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Listening for the Dark

Listening for the Dark. Harry Nelson UCSB. Plan. Massive Dark Matter Direct Detection Xenon CDMS Future. Metals (us).  0.01%.  0.5%. Visible Baryons. Dark Baryons.  5%. Cold Dark Matter (WIMPs?).  25%. Cosmological Constant .  70%. `We Declare a New Order’ (Joel Primack).

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Listening for the Dark

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  1. Listening for the Dark Harry Nelson UCSB

  2. Plan • Massive Dark Matter • Direct Detection • Xenon • CDMS • Future Penn State Colloquium

  3. Metals (us) 0.01% 0.5% Visible Baryons Dark Baryons 5% Cold Dark Matter (WIMPs?) 25% Cosmological Constant  70% `We Declare a New Order’(Joel Primack) Penn State Colloquium

  4. v; = v/c r Penn State Colloquium

  5. Penn State Colloquium

  6. b = 0.488 ± 0.009 a M= (1.85 ± 0.06) 1030 kg Penn State Colloquium

  7. Planets about sun Msun = (1.85 ± 0.06) 1030 kg Moons about Saturn MSaturn = (5.5 ± 0.2) 1026 kg Stars w/r Galaxy Center: v/c =  constant 0.7 10-3 Penn State Colloquium

  8. R is the distance from center v vis the speed (tangential) R Galactic Dark Matter Penn State Colloquium

  9.     Honma and Sofue, 1996      v      220 km/s         :v0=180 km/s Without the Dark Halo (Binney & Tremaine)     R What about our home galaxy (Milky Way)? Penn State Colloquium

  10. Sun: moves in plane of disk v/c = 0.7 10-3 Particles in `halo’: 3-d  = mc2 n 1/3 GeV/cm3 (1/2 of total mass density) Maxwellian/Gaussian (simple) v/c = 0.7 10-3 Milky Way: mainly a dark cloud Bulge Disk Penn State Colloquium

  11. v/c = 0.7 10-3 We use Germanium, A=73, mc2=67.6 GeV; others: Si, S, I, Xe, W Design a Particle and an Experiment 0 v/c = 0.7 10-3 Neutral: cool particles neutral – , n, , K0, Z0, H0… ER½ mGec2 2  ½ 68 GeV  ½  10-6  20 keV  x-ray energy ! Easy! Massive: Mc2100 GeV hinted at by accelerator data `Weak Scale’ Penn State Colloquium

  12. Arguments for  characteristic of weak interaction • Particle physics… chose Mc2 100 GeV, `Weak Scale’ • Big Bang… independently implies weak cross section as well… Coincidence(s)… or Clues ??? Penn State Colloquium

  13. Donald H. Perkins, 1987 What is the weak interaction cross section? Penn State Colloquium

  14. Rate governed by scattering cross section,  Penn State Colloquium

  15. 0 A = # neutrons + # protons 0 Indistinguishable Density of States: Coherence, density of states enormous bonus! Scattering off a proton…. …. Hopeless! Penn State Colloquium

  16. Rate of Main Background Rate about 103 / (kg-day) !!! Shield… but that radioactive too Strategies: DAMA… huge target mass (100 kg), look for astrophysical modulation CDMS… small target mass (few kg) distinguish electron from nucl. recoil Penn State Colloquium

  17. Signal Shape MWIMP=100 GeV   10-42 cm2/nucleon A2 Silicon, Sulphur Germanium Iodine, Xenon Nucleus Recoils Er Slope: Maxwell-Boltzmann WIMPs in Galaxy Diffraction 0 Penn State Colloquium

  18. Catalog of Direct Detection Experiments Indirect Detection: Super-Kamiokande, Amanda, Ice-Cube, HEAT, GLAST, Egret… Look for astrophysical neutrinos, gammas From WIMP annihilation Penn State Colloquium

  19. Background Electron Recoils Er v/c  0.3 Sparse Energy Deposition  Direct Detection: Signal and Main Background Signal Nucleus Recoils Er v/c  710-4 dense energy deposition efficiency low distinct energy scale 0 (calibrate: neutron) Differences the Basis of Particle ID Penn State Colloquium

