Assay and Acquisition of Radiopure Materials Priscilla Cushman University of Minnesota July 14, 2010 NSF Review PRESENTATION(s) OUTLINE P. Cushman S4 Management S4 Progress Report DUSEL Facility Design Schedule and Cost D-M. Mei Homestake Backgrounds Simulation Data: , n, radon Gamma Screening L. Petersen Detailed FAARM design Power & Cooling DUSEL Issues Schedule and Cost

Priscilla CushmanNSF S4 Review University of MinnesotaJuly 14, 2010 Assay and Acquisition of Radiopure Materials Structure and Management of the AARM S4

Principle Investigators Priscilla Cushman (University of Minnesota) Dongming Mei (University of South Dakota) Kara Keeter (Black Hills State University) Richard Schnee (Syracuse University) Assay and Acquisition of Radiopure Materials Characterize radon, neutron, gamma, and alpha/beta backgrounds at Homestake Develop a conceptual design for a common, dedicated facility for low background counting and other assay techniques. Assist where appropriate in the creation of common infrastructure required to perform low background experiments. Perform targeted R&D for ultra-sensitive screening and water shielding Engineering Consortium CNA Consulting Engineers (Lee Petersen) Dunham Associates Miller Dunwiddie Architecture, Inc

Broader Collaboration provides input Scientific Collaboration Craig Aalseth Henning Back Tim Classen Jodi Cooley Darrin Grant Yuri Efremenko Brian Fujikawa Reyco Henning Jeff Martoff Robert McTaggart Eric Hoppe Andreas Piepke Andrew Sonnenshein John Wilkerson Tullis Onstott International Scientific Advisory Panel Laura Baudis (Zurich University) Richard Ford (Queen’s University, SNOLab) Gilles Gerbier (CEA Saclay) Gerd Heusser (Max Planck Institute, Heidelberg) Andrea Giuliani (University of Insubria (Como), Coordinator of ILIAS Continuation) Mikael Hult (European Commission: JRC Inst. for Reference materials and Measurements) Vitaly Kudryavtsev (University of Sheffield) Pia Loaiza (Laboratoire Souterrain de Modane) Matthias Laubenstein (INFN, Gran Sasso Laboratory) Neil Spooner (University of Sheffield)

Working Groups are our basic unit Priscilla CushmanNSF S4 Review University of MinnesotaJuly 14, 2010

Planning for Progress Wiki Organizational Page Agendas for weekly meetings, links to docushare, spreadsheets, schedules, drawings, etc. Working Group Meetings As needed, often and small phone conferences Weekly Teleconferences Integration Working Group meeting. PI’s and DUSEL reps Collaboration Meetings Twice a year with the broader collaboration. March 20, 2010 at Berkeley and Late October 2010 at Homestake Contact People P. Cushman (scientific, management)D-M. Mei (Homestake characterization, Sanford) L. Petersen (engineering integration)K. Keeter (EH&S Liason) C. Keller (E&O)R. Altes (Liason Engineer) Y-D. Chan (Liason Scientist)

Assay and Acquisition of Radiopure Materials Status and Progress Report on Milestones Priscilla CushmanNSF S4 Review University of MinnesotaJuly 14, 2010

Early timetable for DUSEL Conceptual Design Focus on MREFC integration Met all our “deliverables” to DUSEL Module occupancy in 2017  Screening starts in 2019 Organize earlier screening for other ISE Concentrate FAARM on the ultra-sensitive application Integrated resource-loaded schedule: S4  early screening  MREFC funding  construction, installation and commissioning Realignment of Tasks and Schedule

Schedule for AARM S4 study Site Characterization and Simulation Studies Homestake delays redo MC with new design move to 2 nd yrconcentrate effort meet goal possible delay happening now Determine maximum acceptable

Schedule for AARM S4 study Site Characterization and Simulation Studies First pass done Bio/Geo requires work already done

Milestones for the AARM Cooperative Agreement Translating this into a Conceptual Design

Assay and Acquisition of Radiopure Materials FAARM = Facility for Assay and acquisition of Radiopure Materials Priscilla CushmanNSF S4 Review University of MinnesotaJuly 14, 2010

Design and Location of FAARM Design Principles Surface/Shallow Easy access for less sensitive screening E&O projects, NAA HPGe, radiochemistry lab New labs as needed (not in our “plan” – we will send samples out) ICPMS, surface characterization, atom trace analysis Depends on the infrastructure in the surface campus 4850-ft level FAARM deep enough for ultra sensitive screening and dark matter prototype testing close to experiments for easy access (drive in large items) share water purification and cryogen infrastructure unite functions under a dedicated staff Need new approach to multi-user shielding: individual lead shields too expensive and not radiopure neutron shielding required for DM prototypes and Immersion tank muon capture, activation, a-n/fission become important

