RIA and the DOE/NNSA National Security Mission

Radiochemistry at RIAAmerican Chemical Society, New Orleans

Michael N. KreislerNational Nuclear Security AdministrationLawrence Livermore National Laboratory

University of Massachusetts AmherstMarch 27, 2003

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NNSA

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Science

• DOE Secretary Abraham and Presidential Science Advisor Marburger:– “Every project must show relevance to National

Security”

• From NNSA’s perspective:– “There is a case to be made for a Rare Isotope

Accelerator”

RIA will allow important Science-Based Stockpile Stewardship measurements that can’t be made easily

any other way3

the specific issues that matter in nuclear weapons

World-class science, with detailed engineering investigations and high-fidelity three-dimensional simulations, can maintain a reliable nuclear weapons stockpile

Dynamic, vital and broad physical science community that engages

•Premise

•Requirement

Stockpile Stewardship Computing & Simulation

High-Energy-Density Physics

HydrodynamicsMaterials, Physical Data, and Microsystems

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Stewardship Goals and RIA

• Measure cross sections and reaction rates on unstable nuclei– Allows neutron flux measurements in environments with

very high instantaneous flux• Conduct detailed studies of fission processes (mass

distributions, lifetimes etc.)• Fill major holes in nuclear data bases• Guarantee a source of low energy nuclear physicists

for the NNSA labs.

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Example of a key SBSS problem

• Determine the neutron energy spectrum, flux, and angular dependence in environments with extremely high instantaneous neutron flux.

• Such fluxes exist in only a few places:– Inside stars– Near an ignited capsule at the National

Ignition Facility– Archival nuclear test data

• Interpreting experimental observations is difficult.

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• To measure the neutrons produced in a mm-sized hohlraum at the center of a 10 m target chamber:– Install foils of various isotopes– Measure daughter products after the implosion– (Often the neutron flux is highly non-symmetric)– Examples: – Foils of 90Zr– Measure 89Zr/90Zr and 88Zr/89Zr

Most of the intermediate cross sections are not measured – RIA is NEEDED!

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Sensitivity Study for Simple Reaction NetworkChange in Isotope Ratio

Reaction For 10% change incross section

For 50% change incross section

89Zr/90ZL88Zr/89Zr 89Zr/90ZrL

88Zr/89Zr90Zr(n,2n)89gZr 7.2% 4.0% 36% 20%

90Zr(n,2n)89m3Zr 1.3% 2.0% 6.5% 10%89Zr(n,2n)88Zr 2.3% 8.4% 11.5% 42%89Zr(n,γ)90m4Zr 4.2% 1.1% 21% 5.5%

89Zr(n,γ)90Zr 3.2% 0.9% 16% 4.5%88Zr(n,γ)89m3Zr 0.2% 3.1% 1% 15.5%

89m3Zr(n,2n)88Zr 0.1% 1.6% 0.5% 8%90m4Zr(n,2n)89Zr 1.0% 0.5% 5% 2.5%

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The Reaction Network

90Zr

89Zr

88Zr

Green: Cross section for sum (g.s + 0.94m) known to 2% for En = 13-15 MeV.Red: Cross section determined by calculation only.

It is important to measure these cross sections accurately from threshold to 20 MeV.

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NNSA and RIA

•Support groups working at RIA

–New Academic Alliances program in NNSA

–LLNL $1 M of equipment to ANL RIB effort

–NNSA to fund groups doing relevant RIA experiments

•Expect NNSA scientists to help design the best experimental program

•Would like to help show a broad interest in RIA from other parts of DOE

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Radiochemistry Facility and Transportation

• Production limits imply shortest half-life of produced species ~ 1 hour

• Will probably wait on order of one hour before trying to handle production products.

• 10 µg of 1 hour half-life isotope implies ~150 C one hour after production run.

• Depending on efficiency of separation and decay products, may besignificant contribution from other isotopes.

• Need radiochemistry lab to process material in targets

– Handle up to 1 kC of activity

– Z separation of production products

• Need transport material from production area to lab to neutron facility

• Also may need to do chemistry on target after neutron irradiation

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Neutron Source Facility at RIA

1. Co-located but separate facility.2. Mono-energetic neutrons from ~10 keV to 20 MeV.3. High neutron fluxes, up to 1011 neutrons/sec on target.4. Radiochemistry facility for processing targets.

Different production mechanism are appropriate for different energies.– 3H(2H,n)4He: 14+ MeV– Deuteron Breakup: 7+ MeV– 2H(2H,n)3He: 2-9 MeV– 3H(p,n)3He or 7Li(p,n)7Be: 0.1-2 MeV– Moderated reactions: Below 100 keV

Strawman design completed and working with MSU and ANL to incorporate into RIA designs.

