905 research outputs found
Characterization of FBK small-pitch 3D diodes after neutron irradiation up to 3.5x10**16 neq cm**-2
We report on the characterization by a position resolved laser system of
small-pitch 3D diodes irradiated with neutrons up to an extremely high fluence
of 3.5x10**16 neq cm**-2. We show that very high values of signal efficiency
are obtained, in good agreement with the geometrical expectation based on the
small values of the inter-electrode spacings, and also boosted by charge
multiplication effects at high voltage. These results confirm the very high
radiation tolerance of small-pitch 3D sensors well beyond the maximum fluences
expected at the High Luminosity LHC.Comment: 10 pages, 7 figures, submitted to Proceedings of IWORID 2018 on JINS
Progress in 3D Silicon Radiation Detectors
In the past few years, there has been an increasing interest toward 3D silicon radiation detectors. Owing to their unique architecture, 3D detectors provide a remarkable radiation hardness at relatively low bias voltage (hence low power dissipation), that makes them the most appealing solution for use in the innermost layers of tracking detectors in High Energy Physics (HEP) experiments. Besides this primary application, the use of 3D sensor technology has been extended also to other fields, like thermal neutron detection and microdosimetry for proton and ion therapy. In this paper, we will review the state of the art and on going efforts in 3D detectors, covering the main design and technological issues, as well as selected results from the experimental characterization and TCAD simulation.publishedVersio
Development of New 3D Pixel Sensors for Phase 2 Upgrades at LHC
We report on the development of new 3D pixel sensors for the Phase 2 Upgrades
at the High-Luminosity LHC (HL-LHC). To cope with the requirements of increased
pixel granularity (e.g., 50x50 or 25x100 um2 pixel size) and extreme radiation
hardness (up to a fluence of 2e16 neq cm-2), thinner 3D sensors (~100 um) with
electrodes having narrower size (~ 5 um) and reduced spacing (~ 30 um) are
considered. The paper covers TCAD simulations, as well as technological and
design aspects relevant to the first batch of these 3D sensors, that is
currently being fabricated at FBK on 6-inch wafers.Comment: 4 pages, 8 figures, 2015 IEEE Nuclear Science Symposium and Medical
Imaging Conferenc
Mapeamento da soja por meio de técnicas de sensoriamento remoto nos municípios de Lages e Capão Alto - estado de Santa Catarina
TCC (graduação) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Agronomia.O objetivo deste trabalho foi mapear a área plantada de soja nos municípios de Lages e
Capão Alto através de técnicas de sensoriamento remoto nas safras 2012/2013 e 2020/2021.
Foram utilizadas imagens dos satélites Landsat-7, Landsat-8 e Sentinel-2 e a identificação
das áreas foi feita através de interpretação visual das imagens multitemporais submetidas a
uma composição RGB que permitiu que a soja se destacasse em meio aos demais alvos da
cena. Os resultados obtidos neste trabalho foram comparados com dados de monitoramento
de safra realizado pela Epagri/Cepa, apresentando valores acima dos dados oficiais. Através
do mapeamento, foi constatado um aumento de área de 13 mil ha entre as safras 2012/2013
e 2020/2021. O cruzamento das áreas de expansão de soja com classes de uso do solo
mostraram que a conversão tem ocorrido, principalmente, sobre campos nativos. Além
disso, o confronto com dados de altitude e declividade indicam que a expansão tem migrado
para áreas mais altas e se mantido na classe de relevo suave-ondulada. O uso de técnicas
de sensoriamento remoto permitiu o mapeamento das áreas de soja, através de uma
metodologia possível de ser aplicada também em outros locais de estudo.The main of this study was to map the soybean crop area in the municipalities of Lages and
Capão Alto through remote sensing techniques in the 2012/2013 and 2020/2021 harvests.
Landsat-7, Landsat-8 and Sentinel-2 satellite images were used and the identification of the
areas was made by visual interpretation of the multitemporal images submitted to a RGB
composition that allowed the soybean to stand out among the other targets in the scene. The
results obtained in this study were compared with crop monitoring data carried out by
Epagri/Cepa, presenting values above the official data. Through the mapping, an increase
in area of 13 thousand ha was found between the 2012/2013 and 2020/2021 harvests. The
crossing of soybean expansion areas with land use classes showed that conversion has
occurred mainly over native fields. In addition, the comparison with altitude and slope data
indicates that the expansion has migrated to higher areas and remained in the smooth-wavy
class. The use of remote sensing techniques allowed the mapping of soybean crop areas,
through a methodology that could also be applied in other study areas.
Keywords: remote sensing, soybean, geotechnologies, agricultural monitorin
Mapeamento da soja por meio de técnicas de sensoriamento remoto nos municípios de Lages e Capão Alto - Estado de Santa Catarina
TCC (graduação) - Universidade Federal de Santa Catarina. Centro de Ciências Agrárias. Curso de Agronomia.O objetivo deste trabalho foi mapear a área plantada de soja nos municípios de Lages e
Capão Alto através de técnicas de sensoriamento remoto nas safras 2012/2013 e 2020/2021.
