1 / 42

Instrumentation for Astroparticle Physics

Instrumentation for Astroparticle Physics. W. Hofmann MPI für Kernphysik Heidelberg. . Dark matter. . Neutrinos (MeV: sun, SN GeV: atmosphere PeV: CR accerators). Mono- poles. Axions. . Cosmic ray particles -> 10 20 eV. Grav. waves. Electromagnetic radiation -> 100 TeV.

pravat
Download Presentation

Instrumentation for Astroparticle Physics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Instrumentation forAstroparticle Physics W. Hofmann MPI für Kernphysik Heidelberg

  2. Dark matter  Neutrinos (MeV: sun, SN GeV: atmosphere PeV: CR accerators) Mono- poles Axions  Cosmic ray particles -> 1020 eV Grav. waves Electromagnetic radiation -> 100 TeV 

  3. Peak detected flux Detection threshold Optical 100000000 1000000 10000 Radio 100 X-Ray IR Energy [eV] 1 UV Neutrinos (?) Gamma Angular resolution [degr.] Neutrinos 100 Gamma 10-2 X-Ray Optical 10-4 10-6 10-6 100 100 106 106 1012 1012 Radio Energy [eV] 10-6 State of the field: a charming infant Astrophysics with gamma rays and neutrinos Flux sensitivity Number of sources Angular resolution

  4. Gamma rays and cosmic rays Cosmic ray particles -> 1020 eV Electromagnetic radiation -> 100 TeV 

  5. The big issues in cosmic-ray physics • at low (GeV – TeV) energy: • antiparticles in cosmic rays? • AMS • at medium (PeV) energy • elementalcomposition, change in • composition at knee? • (KASKADE,…) • at high (EeV) energy • spectrum, particles beyond • GKZ cutoff? • AUGER eV • Sources of cosmic rays • traced in the light of • (secondary) gamma rays • g-yield = CR density x target density EGRET ~ 100 MeV

  6. Horizon due to gg inter- actions Propagation of electromagnetic radiation In the Earth’s atmosphere Ultraviolet Radio Gamma ray X-Ray Infrared Visible In space 500 km 100 km Air shower Fluorescence light Radio waves Cherenkov light Particles at ground level 10 km Sea level similar effect: Cosmic-ray propagation cuts off at 1020 eV

  7. GeV/TeV CR: Alpha Magnetic Spectrometer AMS-01 (1998) AMS-02 on ISS

  8. GLAST:g-rays in the GeV energy range

  9. VHE air shower detectors: Cherenkov telescopes Effective detection area: ~ 50000 m2 ~ 120 m Image of the shower in the PMT camera ~ 1o Cherenkov-Light Image Orientation shower direction Intensity energy of primary Shape type of primary 100 photons/m2 TeV within a few ns ~ 120 m

  10. Telling g-rays from hadronic cosmic rays z z p g g (?) x p (?) x y y x x

  11. The imaging atmospheric Cherenkov technique Pioneered by the WHIPPLE group Perfectioned in CAT telescope Stereoscopy with HEGRA WHIPPLE 490 PMT camera

  12. Four eyes see better than one: H.E.S.S.(and VERITAS, CANGAROO, …) • 12 m Cherenkov telescopes • under construction in Namibia • Combine • Stereoscopy from HEGRA telescopes • improved angular resolution • enhanced background suppression • Trigger and fine pixels from CAT telescopes • Monitoring from Durham telescopes • 100 m2 mirror • 15 m focal length • 960 PMT camera • 1 GHz analog pipeline • 50 GeV threshold • 10 times improved • sensitivity cf. HEGRA

  13. Source hunting with MAGIC • 17 m dish, 220 m2 active mirror • low weight  fast positioning • high-speed optics and electronics • initial PMT camera • later GaAsP and APD detectors •  10 GeV threshold Aluminum mirrors PMT with hemispherical window and optical signal transmission

  14. Sensitivity and limitations of the technique • Angular resolution, • cosmic-ray rejection limited by • Shower fluctuations • Earth magnetic field • Also, light yield depends on height! Angular resolution for “ideal” detector Side view of shower • Irreducible background • Cosmic-ray electrons • can only be discriminated on the basis of shower direction. Hard to go beyond mCrab sensitivities with the imaging Cherenkov technique …

  15. Better vision – novel photon detectors e ~ 62% e ~ 22% e ~ 15% • Hybrid PMTs • GaAsP limited to few 100 mm2 • Si (APD) even smaller, QE below CCD • Better photon detectors • for Cherenkov telescopes • allow large savings • improve performance • need m2 cathode area …

  16. An alternative approach: non-imaging detectors STACEE CELESTE secondary reflector and PMTs Large mirror area and hence low energy threshold Poor cosmic-ray rejection Significant learning curve CELESTE sees Crab at 50 GeV Competitive in the long run?

