iliadis
H.J. Karwowski
J.F. Wilkerson
Researchers
 42 graduate students (12+13+17)
 18 postdocs (9+5+ 4), including 2 accel. physics
 5 research scientists (2 nuclear physicists + 3 accelerator physicists)
Staff




3 Administrative staff
5 R&D Engineers
5 technicians
2 accelerator operators/technicians
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TUNL: Associated Universities
(primarily undergraduate serving)
James Madison University
North Carolina A&T State University (HBCU in Greensboro, NC)
North Carolina Central University (HBCU in Durham, NC)
North Georgia College and State University
Penn State Altoona
University of Connecticut, Avery Pt.
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TUNL Research Community
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Nuclear Physics at TUNL
.
Nuclear Structure (few-nucleon,
collective excitations, many-body structure, nucleon structure)
NS6: … explore the description of many-body symmetries and collective modes, and their relationship to effective forces.
HP10: … studies of the structure and dynamics of light nuclei based on two-nucleon and many-nucleon forces and lattice QCD …
Faculty: Ahmed, Clegg, Gao, Howell, Karwowski, Kelley, Mitchell, Tornow, Weller
Facilities/Projects: TUNL accelerator facilities, KURF, LANL-DANCE
Nuclear Astrophysics (classical novae, explosive nucleosynthesis)
NA4: Reduce uncertainties of the most crucial stellar evolution nuclear reactions (e.g. 12C(α,γ)16O) …, and others (e.g. the MgAl cycle)
....
NA10:
Measure
or constrain
key nuclear reaction
ratesKelley,
to improve
accuracy
of astrophysical models of novae and X-ray bursts …
Faculty:
Ahmed,
Champagne,
Clegg,
Iliadis,
Weller
Facilities/Projects: TUNL accelerator facilities
Fundamental Symmetries (CP violation, neutron and nuclear b decay)
FI4: Make … improvements in measurements of neutron and nuclear beta-decay to constrain physics beyond the standard model.
FI15: Obtain … an experiment to extend the limit on the electric dipole moment of the neutron by two orders of magnitude
Faculty: Ahmed, Haase, Huffman, Gao, Golub, Gould, Young
Facilities/Projects: nEDM-SNS, LANL-UCNA, UCN-PULSTAR, TRImP- KVI
Neutrino Physics (0nbb, direct mn, n oscillations)
FI6: Improve the sensitivity of the direct neutrino mass measurements to 0.35 eV.
FI14: Extend the sensitivity of searches for neutrinoless double-beta decay in selected nuclei by a factor of ten in lifetime
Faculty: Henning, Karwowski, Tornow, Wilkerson, Young
Facilities/Projects: MAJORANA Demo, KATRIN, KURF, KamLAND
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TUNL: Publications
Jan. 2010 – Apr. 2013
Nuclear
Structure
& Fewnucleons
Total
Hadron
Structure
Journal papers
105
4
35
23
11
21
5
6
Letter papers
16
1
8
0
3
4
0
0
121
5
43
23
14
25
5
6
Type
Total
Nuclear
Astrophysics
Fundamental
Symmetries
Neutrinos
Accel.
Physics
Applied
Research at TUNL highly collaborative:
Out of 121 publications, 52 were co-authored researchers from at least two of
the TUNL consortium institutions
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TUNL: Graduate EducationTUNL
About 8% (5.6 out of 70 annually) of the nation’s PhDs in
experimental nuclear physics are educated at TUNL
270 Ph.D. degrees awarded since inception of TUNL
Most recent 10 years: Total PhDs = 56
PhD degrees awarded from Jan. 2010 – April 2013 = 24
Industry/s
cience, 2
Faculty,
1
industry/n
onscience, 4
Postdoc,
15
National
Lab/Scien
tist, 2
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DOE/ONP Support Structure for TUNL
DUKE
NC State Univ.
DOE/ONP/LE, DOE/ONP/ME,
DOE/ONP/LE
DOE/ONP/LE
TUNL facility
operations,
technical support,
administrative support,
materials and supplies,
and
research
instrumentation
Univ. NC
DOE/ONP/LE
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TUNL: Accelerator Facilities
High Intensity Gamma Source (HIgS)
Eg = 1 – 100 MeV
Linear and circular polarized beams
1.2 GeV Storage Ring FEL
Delivering up to 103 g/s/eV on
target, HIgS is the most intense
accelerator-driven g-ray source
in the world
Laboratory for Experimental Nuclear Astrophysics
World’s
highest current proton beam
(LENA)
for nuclear astrophysics research
Tandem Laboratory:
light-ion and pulsed neutron beams
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Studies of Strongly Interacting Matter at HIgS
From 2007 Nuclear Science LRP
Compton Scattering
nucleon electric and magnetic polarizabilities
nucleon spin polarizabilities
GDH Sum Rule
2H
3He
Photo-pion Production
Few-nucleon Systems
photodisintegration
Nuclear Structure
NRF, (g,g’), Compton
Scattering
(g,n) reactions, photofission
Nuclear Astrophysics
(g,a), (g,n) reactions
Milestones:
NS6: collective modes in many-body nuclei
HP10: ab initio microscopic studies
NA4: 16O(g,a)
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Laboratory for Experimental Nuclear Astrophysics (LENA)
For details about the LENA accelerators see,
Milestone
NA4: stellar evolution, e.g., 14N(p,g)
NA10: novae and X-ray bursts, e.g.,
29Si(p,g)
and 17O(p,g)
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Search for Physics Beyond the Standard Model
Majorana Demonstrator
neutron EDM at SNS
TUNL Faculty
Ahmed, Gao, Golub, Gould, Haase, Huffman
TUNL Faculty
Henning, Tornow, Wilkerson, Young
• Probes the particle - anti particle nature of the neutrino
• Symmetry breaking - lepton number
• Determination of neutrino mass, insight into the origin
of mass
• Probes new physics (at or beyond LHC scale)
• Matter - antimatter asymmetry
• Would sharply constrain new physics models &
complementary with LHC
• 18 institutions, ~100 collaborators
• Under construction at Sanford Underground
Laboratory, Lead SD
• 21 institutions, ~67 collaborators
• In R&D phase. Will be located at the Spallation Neutron
Source, ORNL
2017
2020
FI14
Extend the sensitivity of searches for neutrinoless
double-beta decay in selected nuclei by a factor of
ten in lifetime
FI15
Obtain initial results from an experiment to
extend the limit on the electric dipole moment of
the neutron by two orders of magnitude
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Summary

