High energy density nuclear physics at UC Berkeley, LLNL, and LBNL

Karl van Bibber & Lee Bernstein

NIF

HFNG

88” A Bay Area collaboration has formed to study Nuclear Plasma Interactions and related phenomena Primary tools are NIF and other Laser HED platforms Supporting measurements and instrument development at the LBNL 88” cyclotron, and the UC Berkeley HFNG We acknowledge funding by the UC Office of the President A major proposal for a UC HED S&T Center involving four campuses & three labs has just been submitted

Team  HFNG  UC  Berkeley  Ka-­‐Ngo  Leung  Cory  Waltz  Leo  Kirsch  Jay  James  Karl  van  Bibber  Keeton  Ross  Joe  Labrum  BGC  Paul  Renne  Tim  Becker  

LLNL  Lee  Bernstein  

LBNL  Rick  Firestone  

MSU/UMass  Lowell  Andy  Rogers  

The  HFNG  primarily  designed  for  39Ar/40Ar  daLng  technique  for  geochronology  and  paleochronology  –  requires  39K(n,p)39Ar        Our  design  enables  both  2.45  MeV  and  thermal  neutrons,  either  internal  to  the  target  or  in  an  external  beamline      

Background  of  the  High  Flux  Neutron  Generator  (HFNG)

HFNG  designed  by  Ka-­‐Ngo  Leung  for  the  Berkeley  Geochronology  Center  Supported  by  NSF  ARRA  funding  Expected  Neutron  Flux  (over  4π)  ≈  5  ×  1011  neutrons/sec            

D-­‐D  Fusion  ReacLon:    

Deuteron   Deuteron  

3He  Neutron  

D    +    D   →  3He   +          n  

Q  =  2.45  MeV  

Cooling  ConnecLons  

Target  

RF  Ion  Source  

Matching  networks  for  RF  

Turbopump   Major  components:      120  kV,  200  A  Power  supply    30  A  RF  Generators    Impedance  Matching  Networks  for  RF    Turbopump    Cooling  System    Poly  Shielding  

The  Generator

Shielding  

Opera=on

RF  Ion  Source  

RF  Ion  Source  

Target  

Deuterium  Injected  

RF  ON  

RF  ON  

High  Voltage  ON  

Deuterium  imbeds  into  target  

Enough  deuterium  imbedded  in  target  for  collisions  to  occur  

D-­‐D  Fusion!  

First  neutrons  were  produced  on  July  25,  2014    115In  (n,n’)  115mIn    (  4.49  h,  336  keV  γ )  

•    100  kV  anode  voltage            •    1  mA  ion  current  •    (0.2-­‐2)  ×  108  n/sec  

The  Indium  disk  used  to  measure  the  neutron  flux  from  HFNG  was  the  idenKcal  foil  which  measured  the  first  neutrons  from  NIF  in  2010    

Next steps: suppression of back-streaming electrons to enable current to reach goal of ~ 1 A & thus ~ 1011 n/sec Strategy for suppression involves both permanent magnets in the anode, and a ‘shroud’ to capture electrons Movie (right): Plasma without magnets & graphite shield Movie (left): Plasma with magnets & graphite shield We can now run with ~ 4 mA A full shield is being designed with the assistance of Comsol modeling

Our collaboration is pursuing a multi-component program to measure nuclear-plasma interactions in HED plasmas

Mau Chen, Andrea Kritcher, Bob Heeter, Darren Bleuel, Dawn Shaughnessy, Carol Velsko, Bill Cassata, Laura Hopkins, K. Moody, N. Gharibyan, D.H.G. Schneider

LLNL

Bethany Goldblum, Brian Daub, Karl Van Bibber, Jasmina Vujic, Joshua Brown, Nick Brickner, O. Clamens, O. Nunez

University of California - Berkeley

Vincent Meot, Gilbert Gosselin, Pascal Morel, Phillipe Franck, Charles Reverdin CEA-DAM