  17. Tail catchers: particle detectors Tibet air shower array (Scintillators) Milagro, Los Alamos (Water Cherenkov) • High altitude and • large area coverage • Avantages • large solid angle • 100% duty cyle • Disadvantages • TeV+ threshold • marginal (Crab-level) sensitivity • Complementary to Cherenkov telescopes ARGO,Tibet (RPC array) planned

  18. The ultimate experience: AUGER • Air shower detector • 3000 km2 area • two detector technologies • particle detectors • fluorescence telescopes • ~ 20000 events> 1019 eV • ~ 100 events> 1020 eV 1600 detectors 1.5 km spacing

  19. AUGER fluorescence detectors

  20. AUGER performance Detection area Simulated spectrum

  21. The view from above: OWL CR n Threshold: 1019-1020 eV Eff. area: few 106 km2sr 106 pixel focal plane flat panel PMTs ? > 50o field of view

  22. Neutrinos (MeV: sun, SN GeV: atmosphere PeV: CR accerators) 

  23. High-Energy Neutrino Astrophysics • Proton accelerators • generate roughly equal numbers • of gamma rays and neutrinos ! • Neutrinos are not absorbed in • sources; they escape even from • strong sources • Neutrinos do not interact • during propagation Background: atmospheric neutrinos Signal from cosmic accelerators

  24. Scientific American • Extreme Engineering Issue • Seven wonders of modern astronomy • The sharpest • The biggest • The farthest flung • The most extensive • The swiftest • The deadliest • The weirdest: • AMANDA at the south pole 4 strings 10 strings AMANDA II (2000) 19 strings, eff. area ~ 5x104 m2

  25. Detection: Cherenkov light in water / ice ICE CUBE, ANTARES: 1000000000 m3 ~ 5000 PMTs Threshold ~ 1 TeV 1 km deep under water / ice m Key difference: Ice / AMANDA II: ~ 100 m absorption length, ~ 20 m scattering length  diffusive component  angular resolution 1.2o Water / ANTARES, NESTOR ~ 60 m absorption length, ~ 200 m scattering length  angular resolution 0.2o n

  26. Instrument R&D ANTARES Demonstrator • Optical module design • Deployment schemes • PMTs • Signal transmission • Digital modules ARS 1 GHz analog ring sampler ASIC with digital signal procession (ANTARES) Module with optical signal transmission (AMANDA)

  27. AMANDA at the South Pole n-Sky (AMANDA ’97)

  28. ICECUBE • 80 “Strings” of 60 PMTs • in 1400 – 2300 m depth • Physics issues (ICECUBE, ANTARES, NESTOR): • neutrinos from CR accelerators • neutrinos from DM annihilation • atmospheric neutrinos, oscillations • magnetic monopoles • galactic supernovae • …

  29. n Solar neutrinos Super-Kamiokande: the neutrino image of the sun

  30. Detectors for solar (MeV) neutrinos BOREXINO, KAMLAND(2): Liquid Scintillator SNO: Heavy- Water Cherenkov LENS: Liquid Scintillator with “Tag” SuperKamiokande WaterCherenkov pp n Be pep ne e ne n e n n n Lu* g Yb p p e e e D e 50 ns n-flavor no (NC)yes (CC)no (NC)yes (CC) n-energy res. poorgoodpoorgood threshold 4-5 MeV4-5 MeV1 MeV0.3 MeV

  31. Alternative techniques ICARUS: liquid argon DC HERON: superfluid He; evaporation by photons/rotons and scintillation air shower HELLAZ: TPC delta-ray

  32. Darkmatter 

  33. The dark side of the universe • CMB (Boomerang, Maxima) • High-z Supernovae, BBN • ~ 1.0 • M ~ 0.2-0.3 • B ~ 0.03 – 0.05  most matter is dark, nonbaryonic Particle physics candidates, e.g. WIMPs, accumulate in the halo of galaxies (local density 0.3 GeV/cm3)

  34. Searching for WIMPs Principle: elastic scattering on nuclei Typ. recoil: a few 100 eV / GeV WIMP mass Typ. rate: a few events / kg / day WIMP Signature: 7% annual modulation Dark matter halo <v>  300 km/s Peak velocity June 2nd v  30 km/s Earth Phonons Light Recoil Sun WIMP Ionization Galactic centre Cu v  230 km/s Pb

  35. +3% Deviation from average rate, 2 – 6 keV 0 -3% The classical approach: DAMA 9 NaI dectors, total ~100 kg Threshold ca. 1-2 keV (equiv. Energy) Background ca. 1.5-2 /kg keV Day Similar: UKDMC, … Significance of modulation: 4 s near threshold rate saturated by dark matter!

  36. Mind over matter: cryogenic detectors Ionisation Phonons CDMS (Si, Ge) Thermometer: superconducting film near transition (20 mk); Ionisation (and Edelweiss, …) Light Phononen CRESST (CaWO4) Thermometer: superconducting film (15 mK) Detection of light using absorber with thermometer Phonons

  37. Reach of cryogenic detectors Romani et al. Spectroscopy of single photons from the Crab pulsar Transition edge sensor coupled to W detector (18m x 18m x 40 nm) DE < 0.15 eV Challenges: Size Resolution Speed (usually limited to kHz)

  38. CDMS vs. DAMA … and the future R. Gaitskill, V. Mandic http://cdms.berkeley.edu/limitplots/ DAMA 58000 kg-days 3800 m water equiv. CDMS: 11 kg-days 16 m water equiv. CDMS Soudan GENIUS Heidelberg-Moskau DAMA (3 s) CDMS CDMS Stanford CRESST CDMS Soudan GENIUS

  39. GENIUS: the simpler the better ? Germanium detectors (100 kg) supended in ultra-pure liquid nitrogen ~ 12 m Test facility under construction at LNGS

  40. Bubble chamber revival: Picasso Rate dE/dx threshold adjusted by detector temperature 20o C 15o C 10o C The Picasso detectors: superheated droplets in a polymerized gel. Detection via noise (piezo transducer) En First results – not yet competitive, but in the right ballpark

  41. Astroparticle Physics • a fascinating application of • particle physics instrumentation • to new questions • numerous interesting and • challenging developments, both • in physics and instrumentation • impossible to do • the field justice • in 45 min. !

More Related