1 / 37

PeV Cosmic Neutrinos from the Mountains

PeV Cosmic Neutrinos from the Mountains. Ping Yeh ( 葉平 ) National Taiwan University November 15, 2002 CosPA 2003 @ NTU, Taipei. Today is the 75th Birthday of NTU!. Ultra-High Energy Cosmic Rays. Origin. Anisotropy. Fly’s Eye P(fluct) < 0.07.

beck
Download Presentation

PeV Cosmic Neutrinos from the Mountains

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. PeV Cosmic Neutrinos from the Mountains Ping Yeh(葉平) National Taiwan University November 15, 2002 CosPA 2003 @ NTU, Taipei Today is the 75th Birthday of NTU!

  2. Ultra-High Energy Cosmic Rays Origin Anisotropy Fly’s Eye P(fluct) < 0.07 D.J. Bird et al., Ap. J. 511, 738astro-ph/9806096 AGASA 4% excess M. Teshima et al.,27th ICRC p337, 2001

  3. High Energy Cosmic Neutrinos Production presumably dominated by nm and ne Hadronic Transportation & Oscillation: 1:1:1

  4. UHECR + CMB  N +   GZK  Cosmic Rays and Neutrinos Cosmic Ray Spectrum CR + X    e2e ~ 1.2 x 103 /PeV/year/km2/sr Not Well Understood AGN ? GZK  Firm! ~ 0.1 /EeV/year/km2/sr

  5. Observing High Energy Cosmic Neutrinos Principle: convert neutrinos to observables Low cross section: need large target volume Signals development: need large detection volume Mostly use H2O as target and detection volume (Bikal, AMANDA, ANTARES, IceCube) Energy coverage: H2O, air fluorescence, and the “hole”

  6. Conventional n Detectors: Atm/Solar SNO SuperK Shield from CR & Atmospheric ’s: Underground Under Water/Ice Very Large Target Volume = Detection Volume solar  deficit/ &  

  7. Conventional High Energy n Detectors Yoshida’s talk Deployment: 2003 - 2009 Existing Limited by Target Volume:Maximum Energy ~ 1015 eV

  8. IceCube: 1 PeV Limit for nt

  9. UHECR Detectors Auger Detect -induced Air Showers Conversion Efficiency in Atmosphere Small Reflected Fluorescence  Energy Threshold High > 1018 eV

  10. Window of Opportunity UHECR n Detector Conventional n Detector ?

  11. Protons? AGN Jets, CRs and    ?

  12. Earth Skimming Earth Skimming + Mountain Penetrating Cherenkov vs. fluorescence Cross Section ~ E1.4 Telescope    t appearanceexperiment! Sensitive to nt ne: electron energy mostly absorbed in mountain nm: no extensive air shower 

  13. Collaboration • Italy: IASF, CNR, Palermo • N. La Barbera, O. Catalano,G. Cusumano, T. Mineo,B. Sacco • France: Paris, FranceF. Vannucci, S. Bouaissi • USA: HawaiiJ.G. Learned • Japan: ICRRM. Sasaki • Taiwan: • NCTS/CosPA3 • G.L. Lin, H. Athar, … NTUHEP/CosPA2 PIs: W.S. Hou & Y.B. Hsiung Hardware Team: K. Ueno (Faculty) Y.K. Chi (Electronics) Y.S. Velikzhanin (Electronics) M.W.C. Lin (Technician) Simulation Team: M.Z. Wang (Faculty) P. Yeh (Faculty) H.C. Huang (Postdoc) C.C. Hsu (Ph.D. student) NUU M.A. Huang (Faculty) Formed in Spring 2002

  14. Rates, Rates? Rates! Figure of merit for the experiment Diffused source vs point source Flux: different sources, different models Acceptance: Maximizing A(E) within the budget constraint is the design goal

  15. Feasibility Feasibility study was done in 2002 (Alfred Huang) Assume: aperture = 1 m2, light collection efficiency = 10%, ~ 40 km wide valley, ~ 2 km high mountain Conclusion was O(1) events per year Deemed feasible, more attractive with a small budget, and was funded that way More detailed study in 2003, will be shown

  16. Acceptance Figure of merit of the telescope design A = integration of detection efficiency in the phase space (x, y, theta, phi) Detection efficiency depends on aperture & field of view light collection efficiency trigger logic

  17. Factors for Acceptance The chain of conversions nt to t conversion rate: ~ O(10-5) - O(10-4) Expect O(10) /year/km2/sr t flux > O(1) km2 sr acceptance desired t decay: ~ 82% branching fraction for showers Light collection (baseline design): 1 m2 aperture, 8o x 16o field of view, ~ 10% efficiency Trigger: position dependent

  18. The Signal and Background Pattern Cherenkov: ns pulse, angular span ~ 1.5 degrees Night Sky Background (mean) Measured at Lulin observatory: 2.0 x103 ph/ns/m2/sr A magnitude 0 star gives 7.6 ph/m2/ns in (290,390) nm Cosmic Ray background very small Cluster-based trigger algorithm Random Background with NSB flux 1 km away from a 1 PeV e- shower

  19. Trigger Study Background Rates vs Signal Efficiency 1PeV, 30 km, normal incidence Trigger Rate (Hz) H-L Trigger Single Trigger Y H-H Trigger (Dual trigger) X 1PeV, 30 km, 10° incidence H threshold Local coincidence necessary to kill the background!

  20. Acceptance Determination Integration of efficiencies in phase space Three independent methods for cross-checking Results are consistent with each other!

  21. Acceptance Curve Estimated with an idealistic vertical plane mountain surface Acceptance starts at Et ~ 1 PeV Gradually levels off near 1 EeV (t decay length = 50 km @ 1 EeV)

  22. E, x, y, ,  N1, T1, x1 , y1,1, 1 N2, T2, x2 , y2,2, 2 2 1 Preliminary Reconstruction • Reconstruction: Minimize 2 for x,y,,, and E • Two Detectors Separated by a few 100m

  23. Reconstruction Error • Possible to Reconstruct Events • Angular Error within 1° • Energy Error ~ 40% • Reconstruction Efficiency 30% ~ 70%

  24. Sensitivity • Sensitivity : 1 event/year/decade of energy • Great Chance to See  from • AGN • TD • GC Attenuation is an Issue

  25. Requirements on the Instrument Find signal on top of background! Rate >= 0.5 events/year aperture, light collection efficiency, trigger Angular resolution: 0.5 degrees or smaller Timing (ns pulse) Low budget

  26. Prototype Telescope • Purpose: • Proof of Concept • Measure Background • Telescope • Commercial Fresnel Lens (NTK-F300, f30cm, size=30cm, pitch=0.5mm, PMMA UV), • UV Filter (BG3) • Hamamatsu 4x4 (H6568) MAPMT • Readout Electronics: Preamp, Receiver, Trigger, ADC and DAQ

  27. Field Test at Lulin Observatory (2900m) 3 elevation angles: 3°, 7°, 15° 2 conditions: w/o BG3 filter 15° Sirius 7° 3° 玉山 (Mt. Jade) 0° E

  28. Cosmic Rays • CR tracks seen by prototype telescope • System functions properly • Potential Use: • Monitor System Health • Calibration by CR events

  29. The Optics Want to utilize existing mirrors or lenses First concept: EUSO-type Fresnel lens Note that EUSO is years away Timely readiness and cost!

  30. The Optics - revised • Current direction: ASHRA-type Mirror + correction lens • Photon Sensor: Multi-Anode Photomultiplier • Don’t need arc-min resolution: optics is basically ready NOW Sasaki’s talk

  31. The Electronics Dynamic Range x4

  32. cycle RAM buffer RAM cycle RAM buffer RAM Preamp. FADC FADC PMT Trigger Trigger DAQ DAQ Preamp. PMT Schematics of the Electronics Mirror 16 RAM x 256 x 16 per 8 channels Signal-sharing plate UV filter ADC control FPGA (x4) 10 bit x 40 MHz Pipelined ADC Start readout Trigger FPGA Detector pair To/from Another DCM UV filter 10 bit x 40 MHz Pipelined ADC Start readout To/from Another DCM 16-channels preamplifier Hamamatsu 8x8 MPMT Front-end electronics box 8x8 pixels (1 MPMT, 1 SSP, 4 preamplifiers) 32 – channels DCM (Data Collection Module) in cPCI

  33. Calibration: Pointing Crab Nebula as the standard candle Can we see it? d J / d E = 0.28 * ( E / 1TeV ) -2.6 km-2 s-1 TeV-1 Integrated flux is not small: 0.3 /km2 /s Random background > 10 times higher in “stary stary nights” Use neutral density filter + tighter trigger

  34. 1 TeV gamma Distance (m) Acceptance to the Crab • Acceptance ~ around O(0.1) km2 sr • Rate ~ 6 events/hr • Exposure of several nights would be useful Photon density (1/m2 ) Trigger Range (m) log E (TeV)

  35. Site • Primary Site: Mt. Hualalai looking at Mauna Loa • Good weather condition, less background, GC in FOV • No electricity, no water, no communication • Prototype Site: Mauna Loa looking at Mauna Kea • Infrastructure ready, on-site help from CosPA1! • No GC observation Mauna Kea Mauna Loa Mt. Hualalai Still looking for possible sites!

  36. Schedule 2003 2004 2005 Detector Design Site Survey / Preparation Construct 1024 Ch. Prototype Crab’s itinerary dictates October - December Prototype Operation Construct Full-size Telescope Installation & Calibration Full Telescope Operation

  37. Conclusion • NuTel is the first experiment dedicated to Earth skimming / mountaing watching • The PeV cosmic nt rate is a few events/year • The cost is low: O(1) million US dollars to build it • The time is short: prototype deployment in 2004 • The window of opportunity is good, both in energy and time (Hmm… the uncertainty principle?) • Ashra is a natural continuation for NuTel • Site coincides • Physics complimentary • Schedule looks promising

More Related