Dark Matter Searches

1. Dark Matter Searches Summary of NSF Dark Matter Projects Direct Detection (including co-funds with DOE-HEP) Jim Whitmore Ani Aprahamian, Jon Kotcher at P5 Meeting at Fermilab September 24-25, 2007 NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

2. NSF PNA Funding in FY07 Note: in $k Note: all of these values include base group funding NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

3. DMSAG Report July 5, 2007 NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

4. DMSAG Report • Recommendation 1: Program and Funding • To realize this program on an optimal time scale, the committee recommends that DOE and NSF increase funding for the direct detection of dark matter from the present ~$2-3M to ~$10M annually as soon as possible. The prospect of detecting dark matter while the LHC is operating amply justifies this increase. Such a figure is also consistent with the recommendations of P5 and EPP2010. • See Table of funding levels since FY2002: • We anticipate that the funding level will be increased over the next few years NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

5. WIMP-detection Experiments Worldwide SNOLAB Picasso DEAP SuperCDMS Soudan CDMS II DUSEL LUX CLEAN SIGN XMASS FNAL COUPP IGEX KIMS SUF CDMS I LiF Elegant V&VI Boulby NaIAD ZEPLINI/II/III DRIFT 1/2 Gran Sasso DAMA/LIBRA CRESST I/II Genius TF CUORICINO XENON WArP LSM EDELWEISS I/II ORPHEUS CanFranc IGEX ROSEBUD ANAIS Funded NSF ArDM Figure from D. Bauer, TAUP NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

6. DMSAG Report = NSF funding Figure from S. Elliott, HEPAP, Feb 07 NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

7. Removing Muon-induced Neutron Background • Neutrons from cosmic rays are irreducible background • At SUF • 17 mwe • 0.5 n/kg-d • At Soudan • 2090 mwe • 0.5 n/10kg-y • At SNOLab • 6060 mwe • 0.2 n/ton-y CDMS I - Stanford CDMS II - Soudan ZEPLIN, DRIFT XENON10,WArP Log10(Muon Flux) (m-2s-1) PICASSO, SuperCDMS Depth (meters water equivalent) Figure from D. Bauer, TAUP NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

8. DMSAG Report • Recommendation 2: ADMX • The committee recommends that the ADMX collaboration be supported to operate the existing detector and, pending success of phase I, to take the necessary steps to reach greater sensitivity through lower system temperature. • NSF has no involvement with ADMX NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

9. DMSAG Report • Recommendation 3: CDMS • If funding is not sufficient for the rest of the program we have outlined, we recommend that the decision to go forward with supertowers 3-7 and installation of SuperCDMS in SNOLAB be considered in the broad context of a full evaluation of the field to be completed by mid-2009. • We have agreed to fund CDMS for the completion of CDMS-II; and • to fund two S-CDMS super-towers at Soudan (FY07-09), at their requested level, subject to available funding and satisfactory reviews (Review in Fall 2007 – Spring 2008) • No commitment (today) for anything further NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

10. DARK MATTER: SCDMS • S-CDMS (with DOE, Fermilab) at Soudan • Currently approved, subject to a review Fall 07 – Spring 08, for 2 super-towers Limit 1.7x10-43 cm2 at 60 GeV • NSF: $9.88M constr. +$3.0M in FY08-09 • Ge: detect low temperature phonons NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

11. DARK MATTER SEARCHES Large A best since for SI s ~ A2 for low nuclear recoil energy Xe “easy” cryogenics at ~165K NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

12. DMSAG Report • Recommendation 4: Noble Liquid Detectors • a) The sub-panel supports the development of one two-phase xenon-based detector at the 100 kg scale and above. • b) The sub-panel supports the development of detectors using liquid argon and/or liquid neon technology. WARP and miniCLEAN/DEAP represent two quite different technologies in their application to liquid argon. Both of these techniques should be explored to discover which has greater potential. • (a) Xenon “two similar projects” issue: • We will fund XENON10+ (upgrade) in FY08 • We will consider some funding for the LUX initiative in FY08, in coordination with DOE, following review • We support Zeplin-II PIs at the $180k level in FY07 • (b) We are funding WARP at the ~$600k level in FY07 and $300K for FY08-09 • No current funding to DEAP/CLEAN NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

13. NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

14. DARK MATTER: XENON10 • XENON10 (with DOE, Germany) at LNGS • 2-phase Xe 5.4 kg fiducial mass • 3-D position sensitive TPC • NSF has funded $5.59M (FY02-07) • With 136 kg-day exposure: • 4.5x10-44 cm2 at 30 GeV NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

15. DARK MATTER: ZEPLIN-II • ZEPLIN-II (with DOE, PPARC) at Boulby (UK) mine • 32 kg 2-phase Xenon • Measures both primary and secondary scintillation • NSF providing $890k over 7 yrs (FY02-08) • 6.6x10-43 cm2 at 65 GeV from 225 kg-day exposure NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

16. DARK MATTER: WArP • WArP (with INFN, Poland) • 2-phase LAr 140 kg fiducial mass (under const.) • At LNGS • Pulse shape/ionization/scintillation discrimination • NSF is providing $1.55M (FY06-09) • Current limit ~ 7x10-43 cm2 at 100 GeV with 3.2 Kg and 96.5 kg-day exposure 140 kg Operation in early 2008 NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

17. DMSAG Report • Recommendation 5: Superheated Liquids and Directional Sensitivity • a) The sub-panel recommends the development of superheated liquid detectors. The program proposed by COUPP appears to be well balanced and has recently been approved by the Fermilab PAC. • b) On the basis of the performance and background levels presented by the DRIFT collaboration, the sub-panel recommends the development of a single prototype detector module with the principal goal of demonstrating track reconstruction and directionality determination. • We have been supporting the COUPP program with a CAREER award that started in FY03 and the DRIFT program with one that started in FY06 • (a) We are currently supporting COUPP at the level of $320k in FY07 • (b) We are currently supporting the DRIFT project at the level of $647k in FY07 (incl. DUSEL R&D) NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

18. DARK MATTER: COUPP • COUPP (with DOE/Fermilab) • Room temperature bubble chamber • 1.5 kg of superheated CF3I (350 ft deep NUMI tunnel at Fermilab) • NSF has funded $640k (FY03-07) • pe rejection 10-10 for Er ~ 10 keV • 52 kg-day run • SD limit 2.6x10-37 cm2 @ 50 GeV NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

19. DARK MATTER: DRIFT-II • DRIFT-II (with PPARC) • a low pressure gaseous TPC • target carbon disulphide (CS2) • DRIFT is designed for scalable target mass and dE/dx background discrimination. • The use of low pressure gas and position sensitive readout means DRIFT is sensitive to the direction of incident particle. • at Boulby (UK) mine • NSF has provided $2M in FY02-07 NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

20. DMSAG Report • Recommendation 6: DUSEL • We strongly support the construction of a U.S. Deep Underground Science and Engineering Laboratory (DUSEL), which could host ton-size or greater direct dark matter detection experiments. • We agree NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

21. DMSAG Report • Recommendation 7: Scanning Facilities • We recommend additional underground scanning capability to alleviate the impending shortage, increase the sensitivity, and expedite the scanning of materials for the new generations of detectors. Ideally, a comprehensive facility, as described in the DUSEL S1 report, should be located in the DUSEL site. • With DUSEL R&D funds, we have supported such activities in FY07 at the $433k level (but at various sites in the US) NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

22. DUSEL R&D FY07 *(39Ar/Ar)und / (39Ar/Ar)atm = 0.00±0.05 Total (NSF/ DOE-HEP/ DOE-NP) $3.7M NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

23. DMSAG Report • Recommendation 8: Priorities • Following on the above recommendations, if the comprehensive program we have described above is not able to be fully funded, then we recommend that the funding priorities during the next few years be allocated as follows: • 1. Equal priorities between (A) and (B): • A) Continuing the on-going CDMS and ADMX experiments and the initial construction of SuperCDMS in Soudan with two super-towers. • We are supporting CDMS and S-CDMS at the two-supertower level • B) Funding the expansion of the noble liquids with priorities i), ii) and iii): • i) The expansion of the liquid Xenon experimental efforts to their next level. • We are supporting XENON10+; considering other possibilities (LUX) • ii) The U.S. participation in the WARP detector development. • We are supporting WArP at a $600k level in FY07 • iii) The next stage of the CLEAN Argon/Neon detector development. • We have no involvement with DEAP/CLEAN at present NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

24. DMSAG Report • Recommendation 8: Priorities (Cont.) • Following on the above recommendations, if the comprehensive program we have described above is not able to be fully funded, then we recommend that the funding priorities during the next few years be allocated as follows • 2. The development of superheated liquid detectors and detectors capable of determining WIMP direction. Although these ideas have great promise, they still have significant R&D questions remaining to be answered. • We are supporting COUPP and DRIFT-II • We believe that many of the questions associated with the longer-term direction of the experimental efforts will be resolved during the next few years, provided that the current support continues and our recommendations are implemented, and that a program review in or around 2009 will be necessary. • We are anticipating another Dark Matter field review sometime in the next 1-2 years NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

25. Summary of DM projects NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

26. NSF PNA Program Note: all of these values include base group funding NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

27. NSF PNA Program BACKUP SLIDES NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

28. Summary of DM Projects (From P. Belli, TAUP2007) NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

29. XENON Program : 2007-2008 New Collaboration: Columbia, Coimbra, LNGS, Rice, University of Zurich • New detector to replace XENON10 in current shield at LNGS is under construction • 150 kg total (70 kg in target) procured. Purification for ppt level of Kr started • Low activity PMTs and cryostat, active LXe veto, cryocooler and feed-throughs outside shield factor ~100 reduction in total gamma background compared to XENON10 • 1 inch PMTs for good event XY localization and volume definition • Systematic screening of components with dedicated HPGe at LNGS • Optimized light detection for 5 keVr threshold 150 kg • New measurements of QF from 4- 40 keVr with optimized LXe detector carried out in Summer 07. • Data analysis ongoing. Results to be published shortly. (From E.Aprile, TAUP2007) NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

30. Summary of DM projects Projections: CDMS Soudan 2007 S-CDMS 25 Kg (7-ST) XENON 100 (2008) (From E.Aprile, TAUP2007) NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

31. Summary of DM projects Projections: • XMASS 800 kg • 1-ton LXe, • DM search 10-45 cm2 • Status: • Budget funded this year • 2-year construction • Start measurements in 2009 (From K.Abe, TAUP2007) NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

32. DARK MATTER: COUPP • SD limit 2.6x10-37 cm2 @ 50 GeV • SI limit not competitive at present NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007

33. Depth vs Volume Underground DUSEL expectation Fermilab First suite extensions COUPP CDMS PICASSO DRIFT, ZEPLIN-II XENON10, WARP From Deep Science (2006) Report NSF Dark Matter Program P5 Meeting, Sept 24-25, 2007