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A ssay and A cquisition of R adiopure M aterials

DUSEL Experiment Development and Coordination (DEDC) Internal Design Review July 16-18, 2008 Steve Elliott, Derek Elsworth, Daniela Leitner, Larry Murdoch, Tullis C. Onstott and Hank Sobel. A ssay and A cquisition of R adiopure M aterials. Craig Aalseth Donald Abraham

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A ssay and A cquisition of R adiopure M aterials

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  1. DUSEL Experiment Development and Coordination (DEDC)Internal Design ReviewJuly 16-18, 2008Steve Elliott, Derek Elsworth, Daniela Leitner, Larry Murdoch, Tullis C. Onstott and Hank Sobel

  2. Assay and Acquisition of Radiopure Materials Craig Aalseth Donald Abraham Gary A. Anderson Henning Back Tim Classen Jodi Cooley-Sekula Priscilla Cushman * Jason Detwiler Yuri Efremenko Brian Fujikawa Reyco Henning Eric Hoppe Tina Keller Robert McTaggart Dongming Mei Andreas Piepke Mark L. Pitt Richard Schnee Tom Schumacher John Wilkerson * Working Group Leader

  3. Science A Dedicated Facility for the Assay, Control, and Production of Low Radioactivity Materials has been recognized as an essential shared task from the beginning of the DUSEL process. Cost Efficient Sharing of Screening Detectors Cu electroforming Expert Personnel Materials Databases Simulation Software Characterization tools Promote and foster Cross-cutting applications New Assay Techniques Training and Education

  4. Science Necessary Component to Neutrinoless Double Beta Decay Dark Matter Searches Solar Neutrino Creates new research opportunities in Radiation Biology Microbiology and Extremophiles Circuit manufacture Geology and hydrology Archaeology Homeland Security

  5. Gamma Screening Surface or 300’ level (~1 mBq/kg) a) Commercial HPGe b) pre-screeners c) NAA screeners d) E&O, archaeology, local users… 4850’ facility ( ~0.1 mBq/kg) a) Bank of sensitive, shielded HPGe (both planar and well) b) For dark matter, double beta decay, solar neutrinos c)Sensitive (TBD) applications in microbio, geology, security Ultralow Facility (0.1 - 10 μBq/kg) a) Coincident HPGe at 4850’ b) Next generation large liquid scintillation counting at 7000’

  6. Gamma Screening Standard HPGe 4850-ft level (EIE) Coincident Counting

  7. Neutron Activation Analysis • Transmute stable isotope (impurity) into a short lived radioactive isotope through neutron capture • Neutron activation via a nuclear reactor (in general) • Search for activated isotope decay by identifying signature gamma through gamma ray spectroscopy Example: 232Th + n  233Th(t1/2=22m)  e- + 233Pa(t1/2=27d)  e- + 233U(t1/2=1.6E5y) + γ

  8. Neutron Activation Analysis Sample preparation • Any uranium, thorium, or potassium in or on the sample will activate and be counted • Creating clean samples requires clean chemistry facilities with hoods for working with acids (wet lab). Radiochemical Neutron Activation Analysis • It is possible to further increase the sensitivity of NAA by isolating the target isotope after irradiation. • Requires radiochemistry: dedicated wet chemistry area with hood for handling solvents and acids needed for ion exchange chemistry Dedicated HPGe at 300’ or surface

  9. Neutron Activation Analysis • Sensitivities are largely driven by counting times.

  10. Beta Screening Commercial standard is liquid scintillation counters with backgrounds ~ few per hour (1 at surface or 300’ level) Better beta screening needed by • Dark matter experiments: CDMS & Edelweiss limited by beta contamination (mostly 210Pb from radon) on surface or in thin films of detectors • Radioisotope dating with beta sources competitive with AMS 14C/12C to 10-18, 3H/H to 10-20 also 10Be, 210Pb, 36Cl • Low-level tracers for uptake and transport in biological studies • 3 Large gas chambers shielded at 4850’ should screen to ~1 / m day • Drift chamber (DUSEL R&D funded project “BetaCage”) • Cloud chamber • Ideal for alpha screening, too

  11. Beta Screening Modest Infrastructure 1. Bkgd dominated by external g,  clean copper, lead, or large water shield 2. Rn-free sample loading 3. Gas handling