A. Yasunobu, M. Nakai, H. Azechi

ILE-Osaka

Lawrence Livermore National Laboratory 9  This work was performed under the auspices of the U.S. DOE by Lawrence Livermore National Laboratory

under contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC

Classes of Nuclear Plasma Interactions (NPI)

10  

Nucleus  HEDP  

Photons  

Photo-absorption Time Reverse: γ-ray decay

Photons  

           

N N*

   

efree ebound

Atomic-nuclear (electron) interactions NEEC, NEET, IES*

Time Reverse: IC-decay

Atom  electrons   photons  

N N*

Lawrence Livermore National Laboratory 10  This work was performed under the auspices of the U.S. DOE by Lawrence Livermore National Laboratory

under contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC

NPI-induced population of low-lying excited states changes the spin of the compound nucleus leading to alterations in neutron capture rates in stellar plasmas

*Bao & Kappeler At. Dat. Nucl. Dat. Tables 76, 70–154 (2000)

SEF kT( ) = σ HEDP

σGS

=2Ji +1( )σ Ex = Ei( )

i=0

∞

∑ e−Ei /kT

σGS 2Ji +1( )i=0

∞

∑ e−Ei /kT

AZ A+1Z

Sn

NEEC/T  

These rates remain entirely unmeasured

0 2 4 6 8 10

Excitation energy E* (MeV)

10!4

10!3

10!2

10!1

100

101

102

103

104

LIfe

time

of s

ingl

e CN

sta

te (p

s)

J/pi= 0.0+ J/pi= 1.0+ J/pi= 2.0+ J/pi= 3.0+ J/pi= 4.0+ J/pi= 5.0+ J/pi= 6.0+ J/pi= 7.0+ J/pi= 8.0+ J/pi= 9.0+ J/pi= 10.0+ J/pi= 11.0+ J/pi= 12.0+ J/pi= 13.0+ J/pi= 14.0+ J/pi= 15.0+ J/pi= 16.0+ J/pi= 17.0+ J/pi= 18.0+ J/pi= 19.0+

Energy (MeV) 0 2 4 6 8 10

Excitation energy E* (MeV)

10!4

10!3

10!2

10!1

100

101

102

103

104

LIfe

time

of s

ingl

e CN

sta

te (p

s)

J/pi= 0.0+ J/pi= 1.0+ J/pi= 2.0+ J/pi= 3.0+ J/pi= 4.0+ J/pi= 5.0+ J/pi= 6.0+ J/pi= 7.0+ J/pi= 8.0+ J/pi= 9.0+ J/pi= 10.0+ J/pi= 11.0+ J/pi= 12.0+ J/pi= 13.0+ J/pi= 14.0+ J/pi= 15.0+ J/pi= 16.0+ J/pi= 17.0+ J/pi= 18.0+ J/pi= 19.0+

Higher spin states are less Likely emit neutrons

Life

time

(ps)

0 2 4 6 8 10

Excitation energy E* (MeV)

10!4

10!3

10!2

10!1

100

101

102

103

104

LIfe

time

of s

ingl

e CN

sta

te (p

s)

J/pi= 0.0+ J/pi= 1.0+ J/pi= 2.0+ J/pi= 3.0+ J/pi= 4.0+ J/pi= 5.0+ J/pi= 6.0+ J/pi= 7.0+ J/pi= 8.0+ J/pi= 9.0+ J/pi= 10.0+ J/pi= 11.0+ J/pi= 12.0+ J/pi= 13.0+ J/pi= 14.0+ J/pi= 15.0+ J/pi= 16.0+ J/pi= 17.0+ J/pi= 18.0+ J/pi= 19.0+

Lawrence Livermore National Laboratory 11  This work was performed under the auspices of the U.S. DOE by Lawrence Livermore National Laboratory

under contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC

We have attempted to observe NPI-induced population of low-lying nuclear states through the observation of prompt γ-rays in a HEDP formed using a high energy laser

60 beams 30 kJ at 3ω Variable pulse shape P ≥ 60TW

The Omega laser at LLE  

Lawrence Livermore National Laboratory 12  This work was performed under the auspices of the U.S. DOE by Lawrence Livermore National Laboratory

under contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC

The experiments at Omega were designed to directly detect NEEC decay in hohlraum targets

169Tm hohlraum (10 μm thick)"

38 drive beams"

1 ns laser pulses were used to heat the interior of the Tm hohlraum to > 5 keV.

