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A.K. DRUKIER TEL: [ 703 225 8654 ] adrukier@gmail

A.K. DRUKIER TEL: [ 703 225 8654 ] adrukier@gmail.com August 2014 Nano-Booms => Dark Matter => Neutrino Geology.

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A.K. DRUKIER TEL: [ 703 225 8654 ] adrukier@gmail

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  1. A.K. DRUKIER TEL: [ 703 225 8654 ] adrukier@gmail.com August 2014 Nano-Booms => Dark Matter => Neutrino Geology

  2. What we needNew class of detectors for neutral particles:Neutrons, Neutrinos, Dark Matter candidates (WIMPs)Neutrons => Homeland Security, Neutron Microscopy Neutrinos => Fermi Lab, Neutrino GeologyDark Matter => Low mass WIMPS ( < 10 GeV/c2). Very high Mass WIMPs ( > 400 GeV/c2) Spin dependent interactions (Li, F, Al) New SIGNATURES

  3. AKD/LS, SG/ EW, AKD/DF/DS, F.T. Avignone et al. “25 Years Later” Classical (NaI) detectors (!!! DAMA!!!) Good news: high mass, low A, annual modulation Bad news: high threshold Ultra-pure Ge-detectors Good news: best background Bad news: low mass, mediocre threshold (improved in CoGeNT) Cryogenic bolometers Good news: works, good threshold for heat Bad news: background? bad threshold for ionization Liquid Xe Good News: Great Mass, High A Bad news: Mediocre S1 threshold => MDM > 12.5 GeV/c2

  4. Signatures • 1) N2 dependence on cross-section; 2) Range of recoiling nuclei is below 100 nm; 3) Particular ratio of FM = (TED/ETE) TED = Total energy deposited; ETE = Energy transferred to electrons; 4) Annual modulation effect (AME) , Diurnal Modulation Effect (DME), Other directional effects.

  5. “25 Years Later” Four detectors seems to see WIMPs, but MWIMP < O(10 GeV/c2) Due to Kinematics Exclusions are : • Liquid Xe only for MWIMP > 15 GeV/c2 • CDMS-Ge only for MWIMP > 10 GeV/c2. • S1 in L. Xe small => Eth (S1) = O(10 keV) Ionization in Ge low => Eth(ionization)= O(5 keV)

  6. “25 Years Later” DAMA, CoGeNT, CDMS-Si, CRESST, CDMS-Ge, L.Xe AGREE, only if • MODEL 1 => 4.1 < MWIMP < 6.8 GeV/c2 • MODEL 2 => 3.6 < MWIMP < 5.8 GeV/c2. This may suggest Assymetric DM a la S. Nussinov, 1985

  7. The “normal “ presentation

  8. KINETICS • The maximum mass transferred by a WIMP to nucleus depends on • WIMPs speed (v), nucleus mass (Mn) and WIMP mass (MDM) by • Emax = 2m2v2/Mn • wherein reduced mass m is • m = Mn x MDM/(Mn + MDM) • MDM >> Mn => Emax => 2 MnV2, i.e. independent of the MDM. and • optimal fit Mn = MDM => Emax => ½ MDMV2

  9. Challenges 1) For MDM < 10 GeV/c2 No good detectors exist 2) For 10 < MDM < 20 GeV/c2 Contradictory results => Low S/B 3) For 20 < MDM < 300 GeV/c2 CDMS-Ge,LUX and Xenon negative 4) For MDM > 300 GeV/c2 Need 10 ton , A > 70, AME

  10. ZOO of DETECTORS– Part I Ordered by minimal velocity at MW = 10 GeV/c2 (1) F-thermites (2) Nano-explosives (3) O-thermites (4) Be-ssDNA (5) Enzymatic (6) Be-SSC (7) PICASSO (8) DAMA (9) CoGeNT (10) CDMS-Si (11) CRESST (12) CDMS-Ge (13) SIMPLE (14) L. Xenon (15) COUP

