1,550 research outputs found
MARTA: A high-energy cosmic-ray detector concept with high-accuracy muon measurement
A new concept for the direct measurement of muons in air showers is
presented. The concept is based on resistive plate chambers (RPCs), which can
directly measure muons with very good space and time resolution. The muon
detector is shielded by placing it under another detector able to absorb and
measure the electromagnetic component of the showers such as a water-Cherenkov
detector, commonly used in air shower arrays. The combination of the two
detectors in a single, compact detector unit provides a unique measurement that
opens rich possibilities in the study of air showers.Comment: 11 page
Tolerance to the air exposition test of Hoplias lacerdae larvae and juvenile during its initial development
NEXT-100 Technical Design Report (TDR). Executive Summary
In this Technical Design Report (TDR) we describe the NEXT-100 detector that
will search for neutrinoless double beta decay (bbonu) in Xe-136 at the
Laboratorio Subterraneo de Canfranc (LSC), in Spain. The document formalizes
the design presented in our Conceptual Design Report (CDR): an
electroluminescence time projection chamber, with separate readout planes for
calorimetry and tracking, located, respectively, behind cathode and anode. The
detector is designed to hold a maximum of about 150 kg of xenon at 15 bar, or
100 kg at 10 bar. This option builds in the capability to increase the total
isotope mass by 50% while keeping the operating pressure at a manageable level.
The readout plane performing the energy measurement is composed of Hamamatsu
R11410-10 photomultipliers, specially designed for operation in low-background,
xenon-based detectors. Each individual PMT will be isolated from the gas by an
individual, pressure resistant enclosure and will be coupled to the sensitive
volume through a sapphire window. The tracking plane consists in an array of
Hamamatsu S10362-11-050P MPPCs used as tracking pixels. They will be arranged
in square boards holding 64 sensors (8 times8) with a 1-cm pitch. The inner
walls of the TPC, the sapphire windows and the boards holding the MPPCs will be
coated with tetraphenyl butadiene (TPB), a wavelength shifter, to improve the
light collection.Comment: 32 pages, 22 figures, 5 table
Integral Field Spectroscopy of Blue Compact Dwarf Galaxies
We present results on integral-field optical spectroscopy of five luminous
Blue Compact Dwarf galaxies. The data were obtained using the fiber system
INTEGRAL attached at the William Herschel telescope. The galaxies Mrk 370, Mrk
35, Mrk 297, Mrk 314 and III Zw 102 were observed. The central 33"x29" regions
of the galaxies were mapped with a spatial resolution of 2"/spaxel, except for
Mrk 314, in which we observed the central 16"x12" region with a resolution of
0.9"/spaxel$. We use high-resolution optical images to isolate the star-forming
knots in the objects; line ratios, electron densities and oxygen abundances in
each of these regions are computed. We build continuum and emission-line
intensity maps as well as maps of the most relevant line ratios: [OIII]5007\Hb,
[NII]6584\Ha, and Ha\Hb, which allow us to obtain spatial information on the
ionization structure and mechanisms. We also derive the gas velocity field from
the Ha and [OIII]5007 emission lines.
We find that all the five galaxies are in the high end of the metallicity
range of Blue Compact Dwarf galaxies, with oxygen abundances varying from
Z\sun~0.3 to Z\sun~1.5. The objects show HII-like ionization in the whole field
of view, except the outer regions of IIIZw102 whose large [NII]6584/Ha values
suggest the presence of shocks. The five galaxies display inhomogeneous
extinction patterns, and three of them have high Ha/Hb ratios, indicative of a
large dust content; all galaxies display complex, irregular velocity fields in
their inner regions.Comment: 26 pages, 14 figures, 5 tables. Accepted for publication in the Ap
Zoneamento pedoclimático para a cultura do cajueiro (Anacardium occidentale L.) no Estado da Bahia.
bitstream/CNPAT-2010/11182/1/Bd-013.pd
Zoneamento pedoclimatico para a cultura do cajueiro (Anacardium occidentale L.) no Estado da Bahia.
bitstream/CNPAT/7826/1/bd_13.pd
Resolved Photon Processes
We review the present level of knowledge of the hadronic structure of the
photon, as revealed in interactions involving quarks and gluons ``in" the
photon. The concept of photon structure functions is introduced in the
description of deep--inelastic scattering, and existing
parametrizations of the parton densities in the photon are reviewed. We then
turn to hard \gamp\ and \gaga\ collisions, where we treat the production of
jets, heavy quarks, hard (direct) photons, \jpsi\ mesons, and lepton pairs. We
also comment on issues that go beyond perturbation theory, including recent
attempts at a comprehensive description of both hard and soft \gamp\ and \gaga\
interactions. We conclude with a list of open problems.Comment: LaTeX with equation.sty, 85 pages, 29 figures (not included). A
complete PS file of the paper, including figures, can be obtained via
anonymous ftp from
ftp://phenom.physics.wisc.edu/pub/preprints/1995/madph-95-898.ps.
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