Elements of FAARM Entire facility is class 10,000 clean room, < 20 Bq/m 3 Several class 1000 clean rooms Ateko (NEMO facility provided 0.01 Bq/m 3 breathable air at 150 m 3 /h) Radon-mitigated zones (<1 Bq/m 3 ) and assembly areas (<0.1 Bq/m 3 ) Radon-free storage and unified LN system Wet benches, clean machining, hoods, etc Instrumented Water Shield with toroidal interior acrylic room Houses ultra-sensitive screeners (GeMPI style, BetaCages) Reduce cost of individual lead shielding ($2M savings) Active Muon veto, Neutron & Gamma shielding Outer shield of Immersion Tank, Space for Experiments & R&D Prototypes Top-loading Immersion Tank Modeled on the Borexino CTF Whole body counting with 0.1 counts/day, E > 250 keV U/Th at.01/.04 ppt, surface  at < 1 count/m 2 /day (unsealed) 6 x cts/kg/keV/day from Compton continuum OPTION: Could be replaced by highly segmented germanium

Elements of FAARM Served by a trained technical staff Develop staff in the Early Screening Program (DULBCF) Scheduling tools to optimize efficient use of screeners Integrate with worldwide screening In-house analysis tools and database Transition the screening in a phased manner Less sensitive screeners benefit from common facility outside shield but inside clean area Radon emanation, XIA alpha screeners, conventional HPGe Areas for bio/geo/physics assembly Intellectual center for a new field of low background studies

4 tonnes of scintillator (PC g/L PPO) 1m radius 500μm Nylon vessel for scintillator 2 m radius “shroud” vessel to shield Rn 3.6 p.e./PMT for 1 MeV electron Muon veto PMTs on floor 100 PMTs (Optical coverage: 21%) Buffer of water – 2.3m vessel to PMT Energy saturation: 6 MeV Borexino Counting Test Facility

CTF-like Immersion Tank for Screening Instrumented water shield becomes outer shroud and veto Low radioactivity QUPIDs can be placed closer to LS Bigger 2m diameter nylon bag filled with LS (LAB proposed) Purification methods ( g/g U/Th andd g/g K) Distillation (also removes Rn) Water extraction N 2 stripping Solid-column adsorption Sensitive to bulk gammas betas and alphas from surface betas inside 50  m nylon sample bag Moderate energy resolution & Efficiency Distinguish  via event reconstruction  via pulse shape 50%

Elements of FAARM

Water Shield Simulations Optimize shield thickness Incorporate detailed FAARM design into Geant4 this Fall Rock (Homestake 4850’) 238 U 0.55 ppm 232 Th 0.3 ppm 40 K 2.21% Attenuation through Water + Stainless Steel X radiogenic neutrons cosmogenic neutrons (tagged) Cavern radioactivity after 2.3 m thick wall  7.974×10 -5 /cm 2 /s n 4.817× /cm 2 /s ContamStainless SteelAcrylic 238 U0.1 ppb 9.5x ppt 232 Th0.1 ppb 2.3x ppt 40 K0.028 ppb 1.2x x10 -4 ppb 60 Co4.6x ppb 6.4x10 -5 Total: 7.7x10 -5 Total: ~10 -5 vs gamma’s from rock

Simulation Plans for S Immersion Tank Geant MC (BHSU, UM) Light collection, signal discrimination, QUPID placement Complete FAARM Simulation Merge Shield (USD) & Tank MC Include Syracuse studies on screener shielding Independent work on Cosmogenic neutrons CDMS (Soudan) and LUX (Homestake) simulations continue to improve Homestake – neutron detectors for 800 level Soudan – DUSEL R&D neutron multiplicity meter (USB & Case) plus cavern-wide granular muon detector Multi-depth MC with shower generation Benchmark to neutron data Longterm Neutron data-taking in multiple sites

Assay and Acquisition of Radiopure Materials Schedule and Cost of FAARM Priscilla CushmanNSF S4 Review University of MinnesotaJuly 14, 2010

S4: (9/09 – 9/12) Design of FAARM and the Studies associated with it. Post-S4: (9/12  MREFC funding start) Additional DUSEL-specific design work for MREFC DULBCF: (9/09  FAARM civil construction complete) Early screening program, staff development, EPSCOR elements, R&D, complete characterization of Homestake FAARM (1/14  1/17) Final engineering-level design, procurement, immersion tank element fab, photodetector screening & QA FAARM ( 1/17  12/17) Civil Construction (12/17  6/19) Installation, commissioning, screening starts on 8/18 Getting to the FAARM Each stage has a different source of funding