  11. ZOO of DETECTORS – Part II Ordered by Atomic Number A(Be) =3- 9 Thermites,Be-ssDNA , Be-SSC A(N) = 14 Nano-Booms A(O) = 16 Enzymatic, CRESST A(F) = 19 F-thermites, PICASSO, SIMPLE, COUP A(Na) = 23 DAMA A(Si) = 28 CDMS-Si A(Ge) = 73 CoGeNT, CDMS-Ge A(Xe) = 128 l. Xenon A( I) = 131 DAMA A(W) = 173-200 Au-ssDNA, Nano-booms, CRESST

  12. ZOO of DETECTORS– Part III Ordered by Eth Eth < 0.5 keV Thermites, Nano-explosives, 0.5 < Eth < 1 keV Be-ssDNA, Enzymatic, Be-SSC 2.0 < Eth < 3 keV CoGeNT, PICASSO Eth = O(3.5 keV) DAMA Eth = O(5.0 keV) CDMS (Si and Ge) Eth = O(6.5 keV) l. Xenon Eth = O(7.0 keV) CRESST Eth = O(15 keV) COUP

  13. Three Models of DM Halo

  14. “ - CRESST- OLD

  15. Vcritical of Existing and “Gedanken” Detectors -II

  16. Vcritical for New\Old Detectors

  17. Vcritical for New/Old Detectors

  18. Figure of Merit forNew/Old Detectors

  19. Annual Modulation Effect

  20. Precision WIMPology I

  21. Low Mass WIMP’s Detection Challenge Kinematics requires low mass targets ergo cross-section is very low ( smaller effect of coherent scattering) and requires large mass. Ethreshold must be very low ( < 0.5 keV) => current methods of background rejection does not work => best spatial resolution is must to improve S/B ratio => importance of directionality to detect AME and DM NEED A NEW CLASS OF DETECTORS I

  22. Superheated Detectors • Bubble Chambers, Cloud Chambers – dx = O(1 mm) • Superconducting Granular detector – dx = O(10 microns) • Magnetic Nanotechnology detectors – dx = O(100 nm) • Explosive Nano-droplets detectors -- dx = O(5 nm) One component-high explosives • Two components — Thermites • Biological Detectors • I) DNA-based detectors; • II) Enzymatic processes based detectors

  23. Advantages of “New” Detectors1. Room Temperature;2. Low Cost and potentially very high mass;3. Low mass targets (Li, Be, B, C, N, O, F) possible;4. Very high mass targets ( A > 175) possible;5. Very low Energy threshold ( 0.1-0.5 keV);6. New methods of background rejection;7. Directionality.MADE POSSIBLE BY NANOTECHNOLOGY

  24. Properties of New Detectors TYPE Mass Eth [keV] Directionality. Be-SSC O(50 kg) 0.5-1.0 No Be-ssDNA O(100 kg) 0.3-0.6 YES Enzymatic O( 1 T) O(0.5 keV) No Explosives O( 50 T) O(0.2 keV) No O-Thermites O( 10 T) O(0.2 keV) YES F-Thermites O( 50 T) O(0.1 keV) YES I

  25. Nano-BolometryEnergy LossesdE/dX = Ax Z1xZ2 /[ (Z1)0.666 + Z20.666)]2RangesMuons= O( m), Electrons =O( mm ), Alphas = O(50 microns), Recoil = O( 5 nm)Specific Heat:Cv = a(T/TDebay)3 + bT => O(10-5 keV/nm3)s

  26. Energy StoredEnergy Stored ≈ VgrainHigh Explosives => 3.5-4.5 kev/(nm)3O-Thermites => 3.0-4.0 keV/(nm)3F-Thermites => 2.5-3.5 keV/(nm)3Enzymatic => 1.5-2.5 keV/(nm)3Amplification = Estored/Edeposited => 100-1,000

  27. Nano-Explosives Detectors(Nano-Booms) • Use very low mass targets – Li, Be, B, C, N, O • Large choice of compounds to select from; • Each explosives grain is “independent” bolometer; • Amplification of signal from 0.1 keV to 1 MeV possible; • dE/dx (nuclei) >> dE/dx (electrons) => excellent background rejection; • Room temperature detectors ,F

  28. Other Advantages * Use modern nano-technology => nano-size droplets of explosives * High energy content => large signal amplification => Gain 1,000/grain * Packaging 1,000s of grains in 500 nm balls => Gain 1,000/ball * May use modern acoustics to detect/localize nano-booms * May use low cost IR-cameras • Used materials have reasonable Debay Temperature  TOTAL GAIN = 106 Limits on “thermodynamic description” : • Works when number of molecules > 100, ergo R > 1 nm • Dynamic description may lead to factor 2 difference.