Contributing to 8 performance milestones in the nuclear physics program at
NS6: … explore the description of many-body symmetries and collective modes, and their relationship to effective forces.
DOE
HP10: … studies of the structure and dynamics of light nuclei based on two-nucleon and many-nucleon forces and lattice QCD …
NA4: Reduce uncertainties of the most crucial stellar evolution … reactions (e.g. 12C(α,γ)16O) …, and … (e.g. the MgAl cycle) ...
NA10: Measure or constrain key nuclear reaction rates to improve accuracy of astrophysical models of novae and X-ray bursts …
FI4: Make … improvements in measurements of neutron and nuclear beta-decay to constrain physics beyond the standard model.
FI15: Obtain … an experiment to extend the limit on the electric dipole moment of the neutron by two orders of magnitude
FI6: Improve the sensitivity of the direct neutrino mass measurements to 0.35 eV.
FI14: Extend the sensitivity of searches for neutrinoless double-beta decay in selected nuclei by a factor of ten in lifetime

Highly productive (Jan. 2010 – Apr. 2013)
research: published 121 peer review papers (of which 16 were letters)
education: 25 PhD degrees awarded based on research at TUNL
(~10% of U.S. PhD recipients in expt’l nuclear physics over the same period)

Three on-site accelerator facilities with unique capabilities that enable world-class
research
+ HIgS, highest intensity g-ray beam in the world, polarized; basic and applied research
+ LENA, highest current proton beam in the world at energies needed for nuclear
astrophysics
 Playing leadership role in major research projects supported by the ONP at DOE
+ Tandem Lab, mono-energetic pulsed neutron beam; basic and applied research
+ MAJORANA Demonstrator
+ nEDM
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Duke University
Nuclear Structure
and
Nuclear Astrophysics
NTOF Group:
Faculty: C.R. Howell and W. Tornow (emeritus)
Graduate Students: L.C. Cumberbatch1, B. Fallin2, S.W. Finch, F. Friesen, D. Ticehurst3
Postdocs: M. Bhike4, J.H. Esterline,
Research Scientists: A.S. Crowell
Capture Group:
Faculty: M.W. Ahmed5, H.R. Weller (emeritus), Y.K. Wu
Graduate Students: A. Kafkarkou, J.M. Mueller6, W.R. Zimmerman7
Postdocs: D.P. Kendellen8, L.S. Myers2
Accelerator Physics Group:
Faculty: Y.K. Wu
Graduate Students: J. Yan, W. Zhou
Notes:
1.
2.
3.
4.
Partially supported by DOE/BER
Partially supported by DHS/DNDO
UNC graduate student advised by Howell
Supported by DOE/NNSA
5. Joint NCCU-TUNL faculty position; Adjunct faculty appointment at Duke
6. Supported by DOE/SC Grad. Fellowship until Aug. 31, 2013
7. U. Conn. Student advised by Weller
8. Partially supported by North Georgia College and State Univ.
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Nuclear Structure and Nuclear Astrophysics
•Nuclear Structure
o
o
o
nucleon structure
few-nucleon systems
many-body systems
+
+
+
collective modes of excitation
nuclear structure relevant to 0nbb
neutron-induced reactions relevant to 0nbb
•Nuclear Astrophysics
o
o
evolution of massive stars, e.g., the 12C(a, g)16O reaction
big-bang nucleosynthesis, e.g., the 2H(g, n) reaction
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Few-nucleon Systems
Driving Questions:
• What does QCD predict for the features of the interactions of protons and neutrons?
• What governs the transition of quarks and gluons into pions and nucleons?
Contribution: Provide data to guide the development of low-energy effective
theories that connect QCD to the strong interaction in nuclei, e.g., ab
initio few-nucleon calculations that use meson-exchange NN potential
models or NN interactions from low-energy EFT.
Examples of issues:
• Modeling multi-nucleon interactions
• Treatment of meson-exchange currents
• Treatment of Coulomb interactions
2013
NS6
Carry out microscopic calculations of medium mass nuclei with realistic interactions, develop a realistic nuclear
energy density functional for heavy nuclei, and explore the description of many-body symmetries and collective
modes, and their relationship to effective forces
2014
HP10
Carry out ab initio microscopic studies of the structure and dynamics of light nuclei based on two-nucleon and
many-nucleon forces and lattice QCD calculations of hadron interaction mechanisms relevant to the origin of
the nucleon-nucleon interaction.
