Development of New Photosensors for Huge Detectors

Transcription

1 Development of New Photosensors for Huge Detectors Daniel Ferenc Physics Department, University of California Davis Work supported by National Nuclear Security Administration (NNSA), Office of Nonproliferation Research and Engineering, DOE

2 Very rare and/or weak phenomena - Proton Decay - Neutrino Physics - Geo-neutrino Physics - Neutrino Astrophysics - Gamma-ray Astronomy (low detection threshold + wide acceptance angle) - Ultra-high energy cosmic rays (>10 19 ev) - Neutrinoless Double Beta Decay - WIMP Searches

3 Sensitivity for the detection of very rare phenomena Very Large Volumes/Areas No No other other choice choice than than Natural Transparent Media (Water, Atmosphere, Ice, +GdCl, scint.) PHOTOSENSORS

4 The Unbeatable Reality of Mr. Liouville Cherenkov angle in water ~40 degrees Full angular coverage Camera surrounds the detector volume

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6 Irreducibly Large Illuminated Area strong internal signal concentration from the photocathode to the dynode column Vacuum ( photon photoelectron )

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8 Announcement of Awards for Developing Conceptual Designs for a Deep Underground Science and Engineering Laboratory (DUSEL) July 21, 2005 From a very strong field, the Homestake Mine (SD), and the Henderson Mine (CO) stood out as by far the most promising prospects for further consideration. The conceptual designs the teams associated with these sites will develop will lead to more detailed plans associated with a down-select to a single site in the third stage of the community-based planning process.

9 Large water projects in Colorado ~75 million years ago

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11 CERN ~250 million years ago

12 Frejus (near CERN) - MEMPHIS TRE

13 Hyper-Kamiokande DUE

14 OUR GOAL To introduce a new Technology for Industrial Mass-Production of large photosensor areas based on modified existing technologies (e.g. the assembly of modern, plasma and field-emission flat-panel TV screens; low production cost ~$1000 per sq. meter) + REAL (non-physics) MARKETS

15 SEARCHING FOR RARE AND/OR WEAK RADIATION SOURCES PARTICLE ASTROPHYSICS (new generation of experiments) MEDICAL IMAGING WIDELY ACCESSIBLE MEDICAL DIAGNOSTICS Industrial Mass-Production of Very-large-area cameras NUCLEAR SECURITY (nonproliferation)

16 GOOD MARKETS for MASS PRDUCTION? PARTICLE ASTROPHYSICS (new generation of experiments) MEDICAL IMAGING WIDELY ACCESSIBLE MEDICAL DIAGNOSTICS Industrial Mass-Production of Very-large-area cameras NUCLEAR SECURITY (nonproliferation) REAL MARKETS (STEADY and LARGE)

17 If you have a good idea today, you are likely to require many committees, many years and many people to get the project from concept to observation. The situation was very different in 1964 Neither of us remember a formal proposal ever being written to a funding agency. Ray Davis Jr. and John Bahcall, CERN Courier July/August 2000

18 If you have a good idea today, you are likely to require many committees, many years and many people to get the project from concept to observation. The situation was very different in 1964 Neither of us remember a formal proposal ever being written to a funding agency. Ray Davis Jr. and John Bahcall, CERN Courier July/August 2000 OUR REALITY: 1. Invent a new technology 2. Patent protect 3. Get a grant 4. Find a real MARKET 5. Find venture capital 6. Form a startup company

19 Several Unconventional Photosensors UC Davis (D.F. and Eckart Lorenz) Flat-Panel ReFerence Camera Concept (Patented) Light Amplifier - general concept ReFerence panels scintillator (fiber) readout Hemispherical - QUASAR or SMART PMT in a modified configuration + Geiger-mode APDs SIMPLE Space Imaging Camera Concept for EUSO, OWL, but also ground-based applications (Patented) Weizmann Institute, Israel (Amos Breksin, Rachel Chechik) Gaseous panels CERN (Braem, Joram) More-classical HPDs

20 Semiconductor Photosensors developed very successfully (but pixel sizes and areas - too small) Vacuum Photosensors (suitable for large-area applications, strong area reduction) did not develop significantly since mid-1960s Why? Because of the Vacuum?

21 DYNODE COLUMN GLASS BULB

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24 Development of Other Vacuum Devices ~1960 ~2000 Production Cost 05 < $1,000/m 2

25 ENCLOSURE: FLAT-PANEL TV PHOTON ELECTRON CONVERSION: CLASSICAL PHOTOCATHODE 3 existing mass-production technologies ELECTRON DETECTION: SEMICONDUCTOR Geiger-MODE AVALANCHE DIODE

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27 Ideal Light Concentrator (takes the maximum of Liouville!) Photoelectrons Photon Photocath PIN, APD, or CINTILLATOR Optimal Electron Lens

28 Ideal Light Concentrator Very Important: Hexagonal Packing Entrance Aperture Photocathode Optimal Electron Lens

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30 Flat-Panel Honeycomb Sandwich Camera Construction Industrial Production (no glass blowing etc.) Intrinsic Mechanical Stability, Low Buoyancy,..

31 PROTOTYPE DEVELOPMENT UNSEALED 1-PIXEL SEALED PANELS (7 pixels, 5 inch) CYLINDRIC HEXAGONAL Equipment (Candescent, Litton Night Vision) ~$2M SEALED with In/Au/Cr SEALED with SOLDER GLASS

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33 Strong signal concentration, factor ~ 1500 (one of our goals) APD Replaces the entire Dynode Column! Provides ~100% Collection Efficiency! Scintillator + Fiber (both of small and comparable diameter good coupling efficiency)

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35 UHV Transfer System : Photocathode deposition Indium/Au/Cr deposition Vacuum sealing

36 The vacuum sealing process lid tube

37 Light Amplifier Concept Scintillators + fiber optics NO electronics in the vacuum READOUT APD array Resolution determined outside!!

38 Light Amplifier Concept Scintillators + fiber optics NO electronics in the vacuum READOUT APD array Resolution determined outside!!

39 SMART PMT, QUASAR

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41 SMART PMT, QUASAR Hemispherical LIGHT AMPLIFIER Fiber Plate Scintillator Y2SiO5(Ce) Al (100 nm) Geiger-mode APD array 1 photoelectron >15 photons in APD

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43 SMART PMT, QUASAR Pulsed LED+fiber CURRENT SETUP electron SINGLE Geiger-mode APD, 1x1 mm 2 No face-plate low light Collection Efficiency ~1:150

44 Pulsed LED+fiber Geiger-mode APD ZS-2 from Sadygov, MICRON Coax signal 57.4 V power EXTREMELY SIMPLE!

45 A Typical Single-Photon Signal in the Geiger-mode APD Amplitude Time 1 photo-electron 200 mv

46 Superposition of many light pulses in the Geiger-mode APD (full bandwidth) Amplitude Time Note the individual photon structure and decay spectrum of the scintillator

47 Rotating Light Source (LED) 30 cm Scintillator 1 cm Î IMAGING (even without fiber coupling)

48 Gaseuos Photomultipliers GPM A. Breskin et al. Weizmann Institute GEM- and THGEM-based gaseous photomultipliers

49 Semitransparent Photocathode Multi-GEM GPM Reflective Photocathode higher QE! A. Buzulutskov et al. NIM A 443 (2000)164 D. Mörmann et al. NIM A 478 (2002) 230 high 2D precision [ mm] high gain [>10 5 ] single photon sensitivity! fast signals [ns] good timing

50 GPM for visible light sealed 3 Kapton-GEMs & KCsSb PC Sealing in gas: In/Sn; C Sealed detector package with semitransparent K-Cs-Sb PC Q E % % = best QE measured after sealing. 2 weeks stability ~ QE in transmissive mode Ar /CH495/5% Wavelength [nm] Best sealed GPMT: stable for 1 month under development: Silicon (with Glasgow Univ.), ceramic Expected higher stability D. Mörmann et al. NIM A504 (2003) 93 M. Balcerzyk et al. IEEE TNS 50 (2003) 847

51 A VERY FLAT GASEOUS IMAGING PM ~10mm hν readout photocathode THGEM 100x100mm2 THGEM With 2D delay-line readout φ 0.3mm holes

52 CONCLUSIONS Photosensors are key element for many future projects New low-cost photosensors produced in large quantities may revolutionize the field Industrial mass-production MARKET New concepts: Flat-Panel: vacuum or gas Hemispherical (still requires too much handwork) Light Amplifer based on Geiger-APDs (in general)

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54 Very Simple Electronics 57.4 mv 20 kω 1 photo-electron 200 mv 20 kω ZS-2 from Sadygov, MICRON g = 25 1 kω 50 Ω 1 pe 200 mv

55 Superposition of many light pulses in the Geiger-mode APD (signal integrated) Amplitude ~5 photo-electrons 1 V Time

56 Light Amplifier Concept Scintillators + fiber optics NO electronics inside!! READOUT APD array Resolution determined outside!!

57 SMART PMT, QUASAR Spherical LIGHT AMPLIFIER Fiber Plate scintillator Al (100 nm) Geiger-mode APD array 1 photoelectron >15 photons in APD

58 Evaporation Chamber Sealing Chamber Load-lock Chamber TRANSFER SYSTEM For 5 prototypes Base pressure ~6x10-11 Torr

59 Mass spectrometer Sb evaporator Cs, Na, K dispensers Photocurrent monitor

60 Cs, Na, K dispensers

61 Photon Absorption (Electron Creation) Probability for an Electron to Reach the Vacuum Surface (Random Walk) Photon Photo-Electron Glass Window Photocathode Vacuum Therefore: QE ~ 10-20%

62 Photon Absorption (Electron Creation) Probability for an Electron to Reach the Vacuum Surface (Random Walk) Photon Photo-Electron Vacuum Photocathode (e.g. Substrate, Reflector, ) LOW PRODUCTION COST!

63 UV Photon Absorption (Electron Creation) Surface UV Photon Photo-Electron Vacuum Photocathode Probability for an Electron to Reach the Vacuum Surface (Random Walk) Thin Photocathode on a Reflector, Interference Multilayer Systems Westinghouse, RCA, ITT ~

64 Reflection Mode vs. Transmission Mode Quantum Efficiency Extension into blue & UV ~30-43 % QE bialkali ~ nm (Hamamatsu side-on PMT R7517) Wavelength

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67 Transmission-Reflection (and also light trap)

68 Number of Detected Photons APD PMT TransReFerenceerence ReFerence HPD Single-Photon Resolution

69 Photocathode Cooling - Diminished Dark Current Thermionic emission [e/sec/cm 2 ] Cooling InGaAs S Carlsbad NM WATER Cooling (Peltier)

70 e.g. UNO with Magnetic Field (???) VERY EFFICIENT MAGNETIC SHIELDING Slow electrons