  20. ionization Q H phonons L scintillation IGEX, DRIFTI, II CDMS, EDELWEISS ZEPLIN II, III, MAX, XMAS, XENON CRESST I, PICASSO, COUPP NAIAD, ZEPLIN I, DAMA CRESST II, ROSEBUD Tim Sumner Penn State Colloquium

  21. – Bernabei et al. – Arneodo et al. – Akimov et al. – Aprile et al. – LIP work Lindhard Hitachi E. Aprile et al., arXiv:astro-ph/0503621 Xenon – nuclear recoils give 1/7 scintillation/energy,compared to electron recoils (``quenching’’)…. Sets recoil energy scale Tim Sumner Penn State Colloquium

  22. Nucl. Recoil Zeplin 1 – Scintillation Alone Electron Recoil 125 keV 30 keV 30 keV Nuclear Recoils – Faster Risetime… 3.2 kg Xe Risetime (ns) Penn State Colloquium

  23. 300 kg-days CDMS: 100 kg-days Zeplin-I Limit- Background Weakens 10-42 cm2 Penn State Colloquium

  24. 2-Phase (Liquid/Gas) Noble … Ar or Xe Nuclear Recoil S1 S2 S2 Electron Recoil S2 S1 S1 Penn State Colloquium

  25. XENON Gamma + neutron source Gamma source Zeplin-II Zeplin-II Preliminary Preliminary Penn State Colloquium Aprile et al. 2005

  26. Analysis…. • Appears scalable • However, unforeseen backgrounds are the rule as sensitivity increases • Promising… ZEPLIN-II and Xenon-10 soon deployed in deep sites Penn State Colloquium

  27. ER10’s keV Holes Electrode Implants e-  E 0 CDMS: Adapt Traditional Ionization Detector 1 cm Germanium (or Silicon) 7.6 cm ¼ kg (1/10 kg) What rate? (in, say, 1kg) Backgrounds? ….…. Gamma rays, neutrons, surface beta-decay Penn State Colloquium

  28. Experiment CDMS (shallow) DAMA (old!) 1/10 9/10 Our Hunting Ground Weakly Interacting Massive Particle Theory SUSY, various constraints including Big Bang Gaitskell/Mandic Penn State Colloquium

  29. DAMA – Exploit Annual Modulation Signal: higher rate in June, lower in December Background: constant in time Penn State Colloquium

  30. CDMS Collaboration (Mar. 2002) Penn State Colloquium

  31. CDMS Collaboration • Brown University • M.J. Attisha, R.J. Gaitskell, J-P. F. Thompson • Case Western Reserve University • D.S. Akerib, P. Brusov, C. Bailey, M.R. Dragowsky, D.D.Driscoll, S.Kamat, A.G. Manalaysay, T.A. Perera, R.W.Schnee, G.Wang • University of Colorado at Denver • M. E. Huber • Fermi National Accelerator Laboratory • D.A. Bauer, R. Choate, M.B. Crisler, R. Dixon, M. Haldeman, D. Holmgren, B. Johnson, W.Johnson, M. Kozlovsky, D. Kubik, L. Kula, B. Lambin, B. Merkel, S. Morrison, S. Orr, E.Ramberg, R.L. Schmitt, J. Williams, J. Yoo • Lawrence Berkeley National Laboratory • J.H Emes, R. McDonald, R.R. Ross, A. Smith • Santa Clara University • B.A. Young • Stanford University • P.L. Brink, B. Cabrera, J.P. Castle, • C.L. Chang, J. Cooley, M. Kurylowicz, • L. Novak, R. W. Ogburn, M. Pyle, T. Saab, • A. Tomada • University of California, Berkeley • J. Alvaro-Dean, M.S. Armel, M. Daal, J. Fillipini, A. Lu, V. Mandic, P.Meunier, N. Mirabolfathi, M.C.Perillo Isaac, W. Rau, B. Sadoulet, D.N.Seitz, B. Serfass, G. Smith, A. Spadafora, K. Sundqvist • University of California, Santa Barbara • R. Bunker, S. Burke, D.O. Caldwell, D. Callahan, R.Ferril, D. Hale, S. Kyre, R. Mahapatra, J.May, H. Nelson, R. Nelson, J. Sander, C.Savage, S.Yellin • University of Florida • L. Baudis, S. Leclerq • University of Minnesota • J. Beaty, P. Cushman, L. Duong, A. Reisetter Cryogenic Dark Matter Search Penn State Colloquium

  32. Nuclear Recoil bad at making Ionization Holes e- Germanium more ionization! Need a second, `fair’ measure of deposited energy… sound!  0 Both deposit, say, 20 keV Penn State Colloquium

  33. Our Detectors `Phonon sensor (4)’ (TES) Array of Transition Edge Sensors Ionization Electrodes (2) x-y-z imaging: from timing, sharing Z-coordinate, Ionization, Phonons ZIP Operate at 0.050 Kelvin Penn State Colloquium

  34. quasiparticle trap Al W Transition-Edge Sensor (TES) Al Collector quasiparticle diffusion ~ 10mK Cooper Pair RTES () 4 3 Ge or Si phonons 2 1 normal T (mK) Tc ~ 80mK superconducting The Phonon Sensor R. Schnee Penn State Colloquium

  35. Pulses 20 KeV Phonon (4) Charge (2) 0 300 0 300 Time (s) Time (s) 30 -30 -30 30 -30 30 Penn State Colloquium

  36. Separation of the types of recoils (electron recoils) Neutrons cause nuclear recoils too! Another background… (nuclear recoils) Sound Penn State Colloquium

  37. SUF Run 21 Germanium – Low Threshold 1.3 keV x-ray, L-shell Capture Shallow Site Neutron Background 10.4 keV Ga x-rays from 71Ge K-shell Capture R. Bunker Penn State Colloquium

  38. Background Neutrons from Cosmic Ray Muons Limited our earlier results…moved to a deep mine Penn State Colloquium

  39. Go Deep Underground to Evade Muons Penn State Colloquium

  40. Deep Facility Soudan Mine Hosts: State of Minn., U Minn., Fermilab 690 meters underground 2090 meters water equivalent Penn State Colloquium

  41. DAQ/Electronics RF-shielded Soudan II Clean room HVAC Mezzanine Mezzanine Front-end Electronics MINOS connecting tunnel Mechanical Detector Prep Shield Pumps, Clean Benches Icebox Fridge Cryogenics Down deep in the Soudan mine Penn State Colloquium

  42. Outside In lead plastic scintillators outer polyethylene ancient lead inner polyethylene Penn State Colloquium

  43. FET cards 4 K 0.6 K 0.06 K 0.04 K SQUID cards ZIP 1 (Ge) ZIP 2 (Ge) ZIP 3 (Ge) ZIP 4 (Si) ZIP 5 (Ge) ZIP 6 (Si) 14C 14C 14C A Cold Heart Results from first… poorer resolution Two `towers’ 6 detectors… 10 cm 4 Germanium (0.25 kg each), 2 Silicon (0.1 kg each) Penn State Colloquium

  44.  Calibration (133Barium) (e recoils) Phonons Ionization L. Baudis Energy, KeV Penn State Colloquium

  45. Better Source, Calibration Ionization Phonons Penn State Colloquium

  46. n Calib. (252Californium) (nuclear recoils) Reconstructed recoil energy, KeV S. Kamat Penn State Colloquium

  47. Tower 1 Soudan Data First Run • 92 calendar days • 53 live days, 1 kg Germanium Second Run • 140 calendar days • 74 live days, 1.5 kg Germanium 0.6 kg Silicon • Double `Exposure’ Penn State Colloquium

  48. Backgrounds often do FET cards 4 K 0.6 K 0.06 K 0.04 K WIMPs don’t scatter twice SQUID cards ZIP 1 (Ge) ZIP 2 (Ge) ZIP 3 (Ge) ZIP 4 (Si) ZIP 5 (Ge) ZIP 6 (Si) n,  0 14C 14C 14C Reject Multiple Interactions Penn State Colloquium

  49. 10.4 keV Gallium line Nuclear Recoils induced by a neutron source First Run After timing cuts, which reject external electrons Prior to timing cuts External e (address with timing cuts) B. Cabrera Penn State Colloquium

  50. Electrode Implants z  E `ZIP’ : `reconstruct’ z with start time, risetime External e : surface events, ionization missed External e  decay contamination, escaping compton recoils Ionization not collected Germanium Penn State Colloquium

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