For more info: See L. Ahle, LLNL22

First Design of Neutron Source Facility

0.05-3 MeV Dynamitron 2-30 MeV

Linac

Radiochemistry Facilities

Experimental Halls

Approximate Foot Print 80 x 60 m

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Crucial cross sections have not been measured

There is a tremendous need for good measurements at RIAAND

NNSA needs nuclear physicists trained there!!and nuclear chemists

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Richard York presented a wonderful overview of RIA.I highly recommend his talk to anyone seeking to learn what RIA is and what it will do.

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• Combines advantages of projectile & target fragmentation techniques• Use all tools developed for rare isotope research

worldwide

The Rare Isotope Accelerator (RIA) Concept

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Comparison of Rare Isotope Intensities

• Enormous opportunities of advanced rare isotope accelerator facilities recognized worldwide• Significant inroads will be made by existing projectile

fragmentation and ISOL facilities • New ones planned or under construction.

• RIA will be needed to do the job right.• RIA will be the most powerful and versatile facility in the

world and exceed the capabilities of—ISAC by 1-2 orders of magnitude and more for non-ISOL beams

(only low-energy beams)—NSCL by up to two orders of magnitude for lighter nuclei and up to

four or five orders of magnitude for heavy nuclei (no reaccelerated beams)

—RIKEN by two orders of magnitude (no reaccelerated beams)—GSI (newly approved upgrade) by more than one order of

magnitude (no reaccelerated beams) 27

Summary

• RIA will be a world-leading isotope research facility.

• RIA provides a multitude of Isotope Recovery possibilities with great opportunities for cross-disciplinary research.

• RIA plus a neutron source facility can provide a productive research venue not available anywhere else in the world.

• Ready for CD-0 and start of CDR

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Robert Janssens reminded us of the broad scientific program enabled by RIA.

From proton-rich to stable nuclei to neutron-rich systems: We need a unified theory of nuclei

The increases in intensities of interesting isotopes are enormous.

Perhaps we can learn where the drip lines are.

Quarks to Cosmos (Q2C) In the overlap of physics and astronomy,what are the most compelling questions that need to be addressed?RIA: The origin of the elements above iron

r process; rp process; fundamental symmetries; understanding new astronomical observations etc etc.

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Sue Clark gave a disturbing report about the numbers of nuclear physicists, nuclear chemists and radio-chemists being trained. By almost every measure the outlook is bleak.

Universities are reducing faculty in these fields through retirements.

Other areas are being emphasized.

Will RIA and the RIA community world-wide be able to help?

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Larry Ahle concentrated on techniques to harvest radio-isotopes and create appropriate targets. He also presented a scheme to provide a neutron capability for RIA.

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Harvesting Isotopes at RIA

Harvesting Isotopes at RIAThree Locations for Isotope Harvesting

HI(RIB,xn) or (p/α,n) reactionIn inverse kinematics

IGISOL

ISOL

1. Production at first stripper – Direct Reactions

2. ISOL with Mass Separator

3. Fragmentation with IGISOL system32

Neutron Source Facility at RIA

1. Co-located but separate facility.2. Mono-energetic neutrons from ~10 keV to 20 MeV.3. High neutron fluxes, up to 1011 neutrons/sec on target.4. Radiochemistry facility for processing targets.

Different production mechanism are appropriate for different energies.– 3H(2H,n)4He: 14+ MeV– Deuteron Breakup: 7+ MeV– 2H(2H,n)3He: 2-9 MeV– 3H(p,n)3He or 7Li(p,n)7Be: 0.1-2 MeV– Moderated reactions: Below 100 keV

Strawman design completed and working with MSU and ANL to incorporate into RIA designs.

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First Design of Neutron Source Facility

0.05-3 MeV Dynamitron 2-30 MeV

Linac

Radiochemistry Facilities

Experimental Halls

Approximate Foot Print 80 x 60 m

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Ken Moody talked about the problems of doing the radio-chemical separations that are far from trivial. Some of the items of concern are:

Glove-boxes

Radiation exposures of operators

Subterranean rabbit systems

Widgets

Shielded hot cell operations

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Dave Vieira reviewed various ways to make radioactive targets. He also discussed the valuable experience currently being gained atLANSCE with DANCE and the Radioactive Sample Isotope Separator (RSIS). He discussed issues including purity and radioactivity.

He also presented a discussion of extremely interesting but really hard experiments test fundamental symmetries with magneto-optical traps (MOT’s).

