SADCO

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• SADCO
• Sea Acoustic Detector of Cosmic Objects
• status of a pilot experiment in the Caspian Sea
• Igor Zheleznykh, INR, Moscow
• for SADCO collaboration
• John Learned reporting a Stanford, 14 Sept 2003
• Introduction
• Short history of HENA.
• Need in cubic km-size (KM3) detectors for
  HENA
• Hydro-acoustical method of UHE(EHE) cosmic
  neutrino detection
• 30 years of its development for UHENA
  and EHENA
• Russian Navy stationary hydro-acoustical
  antennae for HENA Kamchatka array AGAM of 2400
  hydrophones
• Portable submarine antenna of 132 hydrophones as
  a basic module
• of a deep-water acoustic neutrino
  telescope status and prospects

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• Introduction.
• First estimations and comparison of
  atmospheric and astrophysical HE (E 1-1000 GeV)
  neutrino fluxes had been carried out in 1958-1960
  (Markov and Zh.) and Greisen (1960).
• Fluxes of HE atmospheric neutrinos are
  higher than astrophysical ones produced by
  standard Cosmic Rays.
• But productive point astrophysical
  neutrino sources might exist!

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• So underground (underwater) HE neutrino
  experiments were suggested (M.A. Markov et al)
  for investigations of 2 problems
• -- High-Energy Neutrino Physics
• Investigation of neutrino interactions
  with matter using available atmospheric neutrinos
  with energies 1-1000 GeV
• (energy growth of neutrino
  cross-sections, intermediate bosons etc)
• -- High Energy Neutrino Astrophysics (HENA)
• Search for fluxes of HE cosmic neutrinos
  from astrophysical objects.

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HE neutrino (gammas) sources discussed in 1958
1961 Galaxy center, SN remnants (Crab
Nebula) HE gammas (as well as HE neutrinos)
are produced in the strong interactions HEGA was
suggested as complimentary to HENA HE cosmic
neutrinos (as well as gammas) indicator of the
most energetic (strong) processes in hot places
of the Universe so detection of cosmic neutrinos
might be a new branch of Astronomy which is
complimentary to Electromagnetic Astronomies
(optical, radio, X-ray) M.A.Markov, Proc.
Rochester Conf. (1960) p. 579
I.M.Zheleznykh, Diploma paper, Depart. of Phys.,
Moscow Univ., 1958 I.M.Zheleznykh and
M.A.Markov. In High-energy Neutrino Physics
D-577, Dubna (1960)
M.A.Markov and I.M.Zheleznykh, Nucl. Phys. 27
(1961) 385
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In 70th it was understood that kiloton HE
neutrino telescopes which were under
construction (Baksan et al) would not be able to
register HE cosmic neutrinos. 1975 Fred Reines,
John Learned, Arthur Roberts, Vic Stenger et al
idea of Gigaton underwater HE Neutrino Telescope
(DUMAND). 1976 - 1979 Gurgen Askaryan et al, Ted
Bowen, John Learned idea of hydro-acoustic UHE
neutrino detection. So KM3 cubic km - scale
detector for HE and UHE Neutrino Astrophysics
(Astronomy) is needed ! (M.Shapiro,
Silverberg, Beresinsky et al)








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New arguments to support construction of
large-scale (DUMAND- type) NT for
investigations of super GZK- particles were
discussed in the end of 70th begin of 80th by
M.A.Markov and his group --the possibility of
the existence of particles with energies
1020-1028 eV originating in the decays of the
Mini-Black Holes --maximons (particles with
Plank mass) and EHE particles --neutrinos with
energies above 1020 eV as a result interactions
(decays) of the hypothetical super heavy
particles M.Markov and I.Zheleznykh,
Proc. DUMAND-1979, p.177 V.Maltsev and
M.Markov (1980), V.Frolov and M.Markov, (1979)
L.Dedenko, M.Markov and I.Zheleznykh, Proc.
Neutrino-81, Maui, p.92 (in this paper the
suggestion was also made to search for the
electron-photon and hadron cascades produced by
super-GZK neutrinos in the atmosphere by radio
method)

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• Topdown models and possible EHE neutrino sources
  
• discussed last years
• decays of topological defects (see G.Sigl, 2002)
• decays of long-living X-particles with masses
  1022 - 1026 eV
• Kuzmin and Rubakov, 1997
• Beresinsky et al., 1997
• Such objects are objects of much interest for
  HENA
• (and hydro-acoustical UHE and EHE neutrino
  detection!)

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II. HYDRO-ACOUSTICAL DETECTION of
neutrino-induced cascades
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SADCO in the MEDITERRANIEN. Acoustical
background measurements, 1991
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III. New Era of SADCO since 1997 to use Russian
Navy stationary antennae
for
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IV. PORTABLE SUBMARINE ANTENNA MG-10M as a basic
module of the deep-water Neutrino Telescope
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• SADCO collaboration have now
• one MG-10M antenna of 132 hydrophones,
• Agreement with a plant in St.Petersburg to make
  necessary tests of this antenna,
• Agreement with Azerbaijan Ac. Sci.,
• programs for simulations acoustic signals from
  cascades in water, transportation of the signals
  in the
• Real Ocean etc.

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Table. Parameters of cascades in water with
the LPM-effect
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Distribution of energy deposition by1018
electron in water with the LPM-effect
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Comparison of distribution of energy depositions
by 1019 and 1018 electrons in
water (with the LPM-effect)
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Comparison of distribution of energy depositions
by 1020 and 1018 electrons in
water (with the LPM-effect)
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Distribution of frequencies of
acoustic signals at 0.4 1 3 10 km
by the electron cascade of 1021 eV in water with
the LPM-effect
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Distribution of energy deposition by
1021 eV electron in water with the
LPM-effect
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Acoustic pulses at distances of 0.4
1 3 10 km by the electron cascade
of 1019 eV in water with the LPM-effect
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Dependence of the peak value of acoustic signal
on distances for various energies of cascades
10181021 eV in water with the LPM-effect
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Dependence of the peak value of
acoustic signal on shifting of the
observation point along the cascade length
for the 1018 eV electron cascade at 400 m
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Could Russian Navy help to HENA in searches for
topological defects in our Universe? Yes,
they could. USA Navy?
We should ask G.Gratta. French Navy?
We should ask L.Moscoso. It would be
great if to cooperate!
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