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Few-nucleon Photonuclear Reactions
Photodisintegration data of 3- and 4-nucleon systems:
• Evaluate overall theoretical treatment of the systems, e.g., ChEFT and mesonexchange NN potential models
• Sensitive to treatments of the Coulomb force
• Sensitive to the treatment of meson-exchange currents (MEC)
• Low sensitivity to 3NFs depends on treatment of MEC
from W. Tornow et al., Phys. Lett. B 702, 121 (2011)
from R. Raut et al., Phys. Rev. Lett. 108, 042502
(2012)
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Accomplishments: Photodisintegration of 3He
New measurements at HIgS resolve discrepancies in total cross section
for two-body photodisintegration of 3He,
W. Tornow et al., Phys. Lett. B 702, 121 (2011)
Faculty: H.J. Karwowski, J.H. Kelley, W. Tornow
Experimental Setup
Eg = 7 – 16 MeV
Pulse-height spectrum
from gas scintillator
Results
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Accomplishments: Photodisintegration of 4He
Discrepancies in total cross section for
two-body photodisintegration of 4He resolved
Faculty: M.W. Ahmed, J.H. Kelley, W. Tornow
Experimental Setup
Eg = 22 – 30 MeV
R. Raut et al.,
Phys. Rev. Lett. 108, 042502 (2012)
W. Tornow et al.,
Phys. Rev. C 85, 061001R (2012)
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Accomplishments: First Measurements of Spin-Dependent Cross Sections for
3He(g,n)pp
First measurements of the Spin-Dependent Double-Differential Cross Sections and the GDH Integrand
from 3He(g,n)pp at Incident Photon Energies of 12.8 and 14.7 MeV, G. Laskaris et al., Phys. Rev. Lett.
(accepted)
Thesis project of Georgios Laskaris
Faculty: M.W. Ahmed, H. Gao, H.R. Weller
Gerasimov-Drell-Hearn (GDH) sum rule
Experimental Setup:



Circularly Polarized Gamma rays at 12.8 and 14.7 MeV
An optically pumped polarized 3He target
Neutron Detector Array
Results
Calc. by Deltuva et al.
(AGS eqns., CDBonn+Delta with
Coulomb)
Calc. by Skibinski et al.
(Faddeev eqns.,
AV18+UIX 3NF, no
Coulomb)
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Plans: Few-nucleon Photonuclear Reactions
Two-body photodisintegration spin-dependent differential and total crossSection measurements of the 3He(g, p)d reaction at 25 and 30 MeV
Faculty: M.W. Ahmed, H. Gao, H.R. Weller
Thesis Student: Georgios Laskaris
Motivation: GDH sum rule on 3He and few-nucleon reaction dynamics
Facility: HIgS
2- and 3-body photodisintegration
contributions to the GDH integrand of 3He
Photo of test setup (April 2013)
Calculations by Deltuva et al.
Status: Proposal submitted to the HIgS 2013 PAC
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Plans: Few-nucleon Photonuclear Reactions
Differential cross-section measurements of two- and three-body
photodisintegration of Triton
Faculty: M.W. Ahmed, C.R. Howell, W. Tornow
Thesis Student: Forrest Friesen
Motivation: few-nucleon reaction dynamics
Facility: HIgS
Status of data
•
•
No differential data
Total cross-section data exist but has
substantial scatter and has discrepancies
above 20 MeV
from W. Schadow and W. Sandhas, Nucl. Phys. A631, 588c (1998)
Proposed measurement at HIgS
at 15 and 25 MeV
Experiment setup: measure momentum of protons and deuteron
Wire chambers
Tritium gas target activity ~ 300
Ci
Gas contained in target cells
with 2.5-mm thick Havar foil
Silicon detectors
80 cm
Status: Proposal submitted to the HIgS 2013 PAC
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Accomplishments: Nucleon Structure
Determined Isoscalar polarizabilites using Compton scattering on 6Li at HIgS
 Compton scattering provides observables important to the development of ab inito calculations of light nuclei
 Sensitive to the isoscalar polarizability of the nucleon, as and bs
L.S. Myers et al., Phys. Rev. C 86, 044614 (2012).
Experimental Setup:
 Circularly Polarized Gamma rays at 60 MeV
 HIGS NaI Detector Array (HINDA)
 Solid 6Li target
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Nuc
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Nuc
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Nuc
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Nuc
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Nuc
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Nuc
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