  12. Alpha Counting Current alpha counting sensitivity limited to ~ 0.1 a/cm2-day large area wire chambers (~1000 cm2) or small (~10 cm2) Si detectors. Not competitive with gamma for bulk U and Th activity, confined to niche areas-- investigation of surface contamination and isotopes with no associated gamma activity, especially 210Po (a radon daughter). Improvement by x100 in sensitivity seems achievable. Goal: 1000 cm2 device with 1 count per day background. Commercially available 1800 cm2 ion chamber (XIA) is promising. limited by internal contamination, should be possible to fix. Reaching 0.001 a/cm2-day would allow exploration of surface contamination CDMS, currently ~0.003/ cm2-day COUPP, ~0.8/ cm2-day Others…? Main requirements for counting facility are Class 100 clean room space Sample cleaning equipment: ultrasound, high purity water Radon at level of normal surface air (~10 Bq/m3)

  13. Radon Mitigation Requirements for DUSEL Needs to be determined, depends on Volume of space that needs radon reduced air or radon free gas Amount of make-up air in cleanroom Level of radon exisiting in cavern Cavern-wide radon mitigation (ventilation) Problems with Radon Radon is a daughter in both the 238U and 232Th decay chains Can cause backgrounds direct gamma counting determination of U and Th Daughters of radon decay can plate-out onto sensitive detector surfaces Removing Radon Use radon free gases such as boil off LN to obtain lowest possible level in detector volumes When air is required: adsorb radon onto activated charcoal Examples include: Borexino cleanroom at Princeton Super Kamiokande NEMO3 radon free tent HPGe spectrum with gamma lines from the 238U decay chain. Probably due to 222Rn in the sample chamber

  14. Radon emanation • Radon emanates from materials due to radium contamination • Detection: Sample material is sealed in an “emanation chamber” where radon builds up over time. Measured using standard radon detection methods: Example of systems: • SNOlab has 8 electrostatic counters (I. Lawson, DUSEL Town Meeting, 2007) Sensitivity = 5 - 10 atoms (222Rn) per day • MPIK in Heidelberg uses proportional counters (Astropart. Physics 18 (2002) 1)Sensitivity = 1-5 atoms (222Rn) per day • DUSEL requirements • Need to determine what is required by experiments. • Compare materials, sensitivities, vs HPGe • A single SNOlab chamber turn-around is one month

  15. Mass Spec and other Techniques • Need to evaluate what assay tools must be located underground and which can be sent off-site • Dedicated, extensive underground analytical lab likely needed due to low-background and purity requirements • Best sensitivities can be submicro Bq/kg • Based on a wide spectrum of analytes and anticipated sensitivity the current underground candidates likely are: • Inductively Coupled Plasma/Optical Emission Spectroscopy (ICP/OES) • Inductively Coupled Plasma/Mass Spectroscopy (ICP/MS) • Laser Ablation-ICP/MS • Secondary Ion Mass Spectrometry (SIMS) • Glow Discharge or Thermal Ionization Mass Spectroscopy (GD/MS or TIMS) • Also need chemistry/wet lab facilities to support the sample preparation/dissolution

  16. Mass Spec and other Techniques • Other Analytical tools likely to be needed underground • Optical Microscopy • Scanning Electron Microscopy (SEM) with various electron excitation spectroscopies and electron backscatter • Transmission Electron Microscopy (TEM) • Scanning Tunneling Microscopy/Atomic Force Microscopy (STM or AFM) • Physical Properties Testing • Hardness and tensile strength • Grain size and orientation evaluation (from SEM and EBSD)

  17. Cryogens Most of Experiments will require Cryogens and Purified Gases • Detectors, Coolants and/or Shielding for Dark Matter and Double Beta decay • Coolants for Gamma Counting • Radon Reduced gas for Clean rooms and Glove Boxes Organizing their production (what we need to determine) Example of Pure Nitrogen Generator installed at Kamioka: Productivity: 40Nm3/hr of N2 Levels of purity:39Ar < 0.2 μBg/m385Kr << 1 μBg/m3 Rn < 3 μBg/m3 • Footprint underground • Supply of Gases and Electrical Power • System of delivery to Experiments • Staff for Operation and Maintenance

  18. Electroforming Facility • Ultra High Purity Copper is needed for a wide variety of experiments including those for the next generation of neutrino physics, dark matter, and material sciences • Submicro Bq/kg is now possible • Must be electroformed underground to minimize cosmogenic in-growth of impurities and retain original crystal integrity • Other materials may also require electroforming. The number of experiments needing the material and the material compatibility must be evaluated to determine appropriate facility requirements

  19. Material Storage and Cleanliness Detector/Shielding Storage (reduce cosmogenic activation)At least 300’ and Rn-free environment Pure Cu, Lead Shielding Common small parts (evaluate this possibility) Purified Water Common purification plant (design facility) Common screening location (water shield) Clean Machine Shop Determine Needs and Quality Assurance procedure Determine boundaries between this S4, DM Infrastructure S4, and Facilities

