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Astro-Particle Physics 2 Detectors

Astro-Particle Physics 2 Detectors. Manfred Jeitler. WS 2012/13. various types of interaction of particles and matter. charged particles ionisation inelastic scattering on electrons in solids: electron-hole creation excitation scattering on nuclei nuclear reactions

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Astro-Particle Physics 2 Detectors

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  1. Astro-Particle Physics 2 Detectors Manfred Jeitler WS 2012/13

  2. various types of interactionof particles and matter • charged particles • ionisation • inelastic scattering on electrons • in solids: electron-hole creation • excitation • scattering on nuclei • nuclear reactions • also for neutrons • Cherenkov and transition radiation • bremsstrahlung • practically only for electrons and positrons • photons: • photoelectric effect • Compton scattering • pair formation

  3. types of detectors • photographic emulsions • scintillators • ionisation detectors • gas detectors • ionisation in liquids • semiconductor detectors • cloud and bubble chambers • Cherenkov and transition radiation detectors

  4. Bethe-Bloch equation

  5. particle entrance window high voltage RHV >> RA amplifier ground Geiger-Müller counter wire

  6. Cloud Chamber positron

  7. Cloud Chamber

  8. Bubble Chamber

  9. Photographic emulsion OPERA experiment

  10. scintillators • simple • fast • still used today scintillator light guides

  11. photon interaction • in matter: • photoelectric effect • Compton effect • pair production

  12. shower

  13. semiconductor detectors

  14. Cherenkov radiation in a pool-type reactor

  15. shock wave behind supersonic plane (Prandtl-Glauert effect)

  16. the Superkamiokande neutrino detector (Japan)

  17. principle of the Cherenkov effect

  18. compared to water (and some other media), in air the Cherenkov effect: • appears at much higher velocities • shows a much smaller angle • produces far fewer photons

  19. A typical large particle detector on a colliding-beam accelerator: CMS (Compact Muon Solenoid) CMS

  20. Space Experiment Constraints • Space qualified parts • High cost/performance: $250k/0.8GHz computer, $4k/2kFF FPGA • Longer lead time (12–26 weeks) for delivery • You can qualify parts by yourself after a lot of work: eg custom ASIC • Do not believe vendors just because of NASA qualification • NASA qualification: screening, traceable records • Low Power • Custom ASIC, low clock speed • Redundancy • Configuration updates • Takes a week to go through normal approval process • Fast-track change still could be an order of day • These are not all

  21. The Alpha Magnetic Spectrometer (AMS) on the International Space Station (ISS)

  22. Energy loss in individual processes in detectors • to achieve good energy resolution, many individual processes must take place • Poisson statistics (fluctuation = sqare root of the number of events) • most astroparticles may have much higher energy but leave only a tiny part of it in detector • energy needed per process: • ionization 30 eV • scintillation 25-100 eV (depending on material) • electron-hole pair (solid state) 3 eV • break-up of Cooper pair (cryogenic superconductors) 1 meV

  23. Long Wavelengths Require Low Temperatures Hoffman et al, Proc of SPIE Vol 5167 near infrared mid infrared far infrared

  24. Infrared Telescopes must be cooled in Space Mid infrared Far infrared sub-mm T Nagakawa 19th International Symposium on Space Terahertz Technology, Groningen, 28-30 April 2008 Telescope radiation (10% emissivity) Telescopes as cold as around 5 K are required to achieve natural background-limited observations in the mid- and far-infrared

  25. T > 40 K Radiative cooling Space is a 3K heat sink 1 k < T < 40 K Liquid He Solid Hydrogen T < 1 K 3He, 4He Sorption coolers T < 100 mK Dilution Refrigerator (in 0 g !) Adiabatic Demagnetization Refrigerator Cryogenics in Space is Hard …but needed for background limited performance B Collaudin and N Rando, “Cyogenics 40 (200) 797” Mechanical Coolers Longer lifetime Less weight Less power improvement

  26. Liquid He II (170 l or 25 kg) superfluid loaded at launch time Mechanical coolers extended Helium life by 360 days! After He is depleted mechanical coolers can still cool down to 30 K Mechanical Coolers in Operation (AKARI) Mechanical coolers shield cryogen from higher heat fluxes M Hirabayashi et al, Cryogenics 48 (2008) 189–197 From Aug 2006 until May 2007 AKARI completed the far-infrared All-Sky Survey covering about 94 per cent of the entire sky Cryogen ran out after that

  27. Mechanical Coolers: Longer Missions, Larger Telescopes AKARI 0.7 m mirror diameter Cryo operations 15 months SPICA 35 m mirror diameter Cryo operations 5 yrs 2006 ~2018 H Matsuhara SPICAT Nakagawa et al / Advances in Space Research 34 (2004) 645–650

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