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TOPIC: IceCube
Blobrana


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RE: IceCube
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Title: Supernova Neutrino Detection with IceCube
Authors: Lutz Köpke for the IceCube Collaboration

IceCube was completed in December 2010. It forms a lattice of 5160 photomultiplier tubes that monitor a volume of ~ 1 cubic km in the deep Antarctic ice for particle induced photons. The telescope was designed to detect neutrinos with energies greater than 100 GeV. Owing to subfreezing ice temperatures, the photomultiplier dark noise rates are particularly low. Hence IceCube can also detect large numbers of MeV neutrinos by observing a collective rise in all photomultiplier rates on top of the dark noise. With 2 ms timing resolution, IceCube can track subtle features in the temporal development of the supernova neutrino burst. For a supernova at the galactic center, its sensitivity matches that of a background-free megaton-scale supernova search experiment. The sensitivity decreases to 20 standard deviations at the galactic edge (30 kpc) and 6 standard deviations at the Large Magellanic Cloud (50 kpc). IceCube is sending triggers from potential supernovae to the Supernova Early Warning System. The sensitivity to neutrino properties such as the neutrino hierarchy is discussed and simulations of tantalizing signatures, such as the formation of a quark star or a black hole as well as the characteristics of shock waves are presented. All results are preliminary.

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Blobrana


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IceCube Project at the South Pole



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Blobrana


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Posts: 131433
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Antarctic neutrino telescope
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Antarctic neutrino telescope celebrates completion with conferences, public events

This week, researchers from around the world are gathering in Madison to mark the completion of the IceCube Neutrino Observatory at the South Pole.
The University of Wisconsin-Madison, the lead institution on designing, building, and now operating the massive telescope, will host an Antarctic science symposium on April 27-28 and a meeting of particle astrophysicists on April 29-30 to celebrate the detector's completion and look ahead to the future of physics research on the southernmost continent and elsewhere. The larger IceCube collaboration, which includes researchers from Germany, Sweden, Belgium, and over 30 other countries, will also gather to discuss progress and future directions for the detector, which has been collecting data since early 2005. The meetings will be held at the Monona Terrace Community and Convention Centre in Madison.
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Blobrana


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Posts: 131433
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RE: IceCube
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Title: Limits on Neutrino Emission from Gamma-Ray Bursts with the 40 String IceCube Detector
Authors: IceCube Collaboration: R. Abbasi, Y. Abdou, T. Abu-Zayyad, J. Adams, J. A. Aguilar, M. Ahlers, K. Andeen, J. Auffenberg, X. Bai, M. Baker, S. W. Barwick, R. Bay, J. L. Bazo Alba, K. Beattie, J. J. Beatty, S. Bechet, J. K. Becker, K.-H. Becker, M. L. Benabderrahmane, S. BenZvi, J. Berdermann, P. Berghaus, D. Berley, E. Bernardini, D. Bertrand, D. Z. Besson, D. Bindig, M. Bissok, E. Blaufuss, J. Blumenthal, D. J. Boersma, C. Bohm, D. Bose, S. Böser, O. Botner, J. Braun, A. M. Brown, S. Buitink, M. Carson, D. Chirkin, B. Christy, J. Clem, F. Clevermann, S. Cohen, C. Colnard, D. F. Cowen, M. V. D'Agostino, M. Danninger, J. Daughhetee, J. C. Davis, C. De Clercq, L. Demirörs, O. Depaepe, F. Descamps, P. Desiati, G. de Vries-Uiterweerd, T. DeYoung, J. C. Díaz-Vélez, M. Dierckxsens, et al. (205 additional authors not shown)
(Version v2)

IceCube has become the first neutrino telescope with a sensitivity below the TeV neutrino flux predicted from gamma-ray bursts if GRBs are responsible for the observed cosmic-ray flux above 10^{18} eV. Two separate analyses using the half-complete IceCube detector, one a dedicated search for neutrinos from p \gamma-interactions in the prompt phase of the GRB fireball, and the other a generic search for any neutrino emission from these sources over a wide range of energies and emission times, produced no evidence for neutrino emission, excluding prevailing models at 90% confidence.

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Blobrana


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IceCube Neutrino Observatory
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Title: Searching for sterile neutrinos in ice
Authors: Soebur Razzaque, A. Yu. Smirnov

Oscillation interpretation of the results from the LSND, MiniBooNE and some other experiments requires existence of sterile neutrino with mass ~ 1 eV and mixing with the active neutrinos |U_{\mu 0}|˛ ~(0.02 - 0.04). It has been realized some time ago that existence of such a neutrino affects significantly the fluxes of atmospheric neutrinos in the TeV range which can be tested by the IceCube Neutrino Observatory. In view of the first IceCube data release we have revisited the oscillations of high energy atmospheric neutrinos in the presence of one sterile neutrino. Properties of the oscillation probabilities are studied in details for various mixing schemes. The energy spectra and angular distributions of the \nu_\mu-events have been computed for the simplest \nu_s-mass mixing scheme and confronted with the IceCube data. An illustrative statistical analysis of the present data shows that sterile neutrinos with parameters required by LSND/MiniBooNE can be excluded at about 3\sigma level.

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Blobrana


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Posts: 131433
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RE: IceCube
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IceCube is not the first neutrino observatory to be built by scientists, but it is by far the largest. In 1987, three neutrino detectors, constructed in caverns in Japan, America and the Caucasus, became the first to spot a few handfuls of neutrinos that sprayed out of a supernova called 1987A, which exploded in the Large Magellanic Cloud, a neighbouring galaxy to ours. In Siberia, a Russian-German team has lowered cables carrying 192 light sensors into the clear depths of Lake Baikal, turning 10 megatonnes of water into a neutrino detector. Another neutrino observatory, Antares (Astronomy with a Neutrino Telescope and Abyss Environmental Research), was built off the coast of Toulon in France in Mediterranean waters 2.5km deep. Antares complements IceCube as a northern hemisphere-based observatory.
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Blobrana


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Title: First search for atmospheric and extraterrestrial neutrino-induced cascades with the IceCube detector
Authors: IceCube Collaboration: R. Abbasi, Y. Abdou, T. Abu-Zayyad, J. Adams, J. A. Aguilar, M. Ahlers, K. Andeen, J. Auffenberg, X. Bai, M. Baker, S. W. Barwick, R. Bay, J. L. Bazo Alba, K. Beattie, J. J. Beatty, S. Bechet, J. K. Becker, K.-H. Becker, M. L. Benabderrahmane, S. BenZvi, J. Berdermann, P. Berghaus, D. Berley, E. Bernardini, D. Bertrand, D. Z. Besson, D. Bindig, M. Bissok, E. Blaufuss, J. Blumenthal, D. J. Boersma, C. Bohm, D. Bose, S. B, "oser, O. Botner, J. Braun, A. M. Brown, S. Buitink, M. Carson, D. Chirkin, B. Christy, J. Clem, F. Clevermann, S. Cohen, C. Colnard, D. F. Cowen, M. V. D'Agostino, M. Danninger, J. Daughhetee, J. C. Davis, C. De Clercq, L. Demir, "ors, T. Denger, O. Depaepe, F. Descamps, P. Desiati, G. de Vries-Uiterweerd, T. DeYoung, J. C. D'iaz-Vélez, et al. (205 additional authors not shown)

We report on the first search for atmospheric and for diffuse astrophysical neutrino-induced showers (cascades) in the IceCube detector using 257 days of data collected in the year 2007-2008 with 22 strings active. A total of 14 events with energies above 16 TeV remained after event selections in the diffuse analysis, with an expected total background contribution of 8.3 ±3.6. At 90% confidence we set an upper limit of E^2\Phi_{90%CL}<3.6 x 10^{-7} GeV \cdot cm^{-2} \cdot s^{-1}\cdot sr^{-1}  on the diffuse flux of neutrinos of all flavours in the energy range between 24 TeV and 6.6 PeV assuming that \Phi \propto E^{-2} and that the flavour composition of the \nu_e : \nu_\mu : \nu_\tau flux is 1 : 1 : 1 at the Earth. The atmospheric neutrino analysis was optimised for lower energies. A total of 12 events were observed with energies above 5 TeV. The observed number of events is consistent with the expected background, within the uncertainties.

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Blobrana


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At South Pole, world's most extreme scientific construction project

IceCube, the world's largest observatory ever built to detect the elusive sub-atomic particles called neutrinos, has just been completed in the crystal-clear ice at the South Pole. Trillions of neutrinos stream through the human body at any given moment, but they rarely interact with regular matter, and researchers want to know more about them. The observatory provides an innovative means to investigate the sources and properties of neutrinos, which originate in some of the most spectacular phenomena in the universe.
Over a multi-year construction period, IceCube scientists melted 86 holes -- each 1.5-miles deep -- in the polar ice cap and inserted strings of light sensors into each hole. The water in each of the holes refroze, locking in an array of 5,160 light sensors, all connected to surface computers near the National Science Foundation's Amundsen-Scott South Pole Station.



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Blobrana


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Posts: 131433
Date:
IceCube neutrino observatory
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World's largest neutrino observatory completed at South Pole

Culminating a decade of planning, innovation and testing, construction of the world's largest neutrino observatory was successfully completed today.
The final string of optical sensors was installed on Saturday, Dec. 18, in the IceCube Neutrino Observatory, a massive ice-bound telescope that fills a cubic kilometre of deep Antarctic ice. The main IceCube detector now contains 5,160 optical sensors on 86 strings embedded two kilometres below the National Science Foundation's Amundsen-Scott South Pole Station.
The construction, coordinated by the University of Wisconsin-Madison and underway since 2005, was completed on schedule and within budget.
For IceCube principal investigator and UW-Madison physics professor Francis Halzen, the completion of the detector is the realization of a longtime vision.
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Blobrana


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Posts: 131433
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IceCube Experiment
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Title: Latest results from the IceCube Experiment
Authors: Anthony M Brown, on behalf of the IceCube Collaboration

The IceCube Collaboration is currently building the world's largest neutrino telescope at the South Pole to observe high energy neutrinos from a variety of astrophysical sources. In this paper we review the current status of the IceCube experiment, highlighting some of the results obtained so far.

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