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1.
  • Fenstermacher, M.E., et al. (author)
  • DIII-D research advancing the physics basis for optimizing the tokamak approach to fusion energy
  • 2022
  • In: Nuclear Fusion. - : IOP Publishing. - 0029-5515 .- 1741-4326. ; 62:4
  • Journal article (peer-reviewed)abstract
    • DIII-D physics research addresses critical challenges for the operation of ITER and the next generation of fusion energy devices. This is done through a focus on innovations to provide solutions for high performance long pulse operation, coupled with fundamental plasma physics understanding and model validation, to drive scenario development by integrating high performance core and boundary plasmas. Substantial increases in off-axis current drive efficiency from an innovative top launch system for EC power, and in pressure broadening for Alfven eigenmode control from a co-/counter-I p steerable off-axis neutral beam, all improve the prospects for optimization of future long pulse/steady state high performance tokamak operation. Fundamental studies into the modes that drive the evolution of the pedestal pressure profile and electron vs ion heat flux validate predictive models of pedestal recovery after ELMs. Understanding the physics mechanisms of ELM control and density pumpout by 3D magnetic perturbation fields leads to confident predictions for ITER and future devices. Validated modeling of high-Z shattered pellet injection for disruption mitigation, runaway electron dissipation, and techniques for disruption prediction and avoidance including machine learning, give confidence in handling disruptivity for future devices. For the non-nuclear phase of ITER, two actuators are identified to lower the L-H threshold power in hydrogen plasmas. With this physics understanding and suite of capabilities, a high poloidal beta optimized-core scenario with an internal transport barrier that projects nearly to Q = 10 in ITER at ∼8 MA was coupled to a detached divertor, and a near super H-mode optimized-pedestal scenario with co-I p beam injection was coupled to a radiative divertor. The hybrid core scenario was achieved directly, without the need for anomalous current diffusion, using off-axis current drive actuators. Also, a controller to assess proximity to stability limits and regulate β N in the ITER baseline scenario, based on plasma response to probing 3D fields, was demonstrated. Finally, innovative tokamak operation using a negative triangularity shape showed many attractive features for future pilot plant operation.
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2.
  • Stroth, U., et al. (author)
  • Progress from ASDEX Upgrade experiments in preparing the physics basis of ITER operation and DEMO scenario development
  • 2022
  • In: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 62:4
  • Journal article (peer-reviewed)abstract
    • An overview of recent results obtained at the tokamak ASDEX Upgrade (AUG) is given. A work flow for predictive profile modelling of AUG discharges was established which is able to reproduce experimental H-mode plasma profiles based on engineering parameters only. In the plasma center, theoretical predictions on plasma current redistribution by a dynamo effect were confirmed experimentally. For core transport, the stabilizing effect of fast ion distributions on turbulent transport is shown to be important to explain the core isotope effect and improves the description of hollow low-Z impurity profiles. The L-H power threshold of hydrogen plasmas is not affected by small helium admixtures and it increases continuously from the deuterium to the hydrogen level when the hydrogen concentration is raised from 0 to 100%. One focus of recent campaigns was the search for a fusion relevant integrated plasma scenario without large edge localised modes (ELMs). Results from six different ELM-free confinement regimes are compared with respect to reactor relevance: ELM suppression by magnetic perturbation coils could be attributed to toroidally asymmetric turbulent fluctuations in the vicinity of the separatrix. Stable improved confinement mode plasma phases with a detached inner divertor were obtained using a feedback control of the plasma β. The enhanced D α H-mode regime was extended to higher heating power by feedback controlled radiative cooling with argon. The quasi-coherent exhaust regime was developed into an integrated scenario at high heating power and energy confinement, with a detached divertor and without large ELMs. Small ELMs close to the separatrix lead to peeling-ballooning stability and quasi continuous power exhaust. Helium beam density fluctuation measurements confirm that transport close to the separatrix is important to achieve the different ELM-free regimes. Based on separatrix plasma parameters and interchange-drift-Alfvén turbulence, an analytic model was derived that reproduces the experimentally found important operational boundaries of the density limit and between L- and H-mode confinement. Feedback control for the X-point radiator (XPR) position was established as an important element for divertor detachment control. Stable and detached ELM-free phases with H-mode confinement quality were obtained when the XPR was moved 10 cm above the X-point. Investigations of the plasma in the future flexible snow-flake divertor of AUG by means of first SOLPS-ITER simulations with drifts activated predict beneficial detachment properties and the activation of an additional strike point by the drifts.
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3.
  • Ahrens, J., et al. (author)
  • Calibration and survey of AMANDA with the SPASE detectors
  • 2004
  • In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 522:3, s. 347-359
  • Journal article (peer-reviewed)abstract
    • We report on the analysis of air showers observed in coincidence by the Antarctic Muon and Neutrino detector array (AMANDA-B10) and the South Pole Air Shower Experiment (SPASE-1 and SPASE-2). We discuss the use of coincident events for calibration and survey of the deep AMANDA detector as well as the response of AMANDA to muon bundles. This analysis uses data taken during 1997 when both SPASE-1 and SPASE-2 were in operation to provide a stereo view of AMANDA. © 2003 Elsevier B.V. All rights reserved.
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4.
  • Ahrens, J., et al. (author)
  • Limits to the muon flux from WIMP annihilation in the center of the Earth with the AMANDA detector
  • 2002
  • In: Physical Review D. - : American Physical Society. - 1550-7998 .- 1550-2368. ; 66:3, s. 032006-
  • Journal article (peer-reviewed)abstract
    • A search for nearly vertical up-going muon-neutrinos from neutralino annihilations in the center of the Earth has been performed with the AMANDA-B10 neutrino detector. The data collected in 130.1 days of live time in 1997, ∼10 9 events, have been analyzed for this search. No excess over the expected atmospheric neutrino background has been observed. An upper limit at 90% confidence level has been obtained on the annihilation rate of neutralinos in the center of the Earth, as well as the corresponding muon flux limit, both as a function of the neutralino mass in the range 100 GeV-5000 GeV. © 2002 The American Physical Society.
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5.
  • Ahrens, J., et al. (author)
  • Observation of high energy atmospheric neutrinos with the Antarctic muon and neutrino detector array
  • 2002
  • In: Physical Review D. - : American Physical Society. - 1550-7998 .- 1550-2368. ; 66:1, s. 120051-1200520
  • Journal article (peer-reviewed)abstract
    • The Antarctic muon and neutrino detector array (AMANDA) began collecting data with ten strings in 1997. Results from the first year of operation are presented. Neutrinos coming through the Earth from the Northern Hemisphere are identified by secondary muons moving upward through the array. Cosmic rays in the atmosphere generate a background of downward moving muons, which are about 106 times more abundant than the upward moving muons. Over 130 days of exposure, we observed a total of about 300 neutrino events. In the same period, a background of 1.05 × 109 cosmic ray muon events was recorded. The observed neutrino flux is consistent with atmospheric neutrino predictions. Monte Carlo simulations indicate that 90% of these events lie in the energy range 66 GeV to 3.4 TeV. The observation of atmospheric neutrinos consistent with expectations establishes AMANDA-B10 as a working neutrino telescope.
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6.
  • Ahrens, J., et al. (author)
  • Search for point sources of high-energy neutrinos with AMANDA
  • 2003
  • In: Astrophysical Journal Letters. - : Institute of Physics (IOP). - 2041-8205 .- 0004-637X .- 1538-4357. ; 583:2 I, s. 1040-1057
  • Journal article (peer-reviewed)abstract
    • This paper describes the search for astronomical sources of high-energy neutrinos using the AMANDA-B10 detector, an array of 302 photomultiplier tubes used for the detection of Cerenkov light from upward-traveling neutrino-induced muons, buried deep in ice at the South Pole. The absolute pointing accuracy and angular resolution were studied by using coincident events between the AMANDA detector and two independent telescopes on the surface, the GASP air Cerenkov telescope and the SPASE extensive air shower array. Using data collected from 1997 April to October (130.1 days of live time), a general survey of the northern hemisphere revealed no statistically significant excess of events from any direction. The sensitivity for a flux of muon neutrinos is based on the effective detection area for through-going muons. Averaged over the northern sky, the effective detection area exceeds 10,000 m2 for E μ ≈ 10 TeV. Neutrinos generated in the atmosphere by cosmic-ray interactions were used to verify the predicted performance of the detector. For a source with a differential energy spectrum proportional to Eν -2 and declination larger than +40°, we obtain E2(dNν/dE) ≤ 10-6 GeV cm-2 s-1 for an energy threshold of 10 GeV.
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7.
  • Andres, E., et al. (author)
  • Selected recent results from AMANDA
  • 2001
  • In: ICHEP 2000. Proceedings of the 30th International Conference on High Energy Physics. - : World Scientific. ; , s. 965-968
  • Conference paper (peer-reviewed)abstract
    • We present a selection of results based on data taken in 1997 with the 302-PMT Antarctic Muon and Neutrino Detector Array-B10 ("AMANDA-B10") array. Atmospheric neutrinos created in the northern hemisphere are observed indirectly through their charged current interactions which produce relativistic, Cherenkov-light-emitting upgoing muons in the South Pole ice cap. The reconstructed angular distribution of these events is in good agreement with expectation and demonstrates the viability of this ice-based device as a neutrino telescope. Studies of nearly vertical upgoing muons limit the available parameter space for WIMP dark matter under the assumption that WIMPS are trapped in the earth's gravitational potential well and annihilate with one another near the earth's center.
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8.
  • Wiebusch, C., et al. (author)
  • Results from AMANDA
  • 2002
  • In: Modern Physics Letters A. - : Institution of Electrical Engineers (IEE). - 0217-7323 .- 1793-6632. ; 17:31, s. 2019-2037
  • Journal article (peer-reviewed)abstract
    • The Antarctic Muon and Neutrino Detector Array (AMANDA) is a high-energy neutrino telescope operating at the geographic South Pole. It is a lattice of photomultiplier tubes buried deep in the polar ice. The primary goal of this detector is to discover astrophysical sources of high energy neutrinos. We describe the detector methods of operation and present results from the AMANDA-B10 prototype. We demonstrate the improved sensitivity of the current AMANDA-II detector. We conclude with an outlook to the envisioned sensitivity of the future IceCube detector.
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9.
  • Ahrens, J., et al. (author)
  • Initial results from AMANDA
  • 2001
  • In: 21st Rencontres de Moriond Workshop on Very High-Energy Phenomena in the Universe.
  • Conference paper (peer-reviewed)
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10.
  • Ahrens, J., et al. (author)
  • Limits on diffuse fluxes of high energy extraterrestrial neutrinos with the AMANDA-B10 detector
  • 2003
  • In: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 90:25, s. 2511011-2511015
  • Journal article (peer-reviewed)abstract
    • A report on the limits, which could be placed on diffuse fluxes of high energy extraterrestrial neutrinos, was presented. The incorporation of neutrino oscillations was necessary for interpreting the limits in terms of the flux from a cosmological distributions of sources. The energetic accelerated environments were presented as the sources of high energy extraterrestrial neutrinos.
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11.
  • Ahrens, J., et al. (author)
  • Measurement of the cosmic ray composition at the knee with the SPASE-2/AMANDA-B10 detectors
  • 2004
  • In: Astroparticle physics. - : Elsevier. - 0927-6505 .- 1873-2852. ; 21:6, s. 565-581
  • Journal article (peer-reviewed)abstract
    • The mass composition of high-energy cosmic rays at energies above 1015 eV can provide crucial information for the understanding of their origin. Air showers were measured simultaneously with the SPASE-2 air shower array and the AMANDA-B10 Cherenkov telescope at the South Pole. This combination has the advantage to sample almost all high-energy shower muons and is thus a new approach to the determination of the cosmic ray composition. The change in the cosmic ray mass composition was measured versus existing data from direct measurements at low energies. Our data show an increase of the mean log atomic mass 〈lnA〉 by about 0.8 between 500 TeV and 5 PeV. This trend of an increasing mass through the "knee" region is robust against a variety of systematic effects. © 2004 Elsevier B.V. All rights reserved.
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12.
  • Ahrens, J., et al. (author)
  • Physics and operation of the AMANDA-II high energy neutrino telescope
  • 2002
  • In: Proceedings of the SPIE - The International Society for Optical Engineering 2003. - : Institution of Electrical Engineers (IEE). ; , s. 79-91
  • Conference paper (peer-reviewed)abstract
    • This paper briefly describes the principle of operation and science goals of the AMANDA high energy neutrino telescope located at the South Pole, Antarctica. Results from an earlier phase of the telescope, called AMANDA-B10, demonstrate both reliable operation and the broad astrophysical reach of this device, which includes searches for a variety of sources of ultrahigh energy neutrinos: generic point sources, Gamma-Ray Bursts and diffuse sources. The predicted sensitivity and angular resolution of the telescope were confirmed by studies of atmospheric muon and neutrino backgrounds. We also report on the status of the analysis from AMANDA-II, a larger version with far greater capabilities. At this stage of analysis, details of the ice properties and other systematic uncertainties of the AMANDA-II telescope are under study, but we have made progress toward critical science objectives. In particular, we focus on the search for continuous emission from astrophysical point sources and the search for correlated neutrino emission from Gamma Ray Bursts detected by BATSE before decommissioning in May 2000. During the next two years, we expect to exploit the full potential of AMANDA-II with the installation of a new data acquisition system that records full waveforms from the in-ice optical sensors.
