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MOON ... M olybdenum O bservatory O f N eutrinos. H. Ejiri et al. PRL 85 (2000) 2917. Physics Goals:. Low Energy Solar Neutrino Spectroscopy Search for 0 in 100 Mo Supernova Neutrino. Peter Doe, University of Washington NeSS 2002, Washington DC, 19 - 21 September, 2002. 100 Mo.
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MOON...Molybdenum Observatory Of Neutrinos H. Ejiri et al. PRL 85 (2000) 2917 Physics Goals: • Low Energy Solar Neutrino Spectroscopy • Search for 0 in 100Mo • Supernova Neutrino Peter Doe, University of Washington NeSS 2002, Washington DC, 19 - 21 September, 2002
100Mo Why Low Energy Solar Neutrinos?
Why 100Mo? • Eth = 0.168 MeV • pp + 7Be Solar Neutrino spectroscopy in real-time • Large CC rates • Raw rates/ton100Mo/year = 40 7Be, 120 pp • Signal = Two coincidence • Suppress backgrounds • Directly determine neutrino absorption cross section - Garcia et al. Solar- capture rates (SNU) A; Bahcall 88, b; Bhattacharya, c; Ejiri 98, d; Ejiri 99
Solar Neutrino Signal: • Inverse beta decay: E= 0.115 MeV • Followed by: • Beta decay 100Tc: E= 0.63.2 MeV, =16s Detector Requirements: • Mass 100Mo 1 ton • Purity mBq/ton for U, Th isotopes • Time resolution 2 Coincidence • T~1 30s (solar & Supernova ), 2ns ( ) • Spatial Resolution • V~10-9 ~3mm (solar & Supernova ) • Energy resolution • E~0.12/E 1/2 Mev (~7% at 3 MeV) • Dynamic range • E ~0.1 40 MeV (solar & Supernova )
Detection Techniques under Consideration: • Scintillator Mo Foil Sandwich • Mo loaded liquid scintillator • Cryogenic calorimeter One possible configuration scintillator Readout fibers • 1 module: • Mo foil, 6m x 6m x 0.05 gm/cm • Scintillator 6m x 6m x 0.25cm • 222 wavelength shifting fibers • Super module (detector) • 1950 Modules • 6m x 6m x 5m • 34 t nMo (3 t 100Mo) • 13600, 16-anode PMT readout • Rate pp - 7Be ~ 0.3 - 0.1 /ton/day Mo foil
Ongoing R&D: • Mo Loaded Liquid Scintillator • 0.3 -0.7% Mo by weight • ~3.5 103 photons/MeV • Avalanche Photo diode readout • High quantum efficiency • Wavelength shifting fiber readout E~2E-1/2~11% at 3MeV X~0.8 E-1/2~0.5cm Need to increase photon yield by 2.5 Anticipate ~2 year R&D, then freeze detector design
Laboratory Requirements: • Depth > 4000 mwe • Radon < 10 Bq/m3 (10 mBq/m3 in detector) • Cavity ~ 10m, 10m, 20m (includes staging area) • + counting and control room The MOON Collaboration: • H.Ejiri, N. Kudomi,s. Yoshida • RCNP, Osaka Univ. Japan • R. Hazama, K. Nomahci, K. Matsuoka, Y. Sugaya • Phys. Dept. Osaka Univ. Japan • P.J. Doe, V. Gehman, R.G.H. Robertson, J.F. Wilkerson, D. Will • CENPA, Univ. Washington Seattle, USA • J. Engel • Phys. And Astronomy, Univ. North Carolina, USA • P. Krastev, • IAS, Princeton, USA • M. Finger • Phys. Dept., Charles Univ., Prague, Czech Republic • A. Gorin, I.Manouilov, A. Rjazantsev • Inst. High Energy Physics, Protvino, Russia In Association with: The Majorana Collaboration F. Avignone, C. Aalseth S.R. Elliott, H. Miley…...