Planning Page for a "Centers of Excellence" Consortium in Low Background Assay and Techniques

Vision Document (March 2013)

The Vision Document linked above was requested by Michael Salamon during the Cosmic Frontier Workshop at SLAC. It presents the reasons we believe such a consortium or network is needed for rare event searches. It also sets out certain “Principles” which represent the consensus of members of the community who contributed to the discussion during the AARM, DURA, and Facilities Frontier targeted meetings. It does NOT explain how such a consortium will be run in practice, nor how much it would cost, nor how to organize the disparate groups. The purpose of this WIKI is to begin the hard work of creating the form of such an entity, eventually to be proposed from the community to DOE and NSF.

Other Resources and Documents

Detailed Planning Forum

Management Model

  • How centralized?
  • Composition of Scientific board?
  • Term limits, representation, international members.
  • Led by National lab or by University?
  • Agency reporting? How do they measure effectiveness? What's the specific relationship between the agencies and the Consortium?

Cost Considerations

Cost of technicians and general operating budget

  • Estimate number of FTE needed to run existing screeners and percent of screener time available to users
  • Estimate M&S and other infrastructure
  • Sample prep and shipping costs

Cost of Central Management

  • choose several models and cost them
  • IT support (website, screening scheduling tools, universal database, listserv)
  • Postdoc & student support
  • Senior personnel
  • Travel for collab meetings, etc

Cost recovery from user fees or subsidy

  • Determine model for subsidy assignment
  • Determine a user fee

Savings produced due to new Consortium model, compared to business as usual

  • No one has to put new screeners and R&D in their proposals - just user fees
  • Cost of maintaining screeners through other funding sources
  • Efficient use of existing screeners thru universal scheduling
  • Dedicated personnel which maintain the knowledge base, no retraining (except students)

How do we expand the suite of Screeners or funding new R&D

  • Operating Fund is provided by DOE as to a National Lab (LDRD funds) and the Consortium responds to proposals on how to use it?
  • Consortium requests proposals and selects best ones to put forward to DOE/NSF as a proposal from the Consortium?
  • How do we include new consortium members, thus adding screeners.

Available Assay Technology

Include type, percent available, sensitivity, and the FTE technicians & cost for user screening of available resources.