Foram utilizadas imagens dos satélites Landsat-7, Landsat-8 e Sentinel-2 e a identificação
das áreas foi feita através de interpretação visual das imagens multitemporais submetidas a
uma composição RGB que permitiu que a soja se destacasse em meio aos demais alvos da
cena. Os resultados obtidos neste trabalho foram comparados com dados de monitoramento
de safra realizado pela Epagri/Cepa, apresentando valores acima dos dados oficiais. Através
do mapeamento, foi constatado um aumento de área de 13 mil ha entre as safras 2012/2013
e 2020/2021. O cruzamento das áreas de expansão de soja com classes de uso do solo
mostraram que a conversão tem ocorrido, principalmente, sobre campos nativos. Além
disso, o confronto com dados de altitude e declividade indicam que a expansão tem migrado
para áreas mais altas e se mantido na classe de relevo suave-ondulada. O uso de técnicas
de sensoriamento remoto permitiu o mapeamento das áreas de soja, através de uma
metodologia possível de ser aplicada também em outros locais de estudo.The main of this study was to map the soybean crop area in the municipalities of Lages and
Capão Alto through remote sensing techniques in the 2012/2013 and 2020/2021 harvests.
Landsat-7, Landsat-8 and Sentinel-2 satellite images were used and the identification of the
areas was made by visual interpretation of the multitemporal images submitted to a RGB
composition that allowed the soybean to stand out among the other targets in the scene. The
results obtained in this study were compared with crop monitoring data carried out by
Epagri/Cepa, presenting values above the official data. Through the mapping, an increase
in area of 13 thousand ha was found between the 2012/2013 and 2020/2021 harvests. The
crossing of soybean expansion areas with land use classes showed that conversion has
occurred mainly over native fields. In addition, the comparison with altitude and slope data
indicates that the expansion has migrated to higher areas and remained in the smooth-wavy
class. The use of remote sensing techniques allowed the mapping of soybean crop areas,
through a methodology that could also be applied in other study areas
Agricultura familiar agroecológica e os desafios da extensão rural no Oeste Catarinense
TCC (graduação) - Universidade Federal de Santa Catarina. Centro de Ciências Agrárias. Curso de Agronomia.A agricultura familiar na mesorregião Oeste Catarinense está profundamente relacionada com a formação social e econômica daquele território. No contexto atual, com a intensa urbanização e modernização de técnicas agrícolas, grande é o número de agricultores sofrendo com a exclusão social. A agroecologia se apresenta como uma oportunidade valiosa de geração de renda, bem-estar e sustentabilidade, possível de ser praticada em pequenas propriedades e coerente com as demandas dos consumidores. No entanto, para que os agricultores sejam bem sucedidos nessa empreitada, se faz necessário que suas demandas em relação à extensão rural agroecológica sejam atendidas. Estudos apontam para uma insatisfação dos agricultores familiares em relação a essa atuação. O objetivo desse estudo foi o de identificar os fatores que estão restringindo esse acesso à extensão rural por parte dos agricultores familiares orientados por princípios agroecológicos da região oeste do estado. Para elucidar essa questão além de uma revisão bibliográfica sobre as temáticas envolvidas, foram realizadas entrevistas semi-estruturadas com agricultores familiares orientados por princípios agroecológicos e também questionários com extensionistas rurais que atuam na área. A análise de conteúdo das entrevistas foi fundamentada na seleção de categorias, características e indicadores significativos dos conceitos vinculados com o objeto de estudo. Concluiu-se que o modelo de extensão rural demandado pelas famílias de agricultores é composto de dez principais demandas que, em geral, não estão sendo atendidas devido ao número inadequado de profissionais disponíveis, a falta de articulação entre as esferas federais, estaduais e locais envolvidas com extensão a rural, e a falta de apoio das lideranças dessas mesmas esferas ao projeto agroecológico
TCAD Analysis of Leakage Current and Breakdown Voltage in Small Pitch 3D Pixel Sensors
Small-pitch 3D pixel sensors have been developed to equip the innermost layers of the ATLAS and CMS tracker upgrades at the High Luminosity LHC. They feature 50 × 50 and 25 × 100 μm2 geometries and are fabricated on p-type Si-Si Direct Wafer Bonded substrates of 150 μm active thickness with a single-sided process. Due to the short inter-electrode distance, charge trapping effects are strongly mitigated, making these sensors extremely radiation hard. Results from beam test measurements of 3D pixel modules irradiated at large fluences (1016neq/cm2) indeed demonstrated high efficiency at maximum bias voltages of the order of 150 V. However, the downscaled sensor structure also lends itself to high electric fields as the bias voltage is increased, meaning that premature electrical breakdown due to impact ionization is a concern. In this study, TCAD simulations incorporating advanced surface and bulk damage models are used to investigate the leakage current and breakdown behavior of these sensors. Simulations are compared with measured characteristics of 3D diodes irradiated with neutrons at fluences up to 1.5 × 1016neq/cm2. The dependence of the breakdown voltage on geometrical parameters (e.g., the n+ column radius and the gap between the n+ column tip and the highly doped p++ handle wafer) is also discussed for optimization purposes
First Production of New Thin 3D Sensors for HL-LHC at FBK
Owing to their intrinsic (geometry dependent) radiation hardness, 3D pixel
sensors are promising candidates for the innermost tracking layers of the
forthcoming experiment upgrades at the Phