381. Search for energy dependent patterns in the arrival direction of cosmic rays at the Pierre Auger ObservatoryTobias Winchen, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2015, objavljeni znanstveni prispevek na konferenci Opis: Energy-dependent patterns in the arrival directions of cosmic
rays are expected from deflections in galactic and extragalactic magnetic fields. We report on searches for such
patterns in the data of the surface detector of the Pierre
Auger Observatory at energies above E = 5 EeV in regions
within approximately 15◦ around events with energy E > 60
EeV. No significant patterns are found with this analysis which
can be used to constrain parameters in propagation scenarios.
Ključne besede: ultra-high energy cosmic rays
galactic and extragalactic magnetic fields
magnetic deflection patterns
Pierre Auger Observatory
Objavljeno v RUNG: 02.03.2016; Ogledov: 5362; Prenosov: 228
 Celotno besedilo (1019,52 KB) |
382. Indications of anisotropy at large angular scales in the arrival directions of cosmic rays detected at the Pierre Auger ObservatoryImen Al Samarai, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2015, objavljeni znanstveni prispevek na konferenci Opis: The large-scale distribution of arrival directions of
high-energy cosmic rays carries major clues to understanding
their origin. The Pierre Auger Collaboration have implemented
different analyses to search for dipolar and quadrupolar
anisotropies in different energy ranges spanning four orders
of magnitude. A common phase ≈270◦ of the first harmonic
modulation in right-ascension was found in adjacent energy intervals below 1 EeV, and another common phase ≈100◦
above 4 EeV. A constancy of phase measurements in ordered
energy intervals originating from a genuine anisotropy is
expected to appear with a smaller number of events than those
needed to achieve significant amplitudes. This led us to
design a prescribed test aimed at establishing whether
this consistency in phases is real at 99% CL. The test required
a total independent exposure of 21,000 km2 sr yr. We report on
the status of this prescription. We also report the results of
the search for a dipole anisotropy for cosmic rays with
energies above 4 EeV using events with zenith angles between
60◦ and 80◦. Compared to previous analyses of events with
zenith angles smaller than 60◦, this extension increases
the size of the data set by 30%, and enlarges the fraction of
exposed sky from 71% to 85%. The largest departure from
isotropy is found in the energy range above 8 EeV, with an
amplitude for the first harmonic in right ascension
r1 = (4.4 ± 1.0) × 10[sup]−2, that has a chance probability
P(≥ r1) = 6.4×10[sup]−5, reinforcing the hint previously
reported with vertical events alone.
Ključne besede: high-energy cosmic rays
large-scale distribution
anisotropy studies
Pierre Auger Observatory
Objavljeno v RUNG: 02.03.2016; Ogledov: 5196; Prenosov: 238
Celotno besedilo (862,90 KB) |
383. Arrival directions of the highest-energy cosmic rays detected with the Pierre Auger ObservatoryJulien Aublin, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2015, objavljeni znanstveni prispevek na konferenci Opis: We present the results of a search for small to intermediate
scale anisotropies in the distribution of arrival directions
of ultra-high energy cosmic rays recorded at the Pierre Auger
Observatory. The data set, gathered in ten years of operation,
includes arrival directions with zenith angles up to 80◦,
and is about three times larger than that used in earlier
studies. We update the test based on correlations with active
galactic nuclei (AGNs) from the Véron-Cetty and Véron catalog,
which does not yield a significant indication of anisotropy
with the present data set. We perform a blind search for
localized excess fluxes and for self-clustering of arrival
directions at angular scales up to 30◦ and for different
energy thresholds between 40 EeV and 80 EeV. We also examine
the correlation of arrival directions with relatively nearby galaxies in the 2MRS catalog, AGNs detected by Swift-BAT,
and a sample of radio galaxies with jets and with the
Centaurus A galaxy. None of the searches shows a statistically
significant evidence of anisotropy. The two largest
departures from isotropy that were found have a post-trial
probability ≈ 1.4%. One is for cosmic rays with energy above
58 EeV that arrive within 15◦ of the direction toward
Centaurus A. The other is for arrival directions within 18◦
of Swift-BAT AGNs closer than 130 Mpc and brighter than
10[sup]44 erg/s, with the same energy threshold.
Ključne besede: ultra-high energy cosmic rays
anisotropy studies
active galactic nuclei
Pierre Auger Observatory
Objavljeno v RUNG: 02.03.2016; Ogledov: 5240; Prenosov: 231
Celotno besedilo (1,32 MB) |
384. The flux of ultra-high energy cosmic rays after ten years of operation of the Pierre Auger ObservatoryInés Valiño, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2015, objavljeni znanstveni prispevek na konferenci Opis: The flux of ultra-high energy cosmic rays has been measured
with unprecedented precision at the Pierre Auger Observatory.
We report an update of the all-sky flux of cosmic rays above 3 x 10 [sup] 17 eV obtained by combining four
independent data sets. These measurements are based on data
from the surface detector arrays (divided into two sets according to the shower zenith angle), from a nested, denser,
detector array, and hybrid events measured simultaneously with
both the fluorescence detector and the surface detector array.
The spectral features are presented in detail and the
systematic uncertainties are addressed. The huge amount of data
collected to date, with a total exposure exceeding
50,000 km2 sr yr, together with the wide range of sky observed
(in declination from -90[deg] to 45[deg]) also allow us to
measure the energy spectrum from different regions of the sky.
We present the results of the search for a dependence of the
measured flux on the declination of the incoming directions.
Ključne besede: ultra-high energy cosmic rays
energy spectrum
Pierre Auger Observatory
Objavljeno v RUNG: 02.03.2016; Ogledov: 5737; Prenosov: 226
Celotno besedilo (755,08 KB) |
385. Prototype muon detectors for the AMIGA component of the Pierre Auger ObservatoryA. Aab, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2015, izvirni znanstveni članek Ključne besede: detektor mionov, detektor Čerenkova, AMIGA, P. Auger Observatory
Objavljeno v RUNG: 29.02.2016; Ogledov: 5379; Prenosov: 0
Gradivo ima več datotek! Več... |
386. Nanosecond-level time synchronization of autonomous radio detector stations for extensive air showersA. Aab, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2015, izvirni znanstveni članek Ključne besede: kozmični žarki ekstremnih energij, AERA, GPS, metoda svetilnik
Objavljeno v RUNG: 15.02.2016; Ogledov: 5542; Prenosov: 0
Gradivo ima več datotek! Več... |
387. Optimizacija optičnega nadzora naprave za površinsko montažo elektronskih komponentAndrea Torroni, 2015, diplomsko delo Opis: Namen diplomskega dela je odpravljanje napak na liniji za površinsko montažo elektronskih komponent (SMD). Delo na tej liniji je pokazalo, da so na izdelkih prisotne napake. Te zaradi problematičnega reševanja nepravilnosti zaustavljajo celotni proizvodni proces, za odpravljanje pa se porabi veliko časa. Proces ni več popolnoma avtomatski, kot se za to linijo zahteva. Težave nastajajo predvsem zaradi velikega števila težko predvidljivih vzrokov, ki povzročajo napake. Te lahko nastajajo na vseh napravah linije, glede na nastanek pa jih lahko zberemo v skupine.
S pomočjo nekaterih izdelkov bomo analizirali vse najpogostejše napake. Raziskali bomo realne vzroke za nepravilnosti na vseh napravah na liniji in opisali rešitve za nastale težave. Te bomo z lastnimi izkušnjami tudi utemeljili. S tem delom si bodo lahko operaterji in drugi, ki jih zanima delo na tej liniji, pomagali pri reševanju napak. Opisi reševanja napak naj bi operaterje vodili k hitremu in trajnemu odpravljanju napak.
Ocenili bomo, kolikšne so časovne izgube zaradi nepravilnosti oziroma kolikšen delež časovne optimizacije lahko dosežemo z odpravljanjem določenega števila napak. Cilj je doseči vsaj 5-% časovno izboljšavo na celotni proizvodnji elektronskih vezij. To bo za podjetje pomenilo znaten prihranek. Delo bo prineslo tudi nova zavedanja o pomembnosti odpravljanja napak na liniji.
Ključne besede: elektronika, površinska montaža elementov, avtomatska optična inšpekcija, napake, izboljšave
Objavljeno v RUNG: 05.10.2015; Ogledov: 6759; Prenosov: 290
Celotno besedilo (1,75 MB) |
388. Electrical conductivity in 3,4,9,10-perylenetetracarboxylic dianhidride (PTCDA)Gvido Bratina, Robert Hudej, Marko Zavrtanik, John Nimly Brownell, 2001, izvirni znanstveni članek Opis: The transient photoresponse in 3,4,9,10-perylenetetracarboxylic dianhydride was examined in metal/organic semiconductor/metal heterostructures. Electron-hole pairs are generated within the structure for fields higher than 5 X 10[sup]4 V/cm as a consequence of the exciton dissociation. The mobility of the electrons perpendicular to the molecular layers increases with the applied electric field and saturates for fields higher than 5 X 10[sup]4 V/cm.
Ključne besede: organic semiconductor, thin films, transient photoconductivity
Objavljeno v RUNG: 10.07.2015; Ogledov: 6621; Prenosov: 40
 Povezava na celotno besedilo |
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