1,720,969 research outputs found
Correlation between atmopsheric electric field variations and cosmic rays by the ARGO-YBJ experiment
No full textObserving the effect of the athmospheric electric field inside thunderstroms on the EAS with the ARGO-YBJ experiment
No full textThe strong atmospheric electric fields inside thunderstorms can have a significant effect on the electromagnetic component of cosmic ray air showers. Detecting this effect is particularly important in understanding the relation between the showers and lightning. Some episodes in which intensely changed atmospheric electric field during thunderstorms affect the counting rate of single particle have been recorded by ARGO-YBJ experiment. One of the episodes is discussed carefully, which happened in the morning of July 20, 2009 (Beijing Time). A short duration (∼20 minutes) significant increase of the single particle counting rate with low energy occurs accompanied with strong atmospheric electric field, while a decrease happens in the counting of particles with higher energ
Light-component spectrum of the primary cosmic rays in the multi-TeV region measured by the ARGO-YBJ experiment
No full textThe ARGO-YBJ experiment detects extensive air showers in a wide energy range by means of a full-coverage detector which is in stable data taking in its full configuration since November 2007 at the YBJ International Cosmic Ray Observatory (4300 m a.s.l., Tibet, People’s Republic of China). In this paper the measurement of the light-component spectrum of primary cosmic rays in the energy region (5-200) TeV is reported. The method exploited to analyze the experimental data is based on a Bayesian procedure. The measured intensities of the light component are consistent with the recent CREAM results and higher than that obtained adding the proton and helium spectra reported by the RUNJOB experimen
Early warning for VHE gamma-ray flares with the ARGO-YBJ detector
No full textDetecting and monitoring emissions from flaring gamma-ray sources in the very-high-energy (VHE, > 100 GeV) band is a very important topic in gamma-ray astronomy. The ARGO-YBJ detector is characterized by a high duty cycle and a wide field of view. Therefore, it is particularly capable of detecting flares from extragalactic objects. Based on fast reconstruction and analysis, real-time monitoring of 33 selected VHE extragalactic sources is implemented. Flares exceeding a specific threshold are reported timely, hence enabling the follow-up observation of these objects using more sensitive detectors, such as Cherenkov telescop
222Rn daughters influence on scaler mode of the ARGO-YBJ detector
No full textThe ARGO-YBJ experiment is a full coverage air shower array; its lowest energy threshold is reached using the "scaler mode technique". Working in this mode, the signals generated by any particle hitting each cluster are put in coincidence every 150 ns and read by four independent scaler channels, giving the counting rates of multiplicity ≥1, ≥2, ≥3 and ≥4 (C1, C2, C3 and C4, respectively). The study of these counting rates pointed out a different behaviour of C1 respect to C2, C3 and C4, suggesting that C1 is detecting not only cosmic rays. This work shows that the radon (222Rn) gamma emitter daughters present in the ARGO-YBJ building air are contributing to C1 counts at the level of 1 Hz each Bq/m3 of radon. The uncertainty about this contribution is great, because of the high variability of 222Rn concentration and the building ventilation. The radon monitoring will allow the C1 correction improving the sensitivity of the ARGO-YBJ experiment at its lowest energy threshold
Study of natural radioactivity influence on the ARGO-YBJ detector
No full textARGO-YBJ is an extensive air shower detector located at the Yangbajing Cosmic Ray Laboratory (4300 m a.s.l., Tibet, P.R. China). It is made by a single layer of Resistive Plate Chambers organized into 153 units called "clusters" (7.6 x 5.7 m(2) of area). The lowest energy threshold of the experiment (about 1 GeV) is obtained in the "scaler operation mode"
Correlation between cosmic ray flux and electric atmospheric field variations with the ARGO-YBJ experiment
No full textARGO-YBJ is an extensive air shower detector located at Yangbajing (Tibet, China) at 4300 m a.s.l..
It is made by a full coverage carpet plus a guard ring (total surface ∼6700 m2
) of Resistive Plate Chambers
grouped into 153 units called clusters. The experiment has two different operation modes: in scaler mode the
detector records the number of events with particle multiplicity ≥1, ≥2, ≥3, ≥4 over each cluster (reaching
an energy threshold of a few GeV), while in shower mode the coordinates and arrival time of each particle are
recorded for a complete shower reconstruction at an energy threshold of a few hundred GeV.
In this paper the scaler mode counting rate variations during thunderstorms in the summer 2011 and 2012 have
been studied. A strong correlation between the counting rate variations and the atmospheric electric field strength
has been found
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
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