-Tm atoms undergo NEEC to 8.41 keV excited state closely matches L-shell e- energies

-gamma decay is measured 2-4 ns later using Omega x-ray diagnostics 169Tm

3/2+

1/2+ 0

8.4 keV 4.1 ns

Lawrence Livermore National Laboratory 13  This work was performed under the auspices of the U.S. DOE by Lawrence Livermore National Laboratory

under contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC

8-9 keV γ-rays can be detected with standard crystal x-ray spectrometers at Omega

High collection efficiency Bragg crystal allows γ’s to be seen above x-ray background

F=12.5 cm!

XRFC & FILM!

Source!

θBragg=12o!

Highly Oriented Pyrolytic Graphite (HOPG) crystal

Spectral Range: 6.8-12 keV Reflectivity ~3 mrad Solid angle Ωdet~5×10-5

Lawrence Livermore National Laboratory 14  This work was performed under the auspices of the U.S. DOE by Lawrence Livermore National Laboratory

under contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC

Our first LLE experiments in 2012 produced confusing results: Did we observe NEEC or atomic metastable states in 169Tm?

M.  Chen  simulaKons  

NEEC  rate  in  blowoff  plasma  

Detected late time spectrum

Met

asta

ble

st

ate N

EE

C?

?  

Au HED plasmas: M.B. Schneider et al, Phys. Plasmas 13, 112701 (2006)

Lawrence Livermore National Laboratory 15  This work was performed under the auspices of the U.S. DOE by Lawrence Livermore National Laboratory

under contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC

On May 7 we revisited this approach at Omega using 187Os (test case), 192Os (control) and 169Tm half-raums

The control allows us to separate nuclear from atomic physics effects:

Half-raum with washer reduces blow-off plasma location ambiguity.

187Os  

3/2-­‐  

1/2-­‐  0  keV  

9.76  keV  

192Os  

2+  

0+  0  keV  

206  keV  

NEEC  

γ  (2.4ns)  

Th/Os  plum

e  

Ti  

Control  

t  =  3  ns  

t  =  4  ns  

t  =  5  ns  

t  =  6  ns  

169Tm  

The 2012 “phantom” is gone

10-5

0.0001

7000 7500 8000 8500 9000 9500 1 104 1.05 104

Osmium 187 @ 3nsOsmium 192 @ 3ns

Arbitra

ry Un

its

E (eV)

10-6

10-5

0.0001

7000 7500 8000 8500 9000 9500 1 104 1.05 104

Osmium 187 @ 4nsOsmium 192 @ 4ns

Arbitra

ry Un

its

E (eV)

10-6

10-5

0.0001

7000 7500 8000 8500 9000 9500 1 104 1.05 104

Osmium 187 @ 5nsOsmium 192 @ 5ns

Arbitra

ry Un

its

E (eV)

Os  

Lawrence Livermore National Laboratory 16  This work was performed under the auspices of the U.S. DOE by Lawrence Livermore National Laboratory

under contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC

The candidate peak is still there

AZ A-1Z

Sn

g m

Isomer de-excitation can be used to observe NPIs on excited states in HED plasmas as well*

*G. Gosselin & P. Morel Phys. Rev. C 70 064603 (2004)

X keV t1/2 > 20 ps

AZ

X+ΔE keV

i

f

Ideal case

Γf→i ≈ Γf→g

g

e- γ

Ground  State  

Isomer  

Ground  State  

Isomer  

Via discrete states Via the quasi-continuum

Lawrence Livermore National Laboratory 17  This work was performed under the auspices of the U.S. DOE by Lawrence Livermore National Laboratory

under contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC

The National Ignition Facility (NIF) at LLNL provides an HEDP with 20x longer confinement times than LLE

192  beams  1.8  MJ  at  3ω  Variable  pulse  shape  (20ns)  P  ~  500TW  

Up  to  1016  neutrons  which  can  be  used  to  make  

isomers  

Lawrence Livermore National Laboratory 18  This work was performed under the auspices of the U.S. DOE by Lawrence Livermore National Laboratory

under contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC

Our programs also includes a component focused on NPI-induced reactions taking place on highly-excited states altering the population of isomers

AZ

A+1Z

Sn

Bf

The situation could be even more complicated if fission is an open channel (e.g., the r-process)

NEE*/NRF

Current  Assum

pLon  

Sn+En

0 2 4 6 8 10

Excitation energy E* (MeV)

10!4

10!3

10!2

10!1

100

101

102

103

104

LIfe

time

of s

ingl

e CN

sta

te (p

s)

J/pi= 0.0+ J/pi= 1.0+ J/pi= 2.0+ J/pi= 3.0+ J/pi= 4.0+ J/pi= 5.0+ J/pi= 6.0+ J/pi= 7.0+ J/pi= 8.0+ J/pi= 9.0+ J/pi= 10.0+ J/pi= 11.0+ J/pi= 12.0+ J/pi= 13.0+ J/pi= 14.0+ J/pi= 15.0+ J/pi= 16.0+ J/pi= 17.0+ J/pi= 18.0+ J/pi= 19.0+

Energy (MeV) 0 2 4 6 8 10

Excitation energy E* (MeV)

10!4

10!3

10!2

10!1

100

101

102

103

104

LIfe

time

of s

ingl

e CN

sta

te (p

s)

J/pi= 0.0+ J/pi= 1.0+ J/pi= 2.0+ J/pi= 3.0+ J/pi= 4.0+ J/pi= 5.0+ J/pi= 6.0+ J/pi= 7.0+ J/pi= 8.0+ J/pi= 9.0+ J/pi= 10.0+ J/pi= 11.0+ J/pi= 12.0+ J/pi= 13.0+ J/pi= 14.0+ J/pi= 15.0+ J/pi= 16.0+ J/pi= 17.0+ J/pi= 18.0+ J/pi= 19.0+

Whether  this  happens  depends  on  τ(J),  σNPI,  and  Φe,γ

Life

time

(ps)

0 2 4 6 8 10

Excitation energy E* (MeV)

10!4

10!3

10!2

10!1

100

101

102

103

104

LIfe

time

of s

ingl

e CN

sta

te (p

s)

J/pi= 0.0+ J/pi= 1.0+ J/pi= 2.0+ J/pi= 3.0+ J/pi= 4.0+ J/pi= 5.0+ J/pi= 6.0+ J/pi= 7.0+ J/pi= 8.0+ J/pi= 9.0+ J/pi= 10.0+ J/pi= 11.0+ J/pi= 12.0+ J/pi= 13.0+ J/pi= 14.0+ J/pi= 15.0+ J/pi= 16.0+ J/pi= 17.0+ J/pi= 18.0+ J/pi= 19.0+

?  

Lawrence Livermore National Laboratory 19  This work was performed under the auspices of the U.S. DOE by Lawrence Livermore National Laboratory

under contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC

A NIF experiment using this approach is planned using a 134Xe-doped exploding pusher to make 133mXe and 133gXe in and out of a HEDP

We maximize both neutron flux and plasma density by placing a 134Xe dopant nuclei in a direct-drive target

…plus a “control” sample outside the plasma in a sample positioner 50cm from the target

Glass/CH pusher (10 µm)

Fusion neutrons interact with Xe on way out of target

DT gas 0.03% 134Xe

     