  29. Properties of “nano-booms” detectors Eth is proportional to grain volume, and R=O( 5 nm) grains can be produced efficiently; Energy stored is O(4 keV/(nm)3), signal is changing as R 3, ergo 5 nm grains gives > 1 MeV; Random distribution of grains in colloid does not increased transition width; Millions of tons of nano-explosives are, alas, produced each year; One can select parameters of detector, so-that explosion of a single nano-grain: * does not trigger other grains; * triggers other grains, with Ngrains(triggered) = 100-1,000.

  30. Characteristics of “nano-boom” detectors • Two main sub-classe: Explosives and Thermites • Three levels of ignition temperature: [Low = O( 50 oC)], normal [O ( 250 oC)], high [O(1,000 oC)] • Any combination of explosives possible; • Complementary properties of explosives and thermites. • Behaviour of micro-granular explosives well understood, • Nano-explosives partially understood; • Propagation and damping of explosion well-understood; • Explosives are not detectors, there are transducers; • Many methods to detect the explosions can be implemented ( accoustic, Optical). Nunc Hercules contra plures: Cryogenic Detectors < 20 scientists/year in last 20 years Explosives 10,000 scientists/year in last 50 years

  31. Properties of Explosives • Low Z explosives (mostly organics and nitrides)) PETN = C(CH2)ONO )4 d = 1.6 g/cc Tignition = O(250 oC) RDX = (CH2)3N3(NO2)3 d= 1.65 g/cc Tignition = O(250 oC) TNT = C6H2CH3(NO2)3 d= 1.55 g/cc Tignition = O(200 oC) • Medium Z explosives (mostly azides) Nitrogen iodide N4I3H3 d= O(2 g/cc) Tignition = 30 oC CD-azide Cd (N3)2 d= O(1.5 g/cc) Tignition = 30 oC Cu-Azide Cu(N3)2 d=O(1.5 g/cc) Tignition = 20 oC • High Z explosives (mostly Pb, also Hg fulminate and compounds of gold) Pb-styphate C6H(NO2)3(OPb) d= 3.1 g/cc Tignition = O ( 200 oC) Pb-azide Pb(N3)2 d= 3.8 g/cc Tignition = O(150 oC) PbO6 PBO6 + dextrine(7%) d= 3.7 g/cc Tignition = O(150 oC)

  32. Simple Implementation using H2O2 • 70% ( H2O2) = 30%( Boron) is a good explosive • Implementation 1: Toperation = -1 oC, naked B-grains WIMP interacts with Oxygen • => recoiling nuclei heats/melts H2O2 ice • => liquid H2O2 burns Boron • Implementation 2: Toperation = RT, coated B-grains WIMP interacts with Boron • => recoiling nuclei heats grain and melts plastic • => liquid H2O2 burns Boron

  33. Properties of O- Thermites Well known examples Al2 + (Fe2O3) => Al2O3 + 2 Fe + 851.5 kJ/mole Al2 + (WO3) => Al2O3 + W + 832.0 kJ/mole Both these reactions have Tignition > 1,000 oC. For good O- Thermite reaction: Metal 1 should be very active and Metal 2 much less active. 4 Li + OsO4 => 2Li2O + Os => 500 kJ/mole This reaction have Tignition = O(40 oC) but Os is costly

