S4 Proposal for a Liquid Argon Detector at DUSEL Marvin L. Marshak/University of Minnesota Thanks to Bonnie Fleming for multiple slides. 1

LAr S4 Collaboration Brookhaven National Laboratory, CNA Engineering, Colorado State University, Dunham Associates, Fermilab, Indiana University, Itasca Consultants, Michigan State University, Miller Dunwoodie Architects, St. Mary’s University, Tufts University, University of Minnesota—Duluth, University of Minnesota—Twin Cities (Physics and Mechanical Engineering), University of Texas—Dallas, Yale University 2

Goals of the S4 Work Develop an S5 Proposal for a 5 kT LAr Detector by late Winter/early Spring 2010 Make progress on research, engineering, design regarding major components of S5 Proposal Physics capabilities of LAr Detectors Ability to design, estimate cost and manage the construction and installation of a 5 kT LAr Detector Ability to design, estimate cost and manage the interface between the 5 kT LAr Detector and DUSEL Ability to demonstrate safe installation and operation of a 5 kT LAr Detector 3

Physics Capabilities LAr technology appears scalable to large fiducial masses and is complementary to WC Produces fine-grained “pictures” of events Ionization detector; not subject to Cerenkov energy threshold For neutrino oscillation physics, LAr is better able to reduce backgrounds for v e appearance. An LAr Detector is equivalent to a WC Detector with substantially larger mass For proton decay, LAr is directly sensitive to supersymmetric neutrino kaon modes 4

Search for CP Violation 5

Search for Proton Decay 6

Designing a 5 kT LAr Detector Past and Ongoing Work ICARUS at Gran Sasso R&D program at Yale ArgoNeuT installed at Fermilab 20 T Purity Demonstrator at Fermilab MicroBOONE at Fermilab (175 T LAr; data in 2011) 7

Designing a 5 kT LAr Detector Key issues for Detector Design Cryostat: How many? Vacuum or foam insulation. Foam is cheaper to construct but has more heat leaks, microphonics, cannot be initially evacuated [Indiana] Electronics: Cold electronics reduces cabling issues and cost, but requires operation with high reliability in hostile environment [BNL/Michigan State] TPC, PMT and HV: need long drifts [large voltages], reliable triggering [UCLA] Argon Purification: Need to achieve high purity to sustain long drifts [Entire Collaboration] 8

Designing a 5 kT LAr Detector Key Issues for Detector/Lab Interface Dedicated or shared lab Ancillary or integrated space for support systems Bringing cryostat pieces underground and assembling cryostats Bringing the argon underground Facilities for liquid nitrogen, if required Electrical and heat loads Normal and emergency venting Storage of argon if a cryostat needs to be emptied Extensive safety analysis and mitigation design 9

Cryostat/Cryogenics – Organization J. Urheim is coordinating efforts toward cryostat conceptual design. For now, don’t have a coordinator for cryogenics, but many people w/ real experience are involved. Have just started bi-weekly series of phone meetings – 1PM Central; so far participants include: Larry Bartoszek (Bartoszek Eng), Carl Bromberg (Michigan State) Bonnie Fleming (Yale), Walt Fox (Indiana), Bob Kephart (FNAL), Chris Laughton (FNAL), Marvin Marshak (Minnesota), Bill Miller (Minnesota), Stephen Pordes (FNAL), Rob Plunkett (FNAL), Jack Sondericker (BNL), Jon Urheim (Indiana), Hanguo Wang (UCLA) Additional participation is welcome/needed !!

Cryostat/Cryogenics – Initial Activities Aim is to develop a conceptual design on timescale of a year. Need S4 proposal to be successful to have a chance… Starting from a blank slate: looking to experience w/ MicroBooNE, ICARUS, other efforts, but must confront unique features (size/scalability, underground construction, safety issues) head on. Currently reviewing existing ideas (simple geometries, LNG tanker ships, LANNDD-like modular TPCs, etc…). Some key questions : Modular or Monolithic ? Vacuum or passive insulation ? Transport of materials & cryogens underground ? At the same time must develop a framework for concept development, specifically : Requirements Documents – what the systems need to accomplish Constraints Documents – what the DUSEL environment dictates Materials & Fabrication details– what the options are for implementation

Cryostat/Cryogenics – Possible Timeline March / April ’09 Develop requirements/constraints/etc documents Review existing concepts April / May ’09 Arrive at cartoon level strawman concept(s) for baseline Summer ’09 Provide detail for baseline concept(s) Will require considerable coordination w/ DUSEL infrastructure & cavern construction efforts Hopefully real engineering support becomes available at this point; will need to understand how to best factorize the design process. Fall ‘09 and beyond Develop conceptual design to a level that can be costed

Longer Range Plans 13

Longer Range Plans 14

LAr S4 Summary Proposal submitted January 9 Builds on past and ongoing LAr development initiatives Deep underground location poses challenging issues; significant engineering work will start soon Major milestone is sufficient knowledge and design work for DUSEL Proposal in Spring