  • PNNL (Eric Hoppe)
    • ICP-MS - Dedicated instrument and clean room facilities for low background assays
      • Variety of materials can be assayed such as polymers, electronic components, cables and wires, metals, etc. to sub-micro Bq
    • Gamma-ray assay - Above and below ground, single and multi-xtal array HPGe detectors with radon purge
      • Above ground include 6 commercially shielded HPGe detectors (n-type and p-type), ranging from 40-75%
      • Below ground systems under development in new shallow underground lab.
    • NAA - PNNL works with WSU, OSU, and others to perform NAA when needed.
    • Materials - Production and/or preparation and handling
      • Electroformed copper produced in clean room environment in an on-site shallow underground laboratory.
      • Surface preparation, cleaning, packaging, and handling of various materials for low-background detectors.
    • Variety of other instrument capabilities for assay purposes available through the EMSL
  • Soudan (Prisca Cushman)
    • Low threshold Gopher HPGe (managed by CDMS)
      • Cost is minimal - samples changed by staff and analysis done by CDMS grad student, limited availability
    • SOLO HPGe (managed by Brown/LUX)
      • No availability at the moment
    • Muon Shielded Room with time-stamped muon tracks
      • Plenty of room under the shield and easy access to time stamp electronics to correlate with tracks.
    • Neutron Multiplicity Meter and USD LS neutron detector
  • SURF (Jason Goon)
    • CUBED HPGe low background counter at the 4850-ft level
    • Begin to accept samples in July of 2013
  • KURF (Reyco Henning)
    • 2 low background commercial HPGe detectors with Rn purge installed (See Nucl. Instr. and Methods A 642 (2011) 65)
    • Technical support provided by TUNL and a part-time graduate student.
    • Samples currently screened at no cost to experiments, however increased demand may change this.
  • LBNL (incl Oroville) (Yuen-dat Chen)
    • Surface Site: HPGe (115% n-type with muon veto), HPGe (p-type), BF3, NAI and existing shielding/low background space for R&D hosting.
    • Oroville Site (600 mwe): HPGe (85% p-type) and large existing shielding for R&D hosting including data transfer and maintenance support.
  • UC Davis (Mani Tripathi)
    • NAA using TRIGA reactors at Davis (2MW) and Irvine (0.5MW). Davis reactor allows for quick exposures in the reactor core or longer exposures at the periphery of the water tank. At the Irvine reactor we are deploying a heavy water shielded sample-holder module. This will provide x10 improvement in the thermal/fast neutron flux ratio.
    • IC-PMS This facility is owned by another group on campus. We are able to use it on a recharge basis.
    • Radon Screening A facility is being developed for use by the LZ collaboration. Not clear at this point whether there will be time available for other users.
  • NAA (Alabama) (Andreas Piepke)
  • SNOLAB (Ian Lawson)
    • 1 PGT coax germanium detector for gamma assaying, sensitivity to energies between 90 and 3000 keV, sensitivity down to 1 mBq for U and Th.
      • PGT detector usage, currently about 380 samples (note that the total may not equal 100% due to rounding), as follows:
      • Canadian Based Experiments:
        • SNO/SNO+ 27.8 %
        • DEAP 22.4 %
        • HALO 1.9 %
        • PICASSO 2.4 %
      • US Based Experiments:
        • MiniCLEAN 15.6 %
        • COUPP 10.0 %
        • DAMIC 1.1 %
        • EXO 1.4 %
        • DM-ICE 6.2 % (Non-SNOLAB experiment)
      • SNOLAB 11.9 % (Samples which are not for any specific experiment)
    • Canberra well germanium detector for gamma assaying, sensitivity to energies between 10 to 600 keV, sensitivity down to 0.2 mBq for U and 0.4 mBq for Th 0.1 mBq for 210Pb.
      • The Canberra well detector is used mostly by SNO+ and DEAP. This will change as smaller samples are counted on this counter instead of on the PGT counter.
    • Electrostatic Counters, 11 counters in operation, these are essentially alpha counters, which count the alphas from thorium and uranium decay chains. Sensitivity down to 10^-16 gU/g in the 226Ra chain.
      • The ESCs are now mostly used by EXO, although they were originally built to assay the light and heavy water for SNO. Once SNO+ is operational they will again be using the facilities. A small number of samples have been counted for other experiments such as PICASSO and MiniCLEAN.
    • Alpha-Beta counters, 8 counters available, these search for alpha-beta coincidences in the U and Th chains, sensitivity down to about 1 mBq.
      • The alpha-beta counters have been used mostly by SNO and now SNO+, but are available for other experiments.
      • Canberra coax germanium detector, this is currently being refurbished by Canberra France and should be returned to SNOLAB this Fall.
    • Summary: In general, the SNOLAB facilities are used by SNOLAB based experiments. Although the facilities are available for non-SNOLAB experiments, only DM-ICE has used the facilities. This is mostly due to the continuous queue of about 10 samples for the PGT detector from the SNOLAB experiments. Once the Canberra coax detector arrives and is setup, then additional samples can be counted and current samples can be counted longer as needed.
  • Gran Sasso (Matthias Laubenstein)
    • 10 HPGe detectors owned and operated by INFN.
    • 1 HPGe (Gator) operated by XENON, GERDA and DARWIN. The detector is p-type coaxial, 2.2 kg with sensitivity of ~mBq. 100% usage by XENON and GERDA, envisioned 100% usage by DARWIN. arXiv: 1103.2125v2
    • Details of operations, costs, etc of the facility are outlined here.
  • Kamioka (2700 mwe)
    • 1 HPGe detectors under construction by the KamLAND collaboration. This detector is expected to be for exclusive use of KamLAND, but they may consider use by other experiments on a case-by-case basis.
    • 1 HPGe detectors under construction by the CANDLES collaboration, not available to other users.
    • 3 Germanium detectors, 2 p-type and 1 n-type, operated by XMASS and SuperK, available for others with preference to XMASS and SuperK
    • ICP-MS operated by XMASS and SuperK, available for others with preference to XMASS and SuperK
    • API-MS operated by XMASS and SuperK, available for others with preference to XMASS and SuperK
    • Many Rn detectors to measure emanation of Rn from materials, operated by XMASS and SuperK, available for others with preference to XMASS and SuperK
  • Japan (Surface)
    • 1 HPGe detector operated by KamLAND, not available for other users.
    • 1 HPGe detector operated by CANDLES in Osaka, not available for other users. Sensitivity is a few mBq/kg for CaF2, relative efficiency is 35%.
  • Jinping (Xiang Liu, Zing Zhi)
    • 1 HPGe detector operated by PandaX, not available for other users.
    • 1 HPGe detector operated by CDEX, not available for other users.
      • N type HPGe made by Canberra, relative efficiency :40%
      • Detector Sensitivity: 40~2700kev, integral bkg counts rate is about 0.6 cpm; MDA is about mBq/kg for common gamma peak (eg.609keV) from environment nuclides.
    • 2 HPGe detectors to be installed by end of 2013.
      • Model BE6530 by Canberra
      • CDEX will have preference, but 30% availability will be reserved for other users.
  • LSM, Modane (Pia Loaiza)
    • 12 HPGe detectors, details in attached file (pdf). The detectors are 100% dedicated to use by SuperNEMO, EDELWEISS and other experiments situated in Modane. However, Mafalda and Hellaz may be able to do work at the level of 5-10% time for other in the future.
  • Laboratario Subterraneo de Canfranc (Iulian Bandac, Alessandro Bettini and Yolanda Labarta)
    • 5 HPGe detectors installed and operational.
    • 2 HPGe detectors to be installed by summer 2013.
    • Details of the detectors in attached file (pdf). The detectors are currently in 100% usage by LSC experiments. However, they are interested in working with experiments outside of LSC.
    • All detectors are ~2kg, p-type close-end coaxial produced by Canberra. Each detector has a shield consisting of 5 cm or 10cm copper and 20 cm of very low activity lead. Nitrogen gas is flushed inside a methacrylate box to avoid airborne radion. The radon level inside the lab is ~ 80 Bq/m^3.

Integrated Screening Scheduling

  • Creation of a centrally-managed website with all screeners and availability listed
  • How do we prioritize requests?
  • Model for contacting available screener and submitting a request: Let each center define their access model.
    • PNNL
    • Soudan
    • SURF
    • KURF. Contact Reyco Henning via email ( The throughput is low enough that this model should work.
    • LBNL (incl Oroville)
    • NAA (UC Davis)
    • NAA (Alabama)

Policies on Open Access and Materials Database

  • All data taken with subsidized screeners is immediately entered into database
  • Data on proprietary screeners will negotiate when their data will become public.
  • Do we want to allow for some sensitive screening which is NOT public, but then they pay more for a non-disclosure agreement?
  • Policies for papers which use this data?
consortium.txt · Last modified: 2013/12/18 13:12 by prisca