Status of the MAGIC Gamma-ray Observatory. Novel Photosensor Development at UC Davis

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1 Status of the MAGIC Gamma-ray Observatory Brief Overview of MAGIC August data taking Novel Photosensor Development at UC Davis Daniel Ferenc, UC Davis

2 1. MAGIC Gamma-ray Observatory Daniel Ferenc (UC Davis) for MAGIC MAGIC-1 MAGIC-1 is now operational and is taking physics data

3 MAGIC Colaborators: IFAE Barcelona, UAB Barcelona, Humboldt U. Berlin, UC Davis, U. Lodz, UC Madrid, MPI München, INFN / U. Padova, U. Potchefstrom, INFN / U. Siena, Tuorla Observatory, INFN / U. Udine, U. Würzburg, Yerevan Physics Inst., ETH Zürich

4 Daniel Ferenc Eckart Lorenz (became a UCD Adjunct Faculty) Daniel Kranich (Feodor Lynen Fellow) Alvin Laille (Graduate Student) University of California Davis

5 La Palma, Canary Islands 28 North, 18 West

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7 What Happened to HEGRA? 2 telescopes! Los Alamos, MILAGRO 3 telescopes! Croatia New project: CROATEA (Cosmic Ray Observatory at the Eastern Adriatic)

8 1-Year Observation Time!!! 50 Hours Observation Time

9 MOTIVATION: 2. Counterparts of Gamma Ray Bursts at higher energies & Transients in general (like AGNs, Mkn 421, Mkn501) 1. High Sensitivity for the very important energy interval 10 GeV < E < 100 GeV 1-Year Observation Time!!! The extinction interval for many sources that have been observed at low energies (EGRET) and invisible 50 Hours at high energies (ground-based IACTs) Extended gamma-ray horizon at low energies: - AGN studies per se, and - EBL (IR) background studies, galaxy and star formation

10 Observation H. Krawczynski, multiwavelength campaign proposal

11 Primack et al., 2001

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14 Time The Implications of Galaxy Formation Models for the TeV Observations of Current Detectors, L.M. Boonet, J.S. Bullock, J.R. Primack, D.A. Williams, CP515, GeV-TeV Gamma Ray Astrophysics Workshop, edited by B. L. Dingus, et al.

15 Cherenkov Photon Density at Low Energies

16 Fight for every Cherenkov photon EFFICIENT PHOTON COLLECTION Very large collection (mirror) area High mirror reflectivity Efficient light concentration into PMTs HIGH PHOTON DETECTION EFFICIENCY Quantum Efficiency Wide Spectral Coverage

17 MAGIC is based on numerous important innovations Fight for every Cherenkov photon EFFICIENT PHOTON COLLECTION Very large collection (mirror) area High mirror reflectivity Efficient light concentration into PMTs HIGH PHOTON DETECTION EFFICIENCY Quantum Efficiency Wide Spectral Coverage

18 The MAGIC Observatory MAGIC-1 Telescope is now ~fully operational!! currently the largest ACT in the World Mirror area = 234 m 2 (diameter = 17 m) Field of view = 3.5 o The Effective gamma-ray detection area >10 4 m 2 Current trigger threshold estimated ~ 50 GeV MAGIC-2 is under construction (independent or stereoscopic mode together with MAGIC-1) A 1000 m 2 telescope ECO-1000 has been studied

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20 MAGIC is based on several key innovations

21 LIGHTWEIGHT FRAME (Carbon Fiber) for fast rotation (<20 seconds) for Gamma Ray Bursts

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23 SUPER-EFFICIENT CAMERA

24 Maximizing Double-Hits in a PMT PMT Not yet optimized for the milky PMT coating " Significant additional improvements to come

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31 MIORROR CONTROL Focusing a star

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33 NEW FADC 2 GHz R&D funding secured at MPI

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36 MAGIC Inauguration October 10, 2003 Photo: Prof. Winston Ko

37 Technical runs and fine tuning - until summer 2004

38 Summary high energy analysis Mkn421 night selection (size) ontime (min) Rate (/min) 15 / 02 > / 04 > / 04 > / 04 > Note: systematic effects may still be present in the analysis Due to the incomplete and changing configuration

39 Mkn421 April 04 energy dependence Analysis in slices of the parameter size; in (red): most probable energy photons photons photons. (75 GeV) (102 GeV) (160 GeV)

40 SUMMER 2004 DATA TAKING (close to the design performance)

41 August 2004 Data Taking Crab, 252 min 3C66A, 536 min 3EG , 213 min 1ES1426, 18 min 3EG , 395 min Mrk501, 26 min

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48 VERY PRELIMINARY NOTE Large Zenith Angle!

