High. Resolution Air-shower detector. Ashra Update. On Behalf of the Ashra Collaboration Makoto Sasaki. ICRR, Univ.Tokyo. Ashra Collaboration

Transcription

1 All-sky Survey High Resolution Air-shower detector Ashra Update On Behalf of the Ashra Collaboration Makoto Sasaki ICRR, Univ.Tokyo Ashra Collaboration Y.Aita, Y.Arai, Y.Asaoka, T.Browder, S.Dye, F.Fukagawa, T.Hayashino, W.S.Hou, Y.B.Hsiung, M.A.Huang, M.Ieiri, M.Jobashi, H.Kuze, M.Kimura, T.Kimura, J.Learned, N.Manago, The T.Masuda, 1st International S.Matsuno, Ashra K.Noda, Meeting Univ. A.Okumura, Hawaii (Jan/7-10/2004) S.Olsen, M.Sasaki, N.Sugiyama, H.Usami, M. Z. Wang, Y.Watanabe, M.Yasuda US Taiwan University of Hawaii, Manoa University of Hawaii, Hilo University of Hawaii, IfA Hawaii Pacific University Japan Institute for Cosmic Ray Research, Univ.Tokyo High Energy Accelerator Research Organization National Astronomical Observatory Tokyo Institute of Technology Ibaraki University Tohoku University Chiba University Toho University National Taiwan University National United University 1

2 Ashra Project Neutrino Astronomy Kamiokande Koshiba (1987) Low Energy MeV Water Target ~1000t Crude Pointing ( e ~10 ) Near SN 160K ly Very High Energy PeV (10 15 ev)~zev (10 21 ev) Earth & Air Target ~10 12 t Precise Pointing (~arcmin) Ext.gal. Origin ~500M ly New Tide of VHE Deep Survey Particle Astronomy 2

3 Source Candidates of VHE Particles Gamma Ray Burst Active Galactic Nuclei Proton Acceleration in AGN n CR CMBR CR Earth Studying origin and propagation of VHE CRs Photo-meson Interaction p n p + 0 γ π, π π µ + νµ e + νe + νµ + νµ, π γγ γ Evidence of Ext.gal. p Acceleration ε ε Γ ε ε p GeV, ν st Exam of VHE Particle Astronomy p 3

4 VHE Particle Detection Advantage of Imaging Air-lights Can correct AS development fluctuation event by event =>Convincing E estimation 900m asl Particle ID using mag. field p spread over 1deg. only PSF =>High resolution required Point Spread Spread out due to magnetic Field 4

5 Ashra Detector New VHE Particle Detector System for Cerenkov & Fluorescence Air-lights Distinctive Features: All Sky Survey ~2 sr High Resolution arcmin Simultaneous Observation TeV EHE p/ VHE Wide Angle Fine Optics Modified Baker-Nunn Optics Spherical Mirror segmented Spherical Focal Surface 3 Correcting Lenses Pupil=1m F/0.74 Ashra Station: 12 Detectors / Station 0.5 sr F.O.V / Detector All Sky / 50M pixel Image Pipeline High Resolution, High S/N, Sefl-triggered Details in M.Sasaki et al, NIM A492 (2002) 49 5

6 Ashra-2 Sensitivity for E p ev Ashra-phase2 Auger Stereo Event Rate (duty 10%) E thres ev ev Events/year

7 Tau Neutrino Tau Neutrino Detection using Earth and Mountain Earth Skimming Tau Neutrino ev Tau Cerenkov AS from Mountain Fualalai Mauna Loa (Cillis&Sciutto) Tau dominates appeared leptons VHE 7

8 The tau lepton loses its energy in the rock through 4 kinds of interactions: (1). Ionization (α): the tau lepton excites the atomic electrons. H. A. Bethe 1934 (2). Bremsstrahlung (β): τ τ A (3). Pair Production (β): A. A. Petrukhin &V.V. Shestakov, 1968 τ A τ R. P. Kokoulin & A. A. Petrukhin, 1971 (4). Photo-nuclear interaction: τ γ N F 2 (x,q 2 ) Basic component τ X The nucleus shadowing effect is considered: A 2 2 F2 ( x, Q ) a( A, x, Q ) = N 2 AF ( x, Q ) Brodsky & Lu, 1990; Mueller & Qiu 1986; E665 Collab. Adams et al., 1992 Summarizing all these: 2 8

9 The τ energy loss: Iyer Dutta, Reno, Sarcevic, & Seckel, 01 deτ 2 = α + βi Eτ, X in units of g/cm, dx i α and β ' s are plotted below. i Tau Lepton Range Iyer Dutta, Reno, Sarcevic, & Seckel, 01 Tseng, Yeh, Athar, Huang, Lee, & Lin, 03 Log(E/GeV) Tau lepton range approaches to 20 km in rock. Mountain-penetrating is sufficient! 9

