RIA and the DOE/NNSA National Security Mission

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1 RIA and the DOE/NNSA National Security Mission Radiochemistry at RIA American Chemical Society, New Orleans Michael N. Kreisler National Nuclear Security Administration Lawrence Livermore National Laboratory University of Massachusetts Amherst March 27,

2 NNSA DP Science 2

3 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 way 3

Stockpile Stewardship Premise World-class

4 Stockpile Stewardship Premise World-class science, with detailed engineering investigations and highfidelity three-dimensional simulations, can maintain a reliable nuclear weapons stockpile Requirement Dynamic, vital and broad physical science community that engages the specific issues that matter in nuclear weapons Computing & Simulation High-Energy-Density Physics Materials, Physical Data, and Microsystems Hydrodynamics 4

5 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. 5

6 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. 6

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8 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 90 Zr Measure 89 Zr/ 90 Zr and 88 Zr/ 89 Zr Most of the intermediate cross sections are not measured RIA is NEEDED! 9

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11 5 Sensitivity Study for Simple Reaction Network The Reaction Network 88 Zr 89 Zr 90 Zr Reaction For 10% change in cross section 89 Zr/ Z L Zr/ 89 Zr Change in Isotope Ratio For 50% change in cross section 89 Zr/ Zr L Zr/ 89 Zr 90 Zr(n,2n) 89g Zr 7.2% 4.0% 36% 20% 90 Zr(n,2n) 89m3 Zr 1.3% 2.0% 6.5% 10% 89 Zr(n,2n) 88 Zr 2.3% 8.4% 11.5% 42% 89 Zr(n,γ) 90m4 Zr 4.2% 1.1% 21% 5.5% 89 Zr(n,γ) 90 Zr 3.2% 0.9% 16% 4.5% 88 Zr(n,γ) 89m3 Zr 0.2% 3.1% 1% 15.5% 89m3 Zr(n,2n) 88 Zr 0.1% 1.6% 0.5% 8% 90m4 Zr(n,2n) 89 Zr 1.0% 0.5% 5% 2.5% Green: Cross section for sum (g.s m) known to 2% for E n = MeV. Red: Cross section determined by calculation only. It is important to measure these cross sections accurately from threshold to 20 MeV. 12

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18 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 19

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20 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 be significant 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 21

21 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 neutrons/sec on target. 4. Radiochemistry facility for processing targets. Different production mechanism are appropriate for different energies. 3 H( 2 H,n) 4 He: 14+ MeV Deuteron Breakup: 7+ MeV 2 H( 2 H,n) 3 He: 2-9 MeV 3 H(p,n) 3 He or 7 Li(p,n) 7 Be: 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, LLNL 22

22 First Design of Neutron Source Facility Experimental Halls MeV Dynamitron 2-30 MeV Linac Approximate Foot Print 80 x 60 m Radiochemistry Facilities 23

23 Crucial cross sections have not been measured There is a tremendous need for good measurements at RIA AND and nuclear chemists NNSA needs nuclear physicists ^trained there!! 24

24 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. 25

25 The Rare Isotope Accelerator (RIA) Concept Combines advantages of projectile & target fragmentation techniques Use all tools developed for rare isotope research worldwide 26

26 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

27 Summary RIA will be a world-leading isotope research facility. RIA provides a multitude of Isotope Recovery possibilities with great opportunities for crossdisciplinary 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 28

28 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. 29

29 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? 30

30 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. 31

31 Harvesting Isotopes at RIA Three Locations for Harvesting Isotopes Harvesting at RIA ISOL HI(RIB,xn) or (p/α,n) reaction In inverse kinematics IGISOL 1. Production at first stripper Direct Reactions 2. ISOL with Mass Separator 3. Fragmentation with IGISOL system 32

32 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 neutrons/sec on target. 4. Radiochemistry facility for processing targets. Different production mechanism are appropriate for different energies. 3 H( 2 H,n) 4 He: 14+ MeV Deuteron Breakup: 7+ MeV 2 H( 2 H,n) 3 He: 2-9 MeV 3 H(p,n) 3 He or 7 Li(p,n) 7 Be: MeV Moderated reactions: Below 100 kev Strawman design completed and working with MSU and ANL to incorporate into RIA designs. 33

First Design of Neutron Source Facility Experimental Halls 0.

33 First Design of Neutron Source Facility Experimental Halls MeV Dynamitron 2-30 MeV Linac Approximate Foot Print 80 x 60 m Radiochemistry Facilities 34

34 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 35

35 Dave Vieira reviewed various ways to make radioactive targets. He also discussed the valuable experience currently being gained at LANSCE 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). 36

36 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. 37

37 Candidate radionuclides for radioimmunotherapy: 47 Sc 64 Cu 67 Cu 90 Y 105 Rh 103 Pd 111 Ag 124 I 142 Pr 149 Pm 153 Sm 159 Gd 166 Ho 177 Lu 186/188 Re 194 Ir 193m,195m Pt 211 At 27 March 2003 RIA, DNCT, New Orleans ACS TJ Ruth 38

38 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 test bed. 39

39 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 40

40 DANCE / Flight Path 14 at the Lujan Center Target (20.26 m) Electronics Shed Collimator 4 DANCE Beam Stop 41

41 The DANCE barium fluoride array Monte Carlo (GEANT) Simulations M. Heil R. Reifarth F. Kaeppeler Forschungzentrum Karlsruhe 162 segments with 4 different shape crystals (159 segments with crystals) High efficiency will allow measurements on milligram samples Highly segmented to allow detection of radioactive targets Hit pattern analysis and reaction calorimetry to 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, (2001) 42