  20. Electroforming Facility • Highest purity copper in the world to be produced • Facilities will be extensive consisting of the main electroforming area, the cleaning/treatment area, and the storage area • Cleanroom class 1000 for electroforming, class 100 for cleaning area • Large quantities of acid sulfate electrolyte anticipated • Extensively instrumented for process monitoring Draw from recent design experience of similar Pacific Northwest National Lab space

  21. Education and Outreach Undergraduates Contributions to Site Characterization, summer jobs Graduate Students/Post-Docs Training Opportunities In-service/Pre-service K-12 Teachers Physics of Atomic Nuclei - Underground (SD Pilot Workshop – Summer 2008) Development of Curriculum Materials based on SD State Standards Annual visit to South Dakota: Math and Science teachers in January/February K-12 Students Physics of Atomic Nuclei - Underground (include students - Summer 2009) Native American serving high schools, tribal colleges   Outreach Sanford Center – Contribute exhibits to facility 300 ft level – access to public, tours Summer support for K-12 in-service/pre-service teachers to act as docents Connection to Science on the Move program in SD standard counting equipment (i.e., radiation monitors, cosmic ray detectors) curriculum development

  22. Integrative Functions • Enabling the Physics ExperimentsFull characterization of Homestake Rock/water radio-isotopes, radon, neutron/muon flux Scheduling tools Onsite Assay (managing common facility) Offsite samples (ICPMS, NAA Irradiation, Underground sites…) Materials Database Simulation Software Links to ILIAS JRA1, sharing expertise and info • Creating the Larger User Community (Integrative website)Cross-disciplinary Workshops some in common with “Cross-cutting group” Training Programs and Seminars Collaborations and Proposals with Industry, ILIAS, Universities, Nat’l Labs

  23. Schedule: Year 1 Design “Facility for AARM” (FAARM) Determine needs of ISE Identify limited R&D required Participate and plan SUSEL screening programEPSCoR, MRI, Donations from existing sites Start Training program between SD and Kimballton/Soudan Characterize the DUSEL environment Compile all exisiting and historical data Cavern U/Th/K (chemical and g spectroscopy), Rn survey Cross-calibrate with ILIAS (Jan Kiesel - standard survey) Create AARM integrative group with website Integrate with other S4 groups (DUSEL integration workshop) Identify new user base (Synergies workshop -shared with cross- cutting S4 and E&O)

  24. Schedule: Year 2 Design FAARM Design, schedule and implementation plan for FAARM DUSEL AARM Workshop R&D on target opportunities Training (Schedule courses at SUSEL, invite participants) Start SUSEL screening (part of staged DUSEL design) Characterize the DUSEL environment Finish initial surveys Design/Implement longterm muon/high energy neutron monitoring Design and cost overall Radon mitigation plan Expand website functionality Create user interface for screening (incl. existing sites, ILIAS) Create Materials Database and Software repository Consolidate new user base (2nd Synergies workshop)

  25. Schedule: Year 3 Complete FAARM design Finish design of DUSEL facility (DUSEL integration workshop) Screening & Cu Electroforming proceeding at SUSEL Training Seminars at SUSEL Maintain and Expand Integrative Website Screening schedules integrated between SUSEL and other sitesInclude design plans from new user base (3nd Synergies workshop)

  26. Budget: Year 1 Design “Facility for AARM” (FAARM) Project engineer (15 weeks) $100k Video conferencing, supplies, etc $2k Secretarial support $10k Characterize the DUSEL environment Travel to site (10 trips of 1 week each) $15k 1 mo. Summer salary (SD person?) $9k Summer travel for others $10k 2 undergrads, 2 grads to help (E&0, collaborate with EPSCoR) $20k Host Jan Keisel & staff (ILIAS) $30k Create AARM integrative group with website Software engineering support $50k DUSEL integration workshop $20k Synergies workshop $25k

  27. Budget: Year 2 Design FAARMProject engineer (15 weeks) $100k DUSEL AARM Workshop $20k R&D (not yet specified) $40k Characterize the DUSEL environment Engineering (Rn survey, mitigation) $30k Muon and HE neutron system $30k 1 mo. Summer salary (SD person?) $9k Summer travel for others $10k 2 undergrads, 2 grads to help (E&0, collaborate with EPSCoR) $20k Expand website functionality Software support $40k 2nd Synergies workshop $25k

  28. Budget: Year 3 Complete FAARM design Project engineer (15 weeks) $100k DUSEL integration workshop $20k 1 mo. Summer salary (SD person?) $9k Summer travel for others $10k 2 undergrads, 2 grads to help (E&0, collaborate with EPSCoR) $20k Maintain and Use Integrative Website Software support $30k 3nd Synergies workshop $25k

  29. ISE Estimated Budget Materials Assay Materials Storage Materials Processing

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