10 Energy of Tau from GZK Arbitrary Unit Tau shower energy peak at E=100PeV (10 17 ev) Significant contribution from regenerated tau at E<100PeV Importance of both Cerenkov and fluorescence detections Shape of Appeared Tau from GZK Tau Elevation Angle Shower Max. Position Clear evidence of AS originated from Earth => Directional precision 10

11 Integrated tau lepton flux in units of km -2 yr -1 sr -1 by G.-L.Lin Guaranteed Source Energy & flux ev AGN 2.2 GRB GZK ev ev ev W resonance (AGN) 0.08 Effective aperture (AΩ) eff required for 1 event/yr, assuming a 10% duty cycle. Energy & Aperture (km 2 sr) ev AGN 4.5 Guaranteed Source GRB 1000 GZK ev ev ev 290 GZK- Highly Plausible Detection by Ashra 11

12 Neutrino Sensitivity 1 event/year/decade of energy (curve) 90% upper limit assuming E -2 flux (straight line) Interaction in mountain has not been taken yet. Ashra Cerenkov + Fluo. Ashra Ceren. 100TeV Ashra Fluo. 10PeV Ashra can keep good sensitivity in whole range E>100TeV Great Chance of the first clear detection VHE Neutrino showers Test Observation 12

13 Test Plan Design Prototyping Test Obs. in Hawaii Optics 2/3 Scale Prototype GRB Optical Flash Search Image Pipeline TeV Source Tracking w/ alt-azimuth Ashra Optics Modified Baker-Nunn pupil : 1m F/0.74 Details can be found in M.Sasaki et al, NIM A492 (2002) 49 Schmidt-type optics Spherical segment mirror Spherical focal surface 3-element corrector lens Photocathode of Lens IIT 13

14 Lens IIT Finished 16 UV-Ray Image Intensifier Tube Examples of output images Lens IIT Performance: Resolution Image of Resolution Chart Point light source chart Setup UVII Camera Lp/mm Input 50Lp/mm Output 14

15 Lens IIT Performance: Gain Distribution Single photoelectron response measured w/ 415nm pulse laser psec laser Setup ( # of events) # of photons 100 Signal (mv) Lens IIT PMT 100ns Gain distribution (ADC counts) Decay curve Time (ns) First Light NOAJ Camera Lens-II rail 2/3-scale Ashra optics prototype Spot size of star image: ~2 arcmin. Concept of wide angle fine optics has been realized. 15

16 Test Observation (1) with Ashra Prototype Optics 1 50 FOV Close-up view of the Pleiades Image Taken at Haleakala Pegasus 16

17 Live Time Ashra Proto for Opt. Flash Possible Live time astronomical twilight end to astronomical twilight begin &Moon bright area rate<10% astronomical twilight =>Elevation of Sun between -20 and -18 Ashra Proto for Gamma Catching GRB :51:48 UTC Notice :31:50 UTC HETE2 WXM 4sec Exposure every 5sec with 11M pixels 12:51:48 UTC Notice ~2000 images are taken 17

18 GRB Obs.. Results GCN GCN 9 Ashra -1500sec Light Curve GRB Ashra successfully waited for the optical flash continuously over the GRB time. RAPTOR 4837sec, Mag> sec, Mag> x10 4 sec, Mag>20 Sari & Piran (99) Comparison of GRB Optical Observation FOV sr Wavelength band Limit mag. / exp.time Start RAPTOR Sensitive area cm 2 Resolution arcmin RAPTOR -A,B wide R 12 / 30sec Ashra -P2/ ~B 14 / 4sec Even Ashra Prototype Test Observation => Fairly Competitive 18

19 Ashra Image Pipeline To reduce image size into a solid state imager Electric Lens Effect Big reduction in pixel cost UVII 1. Amplification of image intensity w/ pipelined IITs. 2. Self triggering using light splitting 3. Fine imaging w/ CMOS sensor Details can be found in M.Sasaki et al, NIM A501 (2003) 359 New Prototype of Image Pipeline 19

20 Test Observation (2) with Ashra Prototype Image Pipeline TeV gamma ray observation using an alt-azimuth mounting telescope AS Cerenkov Images 20

21 TeV- All-sky Survey by Ashra 3030m a.s.l clean air Low night sky BG Long time all sky simultaneous observation 21

22 Elements Under Development 22

23 Trigger Readout System MAPMT Trigger Sensor Ashra Trigger Sensor ASIC LSI Pixel Layout Design Rule CMOS Standard Process 0.35µm 2-poly, 3-metal Chip size: 4.9 mm 23

24 Ashra Fine Sensor ASIC 2-Dim Exposure&Readout By Outer Control Signals Ashra Fine Sensor Overlap Process 24

25 Summary Advanced capabilities of Ashra: Wide Angle Fine Image Optical System Self-trigger of Cerenkov Images with the Pipeline System have been demonstrated at Haleakala. Installation at Mauna Loa starts spring: Adjustment of the optical system with star images => Search for optical transients simultaneously. Cerenkov and fluorescence triggers will be implemented step by step. => Start all-sky survey of TeV sources in FY2005. Mauna Loa Site Mauna Kea Inversion Layer Mauna Loa Side