  34. Advantages of F-Thermites We can replace oxides by hexa –fluorides 6Li + WF6 => 6 LiF + W + energy (Li, W) 6Na + WF6 => 6NaF + W + energy (Na, W) 6K + WF6 => 6K + W + energy (K, W) Energy from reaction of fuoride is 20-30% smaller than by oxides . But !!!!!!!! Metal Fluoride Tm( oC) Tb(oC) (Tb-Tm)(oC) V VF5 18.0 > 100 > 100 Mo MoF6 17.5 37. 19.5 W WF6 2.5 17.5 15 Re ` ReF6 18.8 47.6 28.8 Os OsF6 32.1 45.9 13.8 Ir IrF6 44.4 53. 8.6 Pt PtF6 61.3 69.14 7.8 For hexa-fluorides Tb = O(40 oC) and Tignition = O(Tb)

  35. Electrons can not ignite thermite Electrons/gammas are main source of background in all current WIMPs detectors. Per g/cm2 , the energy deposed by recoiling nuclei with charge Z1 in medium including heavy metal Z2 is proportional to Z1* Z2/ F(Z1,Z2). . In classical detectors, active voxel is about 50 microns and range of recoiling nuclei is about below 50 nm. Signal due to recoiling nuclei is comparable with signal from typical background electrons ; In detector with active size of O ( 5 nm), the energy deposed by electrons is about 5,000 fold smaller. This leads to dE/dX (electrons) = O( 1 ev/nm ) => dT = 0.01 oC, which is not sufficient to ignite thermite. The probability of ignition is P = exp(-dTignition/0.05 oK) = exp( -100). Thus thermal instabilities are totally negligible even if we have trillions of grains in detector.

  36. Signal Calculation • Lets calculate the signal for R= 5 nm +> V = 500 nm3. Vetex grain flips , and produces about 4 keV/(nm)3 x 500 = 2 MeV. • The heat escapes into a Rball = 100 nm => n =1,000 grains, ergo there is propagation of ignition radially from vertex grain => 1,000 grains flips . • This gives energy deposition of Etotal = 1,000 x 2 MeV = 2 GeV. • We can assume that the ignition of each grain by a recoiling energy will lead to flipping about 100-1,000 grains by thermal effects and presence of “debris” of exploding grain; • It is theoretically possible, that we can detect the direction of recoiling nuclei by the asymmetry of acoustic signal in a few pick-up loops built into “acoustic gradiometer”. This however, will require some experiments.

  37. “Explosive diode” for low Mass WIMP` The mixture of spherical grains is “symmetric”. Evaporated structures permits directionality • Xx Xx • Xx Xx • Xx Xx • Xx Xx • ==>XxXx <== [Ga, WF6]] • Xx Xx • Xx Xx • Xx Xx • X low A (F) x = high A (Ga) • High energy transferLow energy transfer • Asymmetry is due to mismatch of target and WIMP mass, i.e. is kinematics dependent

  38. Explosives/

  39. Challenges of nan-boom Detectors • C14 will be a background – ad ovo synthesis need to use carbon from 1 mln years old petroleum; • Need to well control” stochimetry; • Control of size important but not crucial; • To diminish fast neutrons / Cosmic Rays => underground • Efficient “nano-explosion detection” (acustic, optical) must be developed. Backgrounds, backgrounds, backgrounds… but • It’s a new class of “room temperature” detectors; • They have the high mass and low threshold; • It’s “elegant”; • Nunc Hercules contra plures.

  40. Acknowlegments We acknowlege discussions with: • F.T. Avignone, R. Bielsky, R. Fagaly, K. Freese, • C. Kurdak, A. Lopez, G. Tarle, D. Spergel. Ad memoria Ron Brodzinsky and Roman Juszkiewicz

  41. 1) Neutrino Geophysics vs. Neutrino Geology ; 2) Reverse beta decay => Stationary Detectors => N. Geophysics; 3) Coherent Scattering => Mobile Detectors => N. Geology: Solar Neutrino background : pp => 1010v /(cm2xsec), low energy pep, Be7 => 109 v/(cm2x sec), Ev = O(1 MeV); !!! B8 => 108 v/(cm2x sec), high energy !!! • For average density Xi of K, Th, U => S/B = O(1) • => too low for cold spot emission tomography • With nano-boom detectors, directionality => S/B > 10 • => even cold spot emission tomography is possible. In reality S/B =100-500, 5 ton detector = 100 events/month

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