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13.
  • Ahrens, J., et al. (author)
  • Results from the Antarctic muon and nuetrino detector array
  • 2003
  • In: Nuclear physics B, Proceedings supplements. - : Elsevier. - 0920-5632 .- 1873-3832. ; 118, s. 371-379
  • Journal article (peer-reviewed)abstract
    • We show new results from both the older and newer incarnations of AMANDA (AMANDA-B10 and AMANDA-II, respectively). These results demonstrate that AMANDA is a functioning, multipurpose detector with significant physics and astrophysics reach. They include a new higher-statistics measurement of the atmospheric muon neutrino flux and preliminary results from searches for a variety of sources of ultrahigh energy neutrinos: generic point sources, gamma-ray bursters and diffuse sources producing muons in the detector, and diffuse sources producing electromagnetic or hadronic showers in or near the detector.
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14.
  • Ahrens, J., et al. (author)
  • Search for supernova neutrino bursts with the AMANDA detector
  • 2001
  • In: Astroparticle physics. - : Elsevier. - 0927-6505 .- 1873-2852. ; 16:4, s. 345-359
  • Journal article (peer-reviewed)abstract
    • The core collapse of a massive star in the Milky Way will produce a neutrino burst, intense enough to be detected by existing underground detectors. The AMANDA neutrino telescope located deep in the South Pole ice can detect MeV neutrinos by a collective rate increase in all photo-multipliers on top of dark noise. The main source of light comes from positrons produced in the CC reaction of anti-electron neutrinos on free protons ve + p → e+ + n. This paper describes the first supernova search performed on the full sets of data taken during 1997 and 1998 (215 days of live time) with 302 of the detector's optical modules. No candidate events resulted from this search. The performance of the detector is calculated, yielding a 70% coverage of the galaxy with one background fake per year with 90% efficiency for the detector configuration under study. An upper limit at the 90% c.l. on the rate of stellar collapses in the Milky Way is derived, yielding 4.3 events per year. A trigger algorithm is presented and its performance estimated. Possible improvements of the detector hardware are reviewed.
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15.
  • Andrés, E., et al. (author)
  • Observation of high-energy neutrinos using Čerenkov detectors embedded deep in Antarctic ice
  • 2001
  • In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 410:6827, s. 441-443
  • Journal article (peer-reviewed)abstract
    • Neutrinos are elementary particles that carry no electric charge and have little mass. As they interact only weakly with other particles, they can penetrate enormous amounts of matter, and therefore have the potential to directly convey astrophysical information from the edge of the Universe and from deep inside the most cataclysmic high-energy regions. The neutrino's great penetrating power, however, also makes this particle difficult to detect. Underground detectors have observed low-energy neutrinos from the Sun and a nearby supernova2, as well as neutrinos generated in the Earth's atmosphere. But the very low fluxes of high-energy neutrinos from cosmic sources can be observed only by much larger, expandable detectors in, for example, deep water3,4 or ice5. Here we report the detection of upwardly propagating atmospheric neutrinos by the ice-based Antarctic muon and neutrino detector array (AMANDA). These results establish a technology with which to build a kilometre-scale neutrino observatory necessary for astrophysical observations1.
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16.
  • Andrés, E., et al. (author)
  • Recent results from AMANDA
  • 2001
  • In: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 16:1C, s. 1013-1015
  • Journal article (peer-reviewed)abstract
    • We present results based on data taken in 1997 with the 302-PMT Antarctic Muon and Neutrino Detector Array-B10 ("AMANDA-B10") array. Atmospheric neutrinos created in the northern hemisphere are observed indirectly through their charged current interactions which produce relativistic, Cherenkov-light-emitting upgoing muons in the South Pole ice cap. The reconstructed angular distribution of these events is in good agreement with expectation and demonstrates the viability of this ice-based device as a neutrino telescope.
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17.
  • Andres, E., et al. (author)
  • Results from the AMANDA high energy neutrino detector
  • 2000
  • In: Nuclear physics B, Proceedings supplements. - : Elsevier. - 0920-5632 .- 1873-3832. ; 91:1-3, s. 423-430
  • Journal article (peer-reviewed)abstract
    • This paper briefly summarizes the search for astronomical sources of high-energy neutrinos using the AMANDA-B10 detector. The complete data set from 1997 was analyzed. For Eμ > 10 TeV, the detector exceeds 10,000 m2 in effective area between declinations of 25 and 90 degrees. Neutrinos generated in the atmosphere by cosmic ray interactions were used to verify the overall sensitivity of the detector. The absolute pointing accuracy and angular resolution has been confirmed by the analysis of coincident events between the SPASE air shower array and the AMANDA detector. Preliminary flux limits from point source candidates are presented. For declinations larger than +45 degrees, our results compare favorably to existing limits for sources in the Southern sky. We also present the current status of the searches for high energy neutrino emission from diffusely distributed sources, GRBs, and WIMPs from the center of the earth.
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18.
  • Karle, A., et al. (author)
  • Observation of high energy atmospheric neutrinos with AMANDA
  • 2000
  • In: AIP Conference Proceedings. - : American Institute of Physics (AIP). ; , s. 823-827
  • Conference paper (peer-reviewed)abstract
    • In 1997 the Antarctic Muon and Neutrino Detector Array (AMANDA) started operating with 10 strings. In an analysis of data taken during the first year of operation 188 atmospheric neutrino candidates were found. Their zenith angle distribution agrees with expectations based on Monte Carlo simulations. A preliminary upper limit is given on a diffuse flux of high energy neutrinos of astrophysical origin.
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19.
  • Meyer, H.F., et al. (author)
  • Overview of physics studies on ASDEX Upgrade
  • 2019
  • In: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 59:11
  • Research review (peer-reviewed)abstract
    • The ASDEX Upgrade (AUG) programme, jointly run with the EUROfusion MST1 task force, continues to significantly enhance the physics base of ITER and DEMO. Here, the full tungsten wall is a key asset for extrapolating to future devices. The high overall heating power, flexible heating mix and comprehensive diagnostic set allows studies ranging from mimicking the scrape-off-layer and divertor conditions of ITER and DEMO at high density to fully non-inductive operation (q 95 = 5.5, ) at low density. Higher installed electron cyclotron resonance heating power 6 MW, new diagnostics and improved analysis techniques have further enhanced the capabilities of AUG. Stable high-density H-modes with MW m-1 with fully detached strike-points have been demonstrated. The ballooning instability close to the separatrix has been identified as a potential cause leading to the H-mode density limit and is also found to play an important role for the access to small edge-localized modes (ELMs). Density limit disruptions have been successfully avoided using a path-oriented approach to disruption handling and progress has been made in understanding the dissipation and avoidance of runaway electron beams. ELM suppression with resonant magnetic perturbations is now routinely achieved reaching transiently . This gives new insight into the field penetration physics, in particular with respect to plasma flows. Modelling agrees well with plasma response measurements and a helically localised ballooning structure observed prior to the ELM is evidence for the changed edge stability due to the magnetic perturbations. The impact of 3D perturbations on heat load patterns and fast-ion losses have been further elaborated. Progress has also been made in understanding the ELM cycle itself. Here, new fast measurements of and E r allow for inter ELM transport analysis confirming that E r is dominated by the diamagnetic term even for fast timescales. New analysis techniques allow detailed comparison of the ELM crash and are in good agreement with nonlinear MHD modelling. The observation of accelerated ions during the ELM crash can be seen as evidence for the reconnection during the ELM. As type-I ELMs (even mitigated) are likely not a viable operational regime in DEMO studies of 'natural' no ELM regimes have been extended. Stable I-modes up to have been characterised using -feedback. Core physics has been advanced by more detailed characterisation of the turbulence with new measurements such as the eddy tilt angle - measured for the first time - or the cross-phase angle of and fluctuations. These new data put strong constraints on gyro-kinetic turbulence modelling. In addition, carefully executed studies in different main species (H, D and He) and with different heating mixes highlight the importance of the collisional energy exchange for interpreting energy confinement. A new regime with a hollow profile now gives access to regimes mimicking aspects of burning plasma conditions and lead to nonlinear interactions of energetic particle modes despite the sub-Alfvénic beam energy. This will help to validate the fast-ion codes for predicting ITER and DEMO.
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20.
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21.
  • Ahrens, J., et al. (author)
  • Results from AMANDA
  • 2001
  • In: Proceedings, 9th International Workshop, Venice, Italy, March 6-9, 2001. Vol. 1, 2. ; , s. 569-580
  • Conference paper (peer-reviewed)
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22.
  • Ahrens, J., et al. (author)
  • Results from the AMANDA telescope
  • 2003
  • In: Nuclear Physics A. - : Elsevier. - 0375-9474 .- 1873-1554. ; 721, s. C545-C548
  • Journal article (peer-reviewed)abstract
    • We present results from the AMANDA high energy neutrino telescope located at the South Pole. They include measurements of the atmospheric neutrino flux, search for UHE point sources, and diffuse sources producing electromagnetic/hadronic showers at the detector or close to it.
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23.
  • Ahrens, J., et al. (author)
  • Search for neutrino-induced cascades with the AMANDA detector
  • 2003
  • In: Physical Review D. - : American Physical Society (APS). - 1550-7998 .- 1550-2368. ; 67:1, s. 012003-
  • Journal article (peer-reviewed)abstract
    • We report on a search for electromagnetic and/or hadronic showers (cascades) induced by a diffuse flux of neutrinos with energies between 5 TeV and 300 TeV from extraterrestrial sources. Cascades may be produced by matter interactions of all flavors of neutrinos, and contained cascades have better energy resolution and afford better background rejection than throughgoing νμ-induced muons. Data taken in 1997 with the AMANDA detector were searched for events with a high-energy cascadelike signature. The observed events are consistent with expected backgrounds from atmospheric neutrinos and catastrophic energy losses from atmospheric muons. Effective volumes for all flavors of neutrinos, which allow the calculation of limits for any neutrino flux model, are presented. The limit on cascades from a diffuse flux of νe+ νμ + ντ+ ν̄e + ν̄μ+ ν̄τ is E2(dΦ/dE)<9.8×10-6 GeV cm-2 s-1 sr-1, assuming a neutrino flavor flux ratio of 1:1:1 at the detector. The limit on cascades from a diffuse flux of νe+ν̄e is E2(dΦ/dE)<6. 5×10-6 GeV cm-2 s-1 sr-1, independent of the assumed neutrino flavor flux ratio. © 2003 The American Physical Society.
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24.
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25.
  • Bai, X., et al. (author)
  • Status of the Neutrino Telescope AMANDA : Monopoles and WIMPS
  • 2001
  • In: Dark Matter in Astro- and Particle Physics. - Berlin, Heidelberg : Springer. - 9783642626081 ; , s. 699-706
  • Conference paper (peer-reviewed)abstract
    • The neutrino telescope AMANDA has been set up at the geographical South Pole as first step to a neutrino telescope of the scale of one cubic kilometer, which is the canonical size for a detector sensitive to neutrinos from Active Galactic Nuclei (AGN), Gamma Ray Bursts (GRB) and Topological Defects (TD). The location and depth in which the detector is installed is given by the requirement to detect neutrinos by the Cherenkov light produced by their reaction products and to keep the background due to atmospheric muons as small as possible. However, a detector optimized for this purpose is also capable to detect the bright Cherenkov light from relativistic Monopoles and neutrino signals from regions with high gravitational potential, where WIMPS are accumulated and possibly annihilate. Both hypothetical particles might contribute to the amount of dark matter. Therefore here a report about the status of the experiment (autumn 2000) and about the status of the search for these particles with the AMANDA B10 sub-detector is given.
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26.
  • Kowalski, Marek, et al. (author)
  • Physics results from the AMANDA neutrino detector
  • 2001
  • In: Proceedings of Science. - 1824-8039. ; HEP2001
  • Journal article (peer-reviewed)abstract
    • In the winter season of 2000, the AMANDA (Antarctic Muon And NeutrinoDetector Array) detector was completed to its nal state. We report on major physicsresults obtained from the AMANDA-B10 detector, as well as initial results of the fullAMANDA-II detector.
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27.
  • Wischnewski, R., et al. (author)
  • The AMANDA neutrino detector : Status report
  • 2000
  • In: Nuclear physics B, Proceedings supplements. - 0920-5632 .- 1873-3832. ; 85:1-3, s. 141-145
  • Journal article (peer-reviewed)abstract
    • The first stage of the AMANDA High Energy Neutrino Detector at the South Pole, the 302 PMT array AMANDA-B10, is taking data since 1997. We describe results on atmospheric neutrinos, limits on indirect WIMP detection, seasonal muon flux variation, relativistic monopole flux limits, a search for gravitational collapse neutrinos, and a depth scan of the optical ice properties. The next stage 19-string detector AMANDA-II with ∼650 PMTs will be completed in spring 2000.
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28.
  • Ahrens, J., et al. (author)
  • Search for Extraterrestrial Point Sources of Neutrinos with AMANDA-II
  • 2004
  • In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 92:7, s. 711021-711025
  • Journal article (peer-reviewed)abstract
    • The results of a search for point sources of high energy neutrinos in the northern hemisphere were presented using AMANDA-II data collected in the year 2000. The results included the flux limits on several active-galactic-nuclei blazars, microquasars, magnetars, and other candidate neutrino sources. A search for excesses above a random background of cosmic ray induced atmospheric neutrinos and misreconstructed downgoing cosmic-rays muons, which revealed no statistically significant neutrino point sources was also presented. It was shown that AMANDA-II had achieved the sensitivity required to probe known TeV γ-ray sources such as the blazar Markarian 501 in its 1997 flaring state at a level where neutrino and γ-ray fluxes were equal.
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29.
  • Andrés, E. C., et al. (author)
  • The AMANDA neutrino telescope
  • 1999
  • In: Nuclear physics B, Proceedings supplements. - 0920-5632 .- 1873-3832. ; 77:1-3, s. 474-485
  • Journal article (peer-reviewed)abstract
    • With an effective telescope area of order 104 m2 for TeV neutrinos, a threshold near ∼50 GeV and a pointing accuracy of 2.5 degrees per muon track, the AMANDA detector represents the first of a new generation of high energy neutrino telescopes, reaching a scale envisaged over 25 years ago. We describe early results on the calibration of natural deep ice as a particle detector as well as on AMANDA's performance as a neutrino telescope.
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30.
  • Edsjö, Joakim, et al. (author)
  • WIMP searches with AMANDA-B10
  • 2001
  • In: The Identification Of Dark Matter. - : World Scientific. - 9789810246020 ; , s. 499-505
  • Book chapter (other academic/artistic)
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31.
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32.
  • Niessen, Peter, et al. (author)
  • Recent results from the amanda experiment
  • 2003
  • In: Proceedings of 38th Rencontres de Moriond on Electroweak Interactions and Unified Theories 15-22 Mar 2003. Les Arcs, France.
  • Conference paper (peer-reviewed)abstract
    • AMANDA (Antarctic Muon And Neutrino Detector Array) is a neutrino telescope built under the southern polar icecap and its scope is to explore the possibility to detect high energy cosmic neutrinos. This should generate insight into the powerful celestial objects where acceleration mechanisms can bring up to 10 20   eV. We describe the achievements and results from the AMANDA-B10 prototype and the preliminary results from the current AMANDA-II detector which show dramatic increase in sensitivity.
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33.
  • Ahrens, J., et al. (author)
  • Muon track reconstruction and data selection techniques in AMANDA
  • 2004
  • In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 524:1-3, s. 169-194
  • Journal article (peer-reviewed)abstract
    • The Antarctic Muon And Neutrino Detector Array (AMANDA) is a high-energy neutrino telescope operating at the geographic South Pole. It is a lattice of photo-multiplier tubes buried deep in the polar ice between 1500 and 2000 m. The primary goal of this detector is to discover astrophysical sources of high-energy neutrinos. A high-energy muon neutrino coming through the earth from the Northern Hemisphere can be identified by the secondary muon moving upward through the detector. The muon tracks are reconstructed with a maximum likelihood method. It models the arrival times and amplitudes of Cherenkov photons registered by the photo-multipliers. This paper describes the different methods of reconstruction, which have been successfully implemented within AMANDA. Strategies for optimizing the reconstruction performance and rejecting background are presented. For a typical analysis procedure the direction of tracks are reconstructed with about 2° accuracy. © 2004 Elsevier B.V. All rights reserved.
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34.
  • Andres, E., et al. (author)
  • AMANDA : Status, results and future
  • 1999
  • In: Proceedings, 8th International Workshop, Venice, Italy, February 23-26, 1999. Vol. 1, 2. ; , s. 63-79
  • Conference paper (peer-reviewed)abstract
    • We review the status of the AMANDA neutrino telescope. We present resultsobtained from the four-string prototype array AMANDA-B4 and describe themethods of track reconstruction and neutrino event separation. We give also firstresults of the analysis of the 10-string detector AMANDA-B10, in particular onatmospheric neutrinos and the search for magnetic monopoles. We sketch thefuture schedule on the way to a cube kilometer telescope at the South Pole,ICECUBE.
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35.
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36.
  • Wischnewski, R., et al. (author)
  • The AMANDA neutrino detector
  • 1999
  • In: Nuclear physics B, Proceedings supplements. - : Elsevier. - 0920-5632 .- 1873-3832. ; 75:1-2, s. 412-414
  • Journal article (peer-reviewed)abstract
    • The first stage of the AMANDA High Energy Neutrino Detector at the South Pole, the 302 PMT array AMANDA-B with an expected effective area for TeV neutrinos of ∼ 104 m2, has been taking data since 1997. Progress with calibration, investigation of ice properties, as well as muon and neutrino data analysis are described. The next stage 20-string detector AMANDA-II with ∼800 PMTs will be completed in spring 2000.
  •  
37.
  • Andres, E., et al. (author)
  • The AMANDA neutrino telescope : Principle of operation and first results
  • 2000
  • In: Astroparticle physics. - : Elsevier. - 0927-6505 .- 1873-2852. ; 13:1, s. 1-20
  • Journal article (peer-reviewed)abstract
    • AMANDA is a high-energy neutrino telescope presently under construction at the geographical South Pole. In the Antarctic summer 1995/96, an array of 80 optical modules (OMs) arranged on 4 strings (AMANDA-B4) was deployed at depths between 1.5 and 2 km. In this paper we describe the design and performance of the AMANDA-B4 prototype, based on data collected between February and November 1996. Monte Carlo simulations of the detector response to down-going atmospheric muon tracks show that the global behavior of the detector is understood. We describe the data analysis method and present first results on atmospheric muon reconstruction and separation of neutrino candidates. The AMANDA array was upgraded with 216 OMs on 6 new strings in 1996/97 (AMANDA-B10), and 122 additional OMs on 3 strings in 1997/98.
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38.
  • Bay, R. C., et al. (author)
  • The AMANDA neutrino telescope and the indirect search for dark matter : AMANDA Colaboration
  • 1998
  • In: Physics reports. - : Elsevier. - 0370-1573 .- 1873-6270. ; 307:1-4, s. 243-252
  • Journal article (peer-reviewed)abstract
    • With an effective telescope area of order 104m2, a threshold of ~50GeV and a pointing accuracy of 2.5°, the AMANDA detector represents the first of a new generation of high energy neutrino telescopes, reaching a scale envisaged over 25 years ago. We describe its performance, focussing on the capability to detect halo dark matter particles via their annihilation into neutrinos.
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39.
  • Legradi, J. B., et al. (author)
  • An ecotoxicological view on neurotoxicity assessment
  • 2018
  • In: Environmental Sciences Europe. - : Springer. - 2190-4707 .- 2190-4715. ; 30
  • Research review (peer-reviewed)abstract
    • The numbers of potential neurotoxicants in the environment are raising and pose a great risk for humans and the environment. Currently neurotoxicity assessment is mostly performed to predict and prevent harm to human populations. Despite all the efforts invested in the last years in developing novel in vitro or in silico test systems, in vivo tests with rodents are still the only accepted test for neurotoxicity risk assessment in Europe. Despite an increasing number of reports of species showing altered behaviour, neurotoxicity assessment for species in the environment is not required and therefore mostly not performed. Considering the increasing numbers of environmental contaminants with potential neurotoxic potential, eco-neurotoxicity should be also considered in risk assessment. In order to do so novel test systems are needed that can cope with species differences within ecosystems. In the field, online-biomonitoring systems using behavioural information could be used to detect neurotoxic effects and effect-directed analyses could be applied to identify the neurotoxicants causing the effect. Additionally, toxic pressure calculations in combination with mixture modelling could use environmental chemical monitoring data to predict adverse effects and prioritize pollutants for laboratory testing. Cheminformatics based on computational toxicological data from in vitro and in vivo studies could help to identify potential neurotoxicants. An array of in vitro assays covering different modes of action could be applied to screen compounds for neurotoxicity. The selection of in vitro assays could be guided by AOPs relevant for eco-neurotoxicity. In order to be able to perform risk assessment for eco-neurotoxicity, methods need to focus on the most sensitive species in an ecosystem. A test battery using species from different trophic levels might be the best approach. To implement eco-neurotoxicity assessment into European risk assessment, cheminformatics and in vitro screening tests could be used as first approach to identify eco-neurotoxic pollutants. In a second step, a small species test battery could be applied to assess the risks of ecosystems.
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