49 VERY PRELIMINARY

50 VERY PRELIMINARY VERY PRELIMINARY Still Large Zenith Angle, deg.

51 VERY PRELIMINARY

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53 SUMMARY MAGIC-1 Telescope is taking physics data > August 2004 Low detection threshold >50 GeV with classical Hillas parameter-type analysis <50 GeV more sophisticated analysis methods are under development Image shapes are more complex Cosmic diffuse electron background stronger than hadronic! (Muons no problem) deg. zenith angle (high threshold >200 GeV), ~6.5 sigma for ~30 minutes observation time AGNs at low energies: z~0.03 technical data, but already a very strong signal z~0.44 August 04, physics data, analysis under way! Others MAGIC is based on many important innovations. Still working on some (photosensors, light collectors, fast FADCs, mirror control, analysis software). Crucial for low threshold Available for other gamma-ray astronomy projects. Spin offs National Security, Medical Imaging.

54 Development of Novel Photosensors at UC Davis Daniel Ferenc Eckart Lorenz (became Adjunct Faculty at UC Davis) Daniel Kranich (Feodor Lynen Fellow) Alvin Laille (Graduate Student) University of California Davis

55 MOTIVATION: Unique importance of Photosensors for Next-Generation Projects in HE Physics and Astrophysics Similar importance for Homeland Security

56 Future projects are aiming to study very rarely occurring phenomena - Proton decay, Neutrino Physics and Astrophysics UNO, MEMPHIS, HYPER-K, Kilometer-Cube, also Nestor, Nemo, Antares, etc. - Gamma-ray Astronomy a study of faint and/or variable sources requires telescopes with low detection threshold & wide acceptance angle - Ultra-high energy cosmic rays (>10 19 ev) P. Auger, EUSO, OWL, - Double beta decay

57 SEARCHING FOR EXTREMELY RARE AND WEAK RADIATION SOURCES PARTICLE ASTROPHYSICS (new generation of experiments) HOMELAND SECURITY

58 Work supported by the: (1) Advanced Detector Research Award DOE/HEP Novel Highly Sensitive Photosensor Technology for Inexpensive Large Area Cherenkov Detectors and (2) National Nuclear Security Administration (NNSA), Office of Nonproliferation Research and Engineering Proposal for a Super-large Radiation Detector Based on ReFerence Flat-Panel Photosensor Concept

59 New Experiments need sensitivity for very rare phenomena Very Large Volumes/Areas No No other other choice choice than than Natural Transparent Media (Water, Atmosphere, Ice) PHOTOSENSORS

60 Several unconventional photosensor concepts Flat-Panel ReFerence Camera Concept (Patented) Light Amplifier concept, development just started SIMPLE Imaging Camera Concept, project idling, (Patent Pending) A New Concept currently secret (patentable?)

61 Cherenkov angle in air < 1 degree, also well defined observational direction, and small angular spread in the EM shower " Liouville s theorem allows significant beam area reduction " The Camera can have a small area MAGIC Telescope Inauguration, October (Photo-W. Ko)

62 SuperKamiokande Cherenkov angle in water ~40 degrees "Liouville s theorem still allows slight beam-area reduction (see AQUARICH) " Camera must be large

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64 Why the old PMT technology is not satisfactory? PMTs are ~hand-made: - Glass bulbs (glass-blown) - Dynode chains are hand-assembled - Wire connections spot welded - Installation and handling is complex and risky Intrinsically very expensive technology Large-Scale production is virtually impossible

65 OBJECTIVES 1. Large Photosensor Area Coverage High Quantity High Quality Low Price "Industrial Mass Production 2. High Detection Efficiency and S/N (collection and quantum efficiency)

66 OBJECTIVES 1. Large Photosensor Area Coverage High Quantity High Quality Low Price "Industrial Mass Production WHY NOT ACCOMPLISHED ALREADY???? 2. High Detection Efficiency and S/N

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

68 Irreducibly Large Illuminated Area Photosensors with Very strong internal information concentration! Vacuum More efficient photocathodes Industrial Mass-Production at a very low cost < 5% of PMTs per square meter

69 Development of Other Vacuum Devices ~1960 ~2000

70 Flat Panel Camera wishful thinking: Continuous Hybrid Photon Detector (HPD) PiN, APD, something else window electrons vacuum Reflection-Mode Photocathode

71 This doesn t work! Problem #1 Electron Optics e e e

72 Problem #2 Mechanical Stability (flat plates need supports)

73 Flat-Panel Camera Configuration! provided by the ReFerence Photosensor Concept

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

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

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

78 3 rd ReFerence Prototype (tested) 3 diameter, single pixel (successfully tested see below)

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80 Photocathode

81 XYZ Motion Stage

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84 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 transmission efficiency)

85 ReFerence Panel Prototype (under construction)

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88 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%

89 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!

90 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 ~

91 Reflection Mode vs. Transmission Mode Quantum Efficiency Extension into blue & UV ~35-40 % QE bialkali Wavelength

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

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

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

96 UC Davis Ideas, enthusiasm, physicists Running Projects Equipment (>$2M value) For Photocathode development: Surface Science laboratory: AES, XPE, SIMS, For Flat Panel manufacturing: 2 Flat Panel Sealing Devices (IR Laser Sealing) Several Transfer UHV Systems!!! Night Vision production machine Laser Sealing System (2)

97 WHAT WE NEED: " NEW PHYSICS