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RIA and Medical Applications

• RIA will be a great place to make research quantities of tailor-made medical isotopes

• Thomas Ruth presented a compelling argument that the country should invest in R&D on systemic therapy– The goal: localize sources in tumor cells with radiation

penetrating only cellular dimensions– Tom also reviewed production approaches from neutrons

through ISOL.

• However, competition for beam time etc. makes RIA an unlikely source for material for therapy.

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Candidate radionuclides for radioimmunotherapy: 47Sc 64Cu 67Cu

90Y 105Rh 103Pd

111Ag 124I 142Pr

149Pm 153Sm 159Gd

166Ho 177Lu 186/188Re

194Ir 193m,195mPt 211At

RIA, DNCT, New Orleans ACS

TJ Ruth

27 March 2003

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Jose Alanso presented another approach to medical isotope production.

H-minus cyclotrons have revolutionized high current applications (Ga67, Tl201, Pd103)

He discussed the Rb82 to Sr82 generator.

He suggested using RIA to explore high currents of light ions as a potential technique to make medical isotopes: a technology “testbed”.

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Bob Rundberg presented a discussion of neutron capture cross section measurements being undertaken with DANCE at LANSCE – that will provide opportunities for rad-chem measurements before RIA

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ElectronicsShed

Target(20.26 m)

DANCE / Flight Path 14 at the Lujan Center

Collimator 4

DANCE Beam Stop

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The DANCE barium fluoride array

•162 segments with 4 different shape crystals(159 segments with crystals)

•High efficiency will allow measurementson milligram samples

• Highly segmented to allow detection ofradioactive targets

• Hit pattern analysis and reaction calorimetryto minimize backgrounds

• Inner radius = 17 cm• Crystal depth = 15 cm• Extensive Monte Carlo simulations to

design detector• All crystals will be delivered in FY2002• State-of-the-art fast digitizers for

data acquisition• Array will be completed in 2002, but some

data may be obtained with partial array.• M. Heil, et al., Nucl. Instr. Meth. A459,229-246 (2001)

Monte Carlo (GEANT) Simulations•M. Heil•R. Reifarth•F. KaeppelerForschungzentrum Karlsruhe

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Isotopes for Future Study define a multi-year program

Summary of 1997 Workshop at Livermore

Rad-Chem s-processIsotope Half-life Koehler-Kappeler G. Mathews Wilhelmy

Priority Feasible?

63 Ni 100 y 3 X79 Se 1.00E+04 y 1 X X X85 Kr 10.7 y 1 X X X86 Rb 18.8 d 188 Y 106.6 d R 489 Sr 50.5 d 290 Sr 28.8 y 2 X93 Zr 1.00E+06 y R X X95 Zr 64 d R 1 X94 Nb 2.00E+04 y 2 X95 Nb 3.50E+01 d 299 Tc 2.00E+05 y X X

106 Ru 367 d 2 X107 Pd 1.00E+06 y X X119 Sn Stable X X134 Cs 2 y 1 X135 Cs 3.00E+06 y 2 X X137 Cs 30.17 y 2 (X)141 Ce 32 d X X147 Nd 11 d 1147 Pm 2.6 y 1 X X151 Sm 90 y X X152 Eu 13 y R 1 X154 Eu 8.5 y R 1155 Eu 5 y R 1 X X153 Gd 241 d 1 X X X160 Tb 72.1 d 1161 Tb 6.9 d 2163 Ho 33 y 1 X (x-ray) X166 Ho 1200 y 2169 Er 9.4 d 1 X X170 Tm 128 d R 1 X (?) X X171 Tm 1.92 y R 1 X175 Yb 4.19 d 2 (X)176 Lu 3.60E+10 y X181 Hf 42.4 d 2182 Hf 9.00E+06 y 2 X179 Ta 1.70E+00 y 1 X185 W 75 d 1 X X186 Re 1.00E+05 y 1 X X191 Os 15.4 d 1 X192 Ir 74 d R 1 X193 Pt 50 y 1 X (x-ray) X X198 Au 2.69 d 2203 Hg 46.8 d 1204 Tl 3.77 y 1 X X205 Pb 1.00E+07 y X210m Bi 3.00E+06 y 2 X210g Bi 5.01 d 2 X

Isotope production at the ILL, 2002

Target Product Minimum Half LifeNd-146 Pm-147 3.8 mg 2.62 yrSm-154 Eu-155 8.9 mg 4.76 yrEr-170 Tm-171 9.4 mg 1.92 yr

FY 2002 FY 2003 FY 2004 FY 2005171Tm 238Pu 192Ir 232U

173,174,176Lu 170Tm 2 tbd 2 tbd155Eu 1 tbd

Stockpile Stewardship Target Plan

154Eu, 155Eu, 163Ho, 171 Tm, 176 Lu, 179 Ta186Re, 193Pt, 204Tl, 205Pb

s-Process Branch Point Nuclei(Half-lives greater than 1 yr)

151Sm, 147Pm (FY2002)63Ni, 85kr, 93 Zr, 99Tc, 134Cs, 152Eu

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Lee Bernstein discussed various approaches to rad-chem relevant cross sections both before RIA and with RIA. The most interesting technique is the “surrogate” approach with the STARSdetector.

