1. U.S. Low Level Counting Facilities Status and Plans LRT 2004, Laurentian University Dec 12-13, 2004 Prisca Cushman University of Minnesota

2. How do we optimize science and technology choices before DUSEL, for DUSEL, and in addition to DUSEL? Screening for existing experiments (and security-related appl.) Underground testing of prototypes for DUSEL technology choices Screening for the proposed experiments Development of high purity materials Clean rooms, radon scrubbing, shielding, infrastructure R&D now for a future DUSEL LBCF How can we share resources in a tight budgetary climate? How can we exploit economy of scale? In Progress: Working Group on Low Background Counting Facilities (NSF Solicitation 1 Proposal)

3. First Job: Gather Information Identify current and future needs Sensitivity required: Low Level vs Ultra-Low vs Extreme-Low Type of screening:  Sample size or material Best technique may not be “counting” NAA (counting + radiochem lab) ICPMS, AMS ($$) RBS, PIXE, Auger, SIMS

4. Our first try already anticipates backlogs Turnover at 2008 reflects our ignorance As limits improve, migration from LL  UL and UL  XL (this is not properly folded in) Many of the LL category could explore other techniques MJ R&D MJ Prod MJ Ops EXO R&D EXO Prod EXO Ops Cuore R&D Cuore Prod Cuore Ops Moon R&D Moon Prod Moon Ops SuperDMS R&D SuperDMS Prod SuperDMS Ops Clean R&D Clean Prod Clean Ops Xenon R&D Xenon Prod Xenon Ops R&D1 R&D R&D2 R&D KamLAND R&D KamLAND Prod KamLAND Ops Borexino R&D Borexino Prod Borexino Ops UNO R&D UNO Prod UNO Ops KillerAp 1 R&D KillerAp 1 Prod KillerAp 1 Ops KillerAp 2 R&D KillerAp 2 Prod KillerAp 2 Ops KillerAp 3 R&D KillerAp 3 Prod KillerAp 3 Ops KillerAp 4 R&D KillerAp 4 Prod KillerAp 4 Ops Each collaboration should define needs and then give to us… Categories used

5. Gather Information – cont. Identify existing counting facilities in the US Analysis centers at most Universities User fees – cheaper for University faculty Commercial Labs Longer turn around, more expensive, more standardized “Use for Others” at most national labs (Oak Ridge, LANL, BNL) A few shallow  middle depth sites open for users LBL Bldg72 and Oroville Dam – now LOMO at PNNL - soon Deep screening sites are only in development stage WIPP (MEGA ) Soudan:  -screening capability in SOLO Plans to create a multi-purpose LBCF Really, Really Deep sites are DUSEL era DEPTH

6. Sensitivity for US Sites Surface counters LBL Bldg 72, PNNL, and many other places etc. Shielded on surface PNNL 17-A LBNL Oroville 2000 + mwe Soudan, MEGA LoMoCF estimate

7. Berkeley Complex: Surface and Shallow Site under same umbrella organization: Institute of Nuclear and Particle Astrophysics STAFF Kevin Lesko Al Smith Dick McDonald Donna Hurley

8. Throughput determined by number of Ge detectors Bldg72 has NaI counters and a 130% HPGe, Oroville has a 80% p-type HPGe Major User: SNO (screened virgin and machined acrylic, plastic resins, PMT envelopes, internal components, stainless steel, etc.) Also Clean room preparation and operation, sample handling procedures Sensitivity is currently limited by detector contamination Bldg 72 (LBL) Dam (140 mi) from LBL

9. PNNL – UW Complex: Surface + 17-A ULB + new initiative at Lower Monumental Dam 1 hr from PNNL 37 meters of overburden Operated by US Army Corp of Engineers

10. Inside LoMo Counting Facility: Currently being used as cosmogenic isolation space for copper stock and MEGA parts Plan is to install gamma screening in lead cave. Funding is in place. 4’ 1’ 4’ 1’1’1’ Water trough ~8’ Person Access 4-person elevator access Two sets of 3 HPGe counters with active cosmic veto shield UW J.A. Formaggio J.F. Wilkerson PNNL C.E. Aalseth R.L. Brodzinski T. Hossbach H.S. Miley J.L. Orrell

11. WIPP DOE Facility Impressive infrastructure Modest depth (1600 mwe) Science as add-on to primary mission Low background counting lab being built MEGA-SEGA

12. LANL/WIPP complex: 2 connex for storage and office space Detector Hut and electronics room

13. The highlight is the MEGA detector: combination R&D for Majorana and ultra-low screener

14. SEGA underground by next summer (not a screener) Assembling MEGA at WIPP now. 1 st detector may take data by end of January Completed in a couple years.

15. The major arguments for placing it at Soudan are Availability: 40 ft x 35 ft x 100 ft experimental hall surrounded by a 99% efficient muon veto shield. Infrastructure: The Soudan Underground Laboratory is a working science lab: (MINOS, CDMS, SOLO gamma-screening facility) Cost: Cheap (~ $2 M) due to existing infrastructure and working muon shield A multiple-user facility is far more cost efficient. Self-sufficient: operating budget pays for itself Timescale: 2 years if not funding limited. Staged plan starting NOW. Low background Screening and Prototyping Facility at the Soudan Underground Lab Draft Proposal at http://www.hep.umn.edu/~prisca/soudan

16. Last Soudan2 proton decay calorimeters (at back) were removed Nov 23 rd 2004 SOLO HPGe Diode M (35%) Twin (75%) UF detector (100%)

17. Four HP Ge detectors for gamma screening. Two in existing lead-shielded SOLO facility (Brown, PNNL) Third from U. Florida startup, 4 th Clover Well Detector (NSF MRI) Two alpha/beta screeners (via alternate funding) neon gas MWPC (Caltech, CWRU, FNAL) triggered expansion cloud chamber (UCSB, UMinn) Underground electroforming facility to make high purity copper (Reeves & Sons via awarded SBIR) Ge Detector fabrication (pending SBIR with Princeton Gamma Tech) Clean Machine shop Water tank with multiple top-loading ports in clean room on top Multipurpose clean room with shielded bays for prototypes Radon-scrubbing for all clean rooms Full Proposal includes the following features

18. Ante- room Multi- purpose clean room Clean room over tank Water ports with crane Electro form 40 ft Upper mezzanine above tank top User shielding Clean room over tank anteroom Clean room Water tank Shielded bays mezzanine anteroom radon scrubbing plenum. stairs current mezzanine Muon veto shield 100 ft Drawings and Design Consultation: Short Elliott Henderson Engineering, Inc

19. At Soudan, it reduces cosmogenic neutron flux to ~ 0.007 mdru roughly equivalent to 4000 mwe cavern depth Cost is the same as one lead castle, but it will serve multiple users. It can be upgraded (limited by water purification) or filled with Liq. Scint Provides an R&D example for DUSEL LBCF If we build in stages, we will always use lead caves, but the water tank advantage is:

20. Strategy for Soudan LBCF Create minimum facility now (DOE University supplements for infrastructure) Provide world class gamma screening via 2005 NSF MRI Provide novel beta screeners through CDMS collaborators (or possible MRI 2006) Take this next year to Increase size of collaboration Attend NSF Solicitation 1 and LRT2004 Modify design according to input and new users That’s You! Put in complete proposal next Fall ‘05

21. The following ongoing work has been funded Soudan2 Removal DONE Veto Shield refurbishing Pressure tests finished, tubes repaired, preamps tested New DAQ: Location and Time stamp (1MHz osc + GPS pps) for every 2-plane coincidence Clean room on Mezzanine (CDMS SiLi and BF detector) Clean room in back of Mezzanine (Reeves electroforming & detector) Full Project File (BOE and engineering input) A process to accept new experiments: (fee structure, management, EPS) EPS Signers for this winter Medtronics: cosmogenic soft memory errors SBIR to do copper electroforming underground (Jim Reeves) 2nd SBIR for a low background detector (microBq/kg) to test copper COUPP (superheated liquid bubble chamber for dark matter)