DUSEL Early Screening Program Rationale Homestake does NOT have enough room and delays are preventing early access Utilize existing underground sites, but integrate under the DUSEL umbrella Begin to build a coherent team and staff Surface site at USD becomes main campus (equidistant to both deep sites) Hire a director (+students, etc) Keenan Thomas (USD masters student) Build scheduling tool for multiple sites Tightest coordination between LBNL + CUBED (USD + Sanford) + Soudan Davis Cavern + Soudan can provide enough new deep real estate until 2019 FAARM Need to develop & operate GeMPI and segmented HPGe, Beta cages Cosmogenic simulations benchmarked to neutron data from multiple levels Such a program can ramp up screening and move seamlessly to FAARM when ready Combination of EPSCOR, Sanford, new initiatives – before MREFC funding

Construct conventional screeners, install at Sanford Purchase 1 st GeMPI, prepare other gamma screeners for Davis Install neutron detector at 800’ Homestake Build additional neutron detectors Build electroformed copper cryostat for GeMPI at Soudan (Reeves &Sons) Hire Keenan, Begin integration of sites Screening begins at Sanford and LBNL is integrated Install 1 st GeMPI in new cryostat at Soudan and study backgrounds Install bank of neutron detectors at Soudan and lower Homestake levels Purchase 2 nd GeMPI and Clover detector (3 rd GeMPI if funds) Install Clover at Sanford and 2 nd GeMPI at Soudan (in coincidence mode) New beta screeners will be ready by this time (Soudan or Davis) Ultra-sensitive screening at Soudan & Davis. Dedicated screeners in Kimballton and WIPP are integrated Continue to add functionality (up to 4 GeMPI, 3 BetaCages, XIA alpha) DUSEL Early Screening Program Schedule

Schedule for FAARM Procurement and Assembly Definition: Assembly is building of FAARM by contracted labor Installation of scientific equipment by Institutional staff Before Module is ready, but money is allocated Detailed engineering-level design Obtain bids, contracts and permits and hire contractor Assemble and test water purification system Procure radon system from Ateko (year lead time) Choose photodetectors, screening and testing, bids Purchase photodetectors, calibration and QA, electronics Procure nylon and build dedicated clean room Build nylon vessel in clean room Once module is ready (Jan 2017) and radon < 100 Bq/m 3 (ventilation, rock coating) Install Ateko in module, operate temporary radon-free room for sensitive materials Water tank assembly incl torus + civil + radon under direction of contractor Ateko moved to final location inside FAARM Beneficial occupancy one year later.

Schedule for FAARM Installation and Commissioning After Beneficial Occupancy Establish moderate cleanliness protocols immediately after heavy construction Clean entire lab as soon as possible Clean and coat interior of shield, Install cables, plumbing, air, cryogen system Initial water fill and test plumbing – drain and clean Install Water Shield PMTs – fill shield, operate and calibrate PMTs Comission DAQ and shield – long muon run - drain Establish tight cleanliness protocol, including showers and radon mitigation Measure particulate level and radon to confirm – commission monitoring At least one sensitive HPGe moved to FAARM as bkgd monitor Install nylon vessel and QUPIDs (test and calibrate) Fill Immersion Tank with LS Install nitrogen blanket, clean room – Purity studies with QUIPIDs Fill shield – Combined Water + LS test and bkgd run Move other screeners in parallel with Immersion Tank commissioning

All screeners already bought, tested, and in operation from DULBCF era Screening must continue with as few interruptions as possible Staff is already in charge of all screeners, regardless of location Each sensitive screener is commissioned at FAARM before the next one dismantled Decommissioning effort (FTE) is flat over the year long transition MILESTONE 1/18 Beneficial Occupancy 7/18 First GeMPI operational (Background Monitor) 10/18 First Beta cage is screening at FAARM Interleaved transfer schedule continues through the year 1/19 All XIA alpha screening now at FAARM 2/19All GeMPIs, BetaCages now at FAARM *** Decommission Soudan LBCF 3/19 All gamma screening at FAARM *** Release Davis cavern 6/19Whole body screening in Immersion Tank *** Fully operational FAARM DULBCF to FAARM Transition

Bottoms-up Cost Estimate for all phases S4: 1 M received to make a Preliminary Design of FAARM and associated R&D PostS4: 200 k for design completion DULBCF: 8M, includes 9 years of staff & students at 5M and most of the screeners FAARM: 7.2 M in equipment, M&S, contracted structures 1.6 M in labor: 0.7M scientific staff 0.9M engineering FAARM Operations at ~ 500k/year labor Also included tasks/cost from DUSEL R&D, BGE, CDMS, etc

Cost Profile from the Project File