5.243 d 11/2-

3/2+

133Xe 2.19 d

All of the Xe gets hots

50 cm

None of the Xe gets hots

RDIGS ≡

NRAGS133mXe

NRAGS133g Xe

NDIM133mXe

NDIM133g Xe

≠1→ NPI

Lawrence Livermore National Laboratory 20  This work was performed under the auspices of the U.S. DOE by Lawrence Livermore National Laboratory

under contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC

The radiochemical team at NIF has shown that it can collect radioactive Xenon from exploding pushers with high efficiency

From NIF chamber turbo pumps

> 50% of gaseous material in NIF chamber can be retrieved

Exploding pusher

0.03% Xenon

2 mm

Lawrence Livermore National Laboratory 21  This work was performed under the auspices of the U.S. DOE by Lawrence Livermore National Laboratory

under contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC

≥100 µm metal foil

197Au beam

≈1 µm 13C target

196,198Au

Excited 198/196Au* residuals made via binary transfer from 13C recoils into a Bismuth foil “plasma target”

In the “close” target NEEC can occur on quasi-continuum states.

In the “far” target, Au has decayed to ground state or isomer, and NEEC will occur on these states.

A “beam-foil” experiment is scheduled for 10/14 at LBNL to try and observe NPIs on highly excited state in 196Au via isomer de-excitation

+  

196,198Au***

Lawrence Livermore National Laboratory 22  This work was performed under the auspices of the U.S. DOE by Lawrence Livermore National Laboratory

under contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC

130  MeV  13C  

Gold Target Layers (1 micron)

Aluminum Degrader Foils (25 microns)

Gold Monitor Foil

Aluminum Stopping Foils

Maximum m/g ratio occurs at 8.5 MeV/nucleon.

In preparation for this experiment we performed an excitation function measurement that has produced a publication worthy result in its own right

Lawrence Livermore National Laboratory 23  This work was performed under the auspices of the U.S. DOE by Lawrence Livermore National Laboratory

under contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC

Step  1  • Make  radioacLve  gold  using  the  RCNP  AVF  cyclotron  via  natPt(p,xn).  • Proton  Beam:  20  MeV,  1μA  (min),  1.5cm  diameter  

Step  2  • Count  acLvity  of  radioacLve  targets  •  Isotope:  194Au;  Peak  Energy:328.464keV;  Peak  Intensity:  60.4%  

Step  3  • Collect  debris  with  our  models  in  GEKKO  XII  Target  Chamber  • Various  models,  with  different  sizes  and  materials  

Step  4  • Perform  chemistry  to  prepare  a  sample  for  counLng  using  HPGe  detector  

Step  5  • Count  again  and  compare  with  the  results  in  Step  3  to  obtain  the  collecLon  efficiency  

We are now planning to develop enhanced debris collection techniques at ILE-Osaka using radioactive Au nuclei produced at the RCNP cyclotron

GEKKO chamber

Debris Collector

RCNP collimator

Many thanks to the team at ILE, including Dr. Arikawa Yasunobu!

Lawrence Livermore National Laboratory 24  This work was performed under the auspices of the U.S. DOE by Lawrence Livermore National Laboratory

under contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC

Summary

1 A multi-institutional collaboration has been assembled at and around UCB 1  To pursue neutron-induced nuclear science measurements 2  To study the elusive topic of nuclear-plasma interactions

2 We are pursuing a multi-component approach to try and observe the elusive phenomena of NPIs:

1  On nuclear ground states using Laser-driven HEDPs at Omega in 169Tm and 187Os 2  On excited nuclear states via isomer de-excitation in 133Xe at NIF 3  On excited states via isomer de-excitation in 196,198Au using the LBNL 88-Inch cyclotron.

3 We are also working to develop enhanced debris collection at ILE-Osaka 1  This is the 1st step toward using a combination of long- and short-pulse lasers to observe NPIs

Thanks for your attention!

Lawrence Livermore National Laboratory 25  This work was performed under the auspices of the U.S. DOE by Lawrence Livermore National Laboratory

under contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC