1,721,014 research outputs found
ICARUS and status of liquid argon technology
No full textICARUS T600 is the largest liquid Argon Time Projection Chamber (LAr TPC) detector ever realized. It operates underground at the LNGS laboratory in Gran Sasso. It has been smoothly running since summer 2010, collecting data with the CNGS (Cern to Gran Sasso) beam and with cosmic particles. Liquid Argon TPCs are indeed 'electronic bubble chambers', providing a completely uniform imaging calorimetry with unprecedented accuracy on such massive volumes. ICARUS T600 is internationally considered as a milestone towards the realization of the next generation of massive detectors (tens of ktons) for neutrino and rare event physics. Results will be presented on the data collected so far with the detector
Status of the ICARUS T600 detector at the LNGS
No full textThe installation of the ICARUS T600 Liquid Argon TPC detector at the INFN (Istituto Nazionale di Fisica Nucleare) LNGS underground Laboratory (Assergi, Italy) is almost completed and its commissioning is forthcoming: the detector, the cryogenic plant and the data acquisition are now essentially ready. The main phases of the installation of the T600 plant will be resumed and the first tests on the inner detector constituents will be presented. Finally, the next steps needed to bring the T600 apparatus to the full operation in view of the physics run with the CNGS neutrino beam and the cosmic neutrinos will be explained
Some recent results from the ICARUS experiment
No full textAbstractICARUS is the largest liquid Argon TPC detector ever built (∼ 600 ton LAr mass). It was smoothly operated underground at the LNGS laboratory in Gran Sasso since summer 2010, up to June 2013, collecting data with the CNGS beam and with cosmics. ICARUS is internationally considered as a milestone towards the realization of next generation of massive detectors (∼ tens of ktons) for neutrino and rare event physics. It permits, as a unique feature, the unambiguous identification of νe events. In particular an update of the experimental search for a νe signal in the LSND anomaly region in the CNGS beam will be here presented with the full statistics. The published result strongly limits the window of opened options for the LSND anomaly, reducing the remaining effect to a narrow region centered around (Δm2,sin2(2θ))=(0.5 eV2,0.005) where there is an overall agreement (90% CL) between the present ICARUS limit, the published limits of KARMEN and the published positive signals of LSND and MiniBooNE collaborations. Moreover, new results will be shown concerning the analysis of a CNGS beam-related stopping muon sample with the purpose of the momentum reconstruction through multiple Coulomb scattering. Finally, the most recent result on the Argon purity analysis will be presented, which allowed to reach impressive results in terms of Argon purity and a free electron lifetime exceeding 12 ms, corresponding to about 25 parts per trillion of O2-equivalent contamination: a milestone for any future project involving LAr-TPCs and the development of higher detector mass scales
Noble-gas liquid detectors: measurement of light diffusion and reflectivity on commonly adopted inner surface materials
No full textNoble-gas liquids, such as xenon and argon, have been recently proposed as Vacuum Ultra Violet (VUV) light scintillators in some experiments dedicated to neutrino physics and dark matter research. Fundamental parameters for the photon detection are the diffusion coefficient and the reflectivity of the materials that surround the active volume of the apparatus. We carried out a investigation on the most commonly used materials at the scintillation wavelength λ ∼ 172 nm (close to the liquid xenon wavelength). The measurement has been performed at various incident angles by means of a collimated VUV source. The experimental set-up and the results obtained at room temperature with stainless steel, aluminum, peek and teflon targets are presented
Measurement of photocathode spectral response at cryogenic temperature
No full textNoble-gas liquids, such as xenon and argon, have been recently proposed as light scintillators in some experiments dedicated to neutrino physics and dark matter research. These experiments need the use of photomultiplier tubes directly immersed in the liquid phase and operating at cryogenic temperatures. We carried out an investigation about the spectral response and its variation from room to cryogenic temperature for two different kind of cryogenic photocathodes manufactured by Electron Tubes Ltd. and Hamamatsu Photonics K.K. Measurements were carried out by means of a xenon continuous lamp and a UV-VIS monocromator which allows the analysis from 300 to 700 nm with 5 nm resolution. Cryogenic tests were made at the liquid nitrogen temperature (77 K)
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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