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Surrogate neutron-induced reactions using charged particle beams

155Gdn

Neutron-induced reaction

157Gd

“Surrogate” reaction

3Heα

156Gd**

σn,x = Px σabsorption

From OpticalModel Calc.

“(n,γ)”

156Gd*

(3He, αγ)

Pγ

“(n,2n)”

154Gd*

(3He, α2nγ)

P2n

“(n,n’)”

155Gd*

(3He, αnγ)Pn

45LLNL Radioactive Ion Beam Project

Silicon Telescope Array for Reaction Studies

coupled to GAMMASPHERE

• 157Gd(3He,α /3He)156.157Gd at E(3He) = 45 MeV• 3 day run, Average Current = 0.2-0.3 pnAGAMMASPHERE STARS ∆E-E Particle ID

Chargedparticle

∆E E

First experiment completed: 4/0246LLNL Radioactive Ion Beam Project

Peggy McMahan presented a plan to conduct neutron cross section measurements on Zr.

The effort is a testimony to perseverance. (1) The financial support for the effort is the NNSA Stewardship Science Academic Alliance– BUT the $$$ have not yet arrived! (2) The experiment planned touse the 88-inch cyclotron – BUT the 88-inch has been closed!

These hurdles have not slowed the team!

The program is a model for RIA experiments: Make the Zr89, chemically separate it, neutron irradiate it, and count gammas off-line.

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Jeff Blackmon discussed the role that RIA and other RIB facilitiescan play in the study of nucleo-synthesis above iron. That question is of particular relevance to the Inter-Agency Working Group dealing with the “Quarks to Cosmos”report.

He argues convincingly for two independent ISOL platforms – the only problem may be the cost.

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Radioactive Targets for NuclearAstrophysics Experiments

J.C. Blackmon, Physics Division, ORNL

• Reactions involving radioactive nuclei are crucial for the synthesis of elements heavier than iron.

AGB stars

supernovae

• Measurements using radioactive targets are an efficient method for obtaining some of the nuclear data crucial for understanding the synthesis of the heavy elements.

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“Parasitic” production #2

Rare IsotopeAccelerator

RIA should have 2 independent ISOL platforms

#1 #2

RedundancyUnlikely that most ISOL targets could take full beam powerAllows one accelerated beam with one unaccelerated beam (traps or rats) Development could be done in parallel with experiments

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ConclusionsMeasurements with radioactive targets at are important for understanding the synthesis of heavy elements.

(n,γ) on s process branch points(n,α) for constraining the low energy αN interaction

Production of nuclei important for the s process at RIA is generally not competitive with reactor based production.

Exceptions: 133Xe, 135Cs, 163Ho

Production of targets of long-lived proton-rich nuclei at RIA is feasible and compelling.

Many interesting cases: 105Cd, 133Ba, 143Pm, 145Pm, …

RIA should have 2 independent ISOL platforms. Allows simultaneous:

accelerated beams for nuclear reaction measurementsun-accelerated beams (traps, rats, development)

RIA will tremendously improve our understanding of the r process.

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A significant opportunity to conduct radioactive ion beamresearch now is in nearby Canada at the ISAC facility that John D’Auria discussed.

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Production of Radioactive Beams

RIA

ISAC

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[TRINAT]

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Irshad Ahmad pointed out the important role for RIA in studying nuclear structure of trans-actinide nuclei. Of particular importance are experiments with neutron-rich beams.

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RIA Round Table Discussion

• Many of the programs discussed will require radiochemistry facilities at RIA. Yet, the number of radio-chemists is in steep decline with universities abandoning this field. What can and should we do – as a field– to reverse this trend?

• If you were to submit a proposal to RIA in the next month, what would it be?

• If you look into your crystal ball, what might the most excitingdiscovery be after RIA has operated for five years?

• What are the compelling arguments to spend a large fraction of the RIA instrumentation budget on radiochemistry?

ACS Session Radiochemistry at RIA57