42 Isotopes for Future Study define a multi-year program Summary of 1997 Workshop at Livermore Rad-Chem s-process Isotope Half-life Koehler-Kappeler G. Mathews Wilhelmy Priority Feasible? 63 Ni 100 y 3 X 79 Se 1.00E+04 y 1 X X X 85 Kr 10.7 y 1 X X X 86 Rb 18.8 d 1 88 Y d R 4 89 Sr 50.5 d 2 90 Sr 28.8 y 2 X 93 Zr 1.00E+06 y R X X 95 Zr 64 d R 1 X 94 Nb 2.00E+04 y 2 X 95 Nb 3.50E+01 d 2 99 Tc 2.00E+05 y X X 106 Ru 367 d 2 X 107 Pd 1.00E+06 y X X 119 Sn Stable X X 134 Cs 2 y 1 X 135 Cs 3.00E+06 y 2 X X 137 Cs y 2 (X) 141 Ce 32 d X X 147 Nd 11 d Pm 2.6 y 1 X X 151 Sm 90 y X X 152 Eu 13 y R 1 X 154 Eu 8.5 y R Eu 5 y R 1 X X 153 Gd 241 d 1 X X X 160 Tb 72.1 d Tb 6.9 d Ho 33 y 1 X (x-ray) X 166 Ho 1200 y Er 9.4 d 1 X X 170 Tm 128 d R 1 X (?) X X 171 Tm 1.92 y R 1 X 175 Yb 4.19 d 2 (X) 176 Lu 3.60E+10 y X 181 Hf 42.4 d Hf 9.00E+06 y 2 X 179 Ta 1.70E+00 y 1 X 185 W 75 d 1 X X 186 Re 1.00E+05 y 1 X X 191 Os 15.4 d 1 X 192 Ir 74 d R 1 X 193 Pt 50 y 1 X (x-ray) X X 198 Au 2.69 d Hg 46.8 d Tl 3.77 y 1 X X 205 Pb 1.00E+07 y X 210m Bi 3.00E+06 y 2 X 210g Bi 5.01 d 2 X Isotope production at the ILL, 2002 Target Product Minimum Half Life Nd-146 Pm mg 2.62 yr Sm-154 Eu mg 4.76 yr Er-170 Tm mg 1.92 yr Stockpile Stewardship Target Plan FY 2002 FY 2003 FY 2004 FY Tm 238 Pu 192 Ir 232 U 173,174,176 Lu 155 Eu 1 tbd 170 Tm 2 tbd 2 tbd s-process Branch Point Nuclei (Half-lives greater than 1 yr) 151 Sm, 147 Pm (FY2002) 63 Ni, 85 kr, 93 Zr, 99 Tc, 134 Cs, 152 Eu 154 Eu, 155 Eu, 163 Ho, 171 Tm, 176 Lu, 179 Ta 186 Re, 193 Pt, 204 Tl, 205 Pb 43

43 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 STARS detector. 44

44 Surrogate neutron-induced reactions using charged particle beams n Gd Gd α 3 He Neutron-induced reaction 156 Gd** Surrogate reaction P γ P 2n σ n,x = P x σ absorption ( 3 He, αγ) 156 Gd* P n ( 3 He, αnγ) ( 3 He, α2nγ) 154 Gd* (n,γ) LLNL Radioactive Ion Beam Project 155 Gd* (n,n ) (n,2n) From Optical Model Calc. 45

Silicon Telescope Array for Reaction Studies

156.157 Gd at E( 3 He) = 45 MeV 3 day run,

3 pna GAMMASPHERE STARS E-E Particle ID Charged

45 Silicon Telescope Array for Reaction Studies coupled to GAMMASPHERE 157 Gd( 3 He,α / 3 He) Gd at E( 3 He) = 45 MeV 3 day run, Average Current = pna GAMMASPHERE STARS E-E Particle ID Charged particle E E First experiment completed: 4/02 LLNL Radioactive Ion Beam Project 46

46 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 to use 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 offline. 47

47 Jeff Blackmon discussed the role that RIA and other RIB facilities can 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. 48

Radioactive Targets for Nuclear Astrophysics Experiments J.C.

radioactive nuclei are crucial for the synthesis of elements

AGB stars supernovae Measurements using radioactive targets are

48 Radioactive Targets for Nuclear Astrophysics 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. 49

Parasitic production #2 Rare Isotope Accelerator #1 #2 RIA should have 2 independent ISOL platforms Redundancy Unlikely that most ISOL targets could

49 Parasitic production #2 Rare Isotope Accelerator #1 #2 RIA should have 2 independent ISOL platforms Redundancy Unlikely that most ISOL targets could take full beam power Allows one accelerated beam with one unaccelerated beam (traps or rats) Development could be done in parallel with experiments 50

50 Conclusions Measurements 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 measurements un-accelerated beams (traps, rats, development) RIA will tremendously improve our understanding of the r process. 51

51 A significant opportunity to conduct radioactive ion beam research now is in nearby Canada at the ISAC facility that John D Auria discussed. 52

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53 Production of Radioactive Beams RIA ISAC 54

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55 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. 56

56 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 exciting discovery 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 RIA 57

NATIONAL NUCLEAR SECURITY AND OTHER APPLICATIONS OF RARE ISOTOPES Michael N. Kreisler National Nuclear Security Administration Lawrence Livermore

NATIONAL NUCLEAR SECURITY AND OTHER APPLICATIONS OF RARE ISOTOPES Michael N. Kreisler National Nuclear Security Administration Lawrence Livermore National Laboratory University of Massachusetts Amherst