22. Experimental Planning Statement for the Low Background Counting Facility A statement with the information detailed below, together with the signature sheet, must be submitted to the Soudan Underground Lab Manager before any experiment can be approved for installation in the Low Background Counting Facility. This will ensure that any new experiment does not interfere with either the of the two existing large experiments or with public tours, as well as reviewing safety and code-related issues. 1. Project Title and Description, incl. list of collaborators, institutions, and funding sources. 2. Experiment Area and Infrastructure Needs. This section should include physical area needed, both underground and on the surface, connections needed between surface and underground installations, electrical power needs, LAN bandwidth, and any special air handling requirements. There should also be list of number phone or fax lines needed. Depending on the area needed or type of the experiment, are there additional fire or life safety infrastructures needed? 3. Project Schedule Schedule should contain any construction period needed for infrastructure, detector assembly, operation period and removal of experiment. An estimate of access (and access schedule, including on-call emergency access) should be included such that hoist costs directly related to the experiment can be properly calculated. A description of the load size and weight of the cage is available. 4. Hazard Analyzes A complete list materials to be brought underground and waste products to be removed. Any possible physical hazards should be listed. All materials should have MSDS sheets appended to this document. Any material handling issues should also be noted. Assessment of this issues, especially the ones that fall under the safety category, need to be addressed by both the U of M and DNR who are responsible for site safety. 5. Minecrew Labor An estimate of minecrew labor needed should include any construction or operation manpower requirements. As a general rule, all non carry-on equipment must be moved underground by the minecrew. A trained and designated cage rider must be present underground at all time if access for non-standard shifts is needed. 6. Surface Space Required List any space usage needed in Surface Building for staging or remote operation, including control rooms and computers (there is a fiber optic connection to the underground lab). Also list any space required that cannot be accommodated inside the surface building for parking, staging or general material storage.

23. Project Title:____________________________________________________ Prof. Earl Peterson ______________________________________ University of Minnesota Soudan Underground Lab Director eap@mnhep.hep.umn.edu Mr. William Miller ______________________________________ University of Minnesota Soudan Underground Lab Manager miller@sudan.umn.edu Mr. Paul Wannarka ______________________________________ Department of Natural Resources Soudan Underground Mine State Park Manager paul.wannarka@dnr.state.mn.us Dr. Regina Rameika ______________________________________ Fermi National Laboratory MINOS Operations Manager rameika@fnal.gov Dr. Dan Bauer ___________________________________________ Fermi National Laboratory CDMS II Project Manager bauer@fnal.gov Prof. Priscilla Cushman ____________________________________ University of Minnesota Manager of the Low Background Counting Facility prisca@physics.umn.edu

24. What should a DUSEL LBCF look like? Soudan/WIPP are pre-DUSEL Address screening issues NOW Could be expanded into a DUSEL or Used as R&D for DUSEL design Supplement screening & prototyping in DUSEL era. Homestake NUSL Reference Design Report WBS 6.1 (Low-level counting facility) NUSL White Paper (Nico, Piepke, Shutt)

25. Figure E-16 from the Homestake Reference Design Secure lab Emanation and leaching laboratory (TBA) Pool 2 Gd-loaded liq. Scint for neutron sensitivity or Mini-Borexino for U/Th down to 10 -16 g/g Pool 1 12 m cube – ultra-pure water NAA Laboratory + general environmental sample handling Built-in liq. Scint acrylic thimble ports read out by PMT’s for U/Th down to 10 -14 g/g

26. University of Minnesota Intercollegiate Grant 1.Seek out other user communities for LBCF 2.Coordinate low level counting/analysis across sites website this spring tie it to the solicitation 1 work Examples of other user communities involved: C. Alexander (Geology) Tritium and 14 C in groundwater C. Lungu (Environmental Health Sciences) & Minnesota Pollution Agency Radioactive environmental sampling (accidental release of radio-isotopes) Exposure assessment studies ( 14 C as a tracer of particiulate lung burden) Epidemiological studies of uranium workers (tissue samples) Large Lakes Observatory, The St Croix River Watershed Research Center, Florida Dept of Fisheries and Wildlife short-lived isotopes for sediment dating These “other” users need well-type HPGe, chemical separation, sample handling AND beta-counting applications ( 14 C, 3 H)

27. Conclusions and not-so-random Thoughts Immediate need for more screening facilities – we cannot wait for DUSEL Most samples can use shallow/shielded sites and many could use other techniques, but a growing number require the shielding of a deep site One-stop shopping would be very convenient sorting samples, pre-screening, follow up techniques, cosmogenic/radon-free isolation storage Plus: industry spin-offs (electroforming, detector development) cost effective (manpower, infrastructure, scheduling) fosters R&D and collaborative efforts To be complete, such an analysis center should have deep capabilities. Collaborations can use European/Asian facilities BUT backlogs still exist, local sites are convenient, small R&D efforts and non-int’l groups left out Symbiosis possible: geology, hydrology, public health, environmental sciences are growing users of isotope analysis and dating. Multiple Sites are a Good Thing – but some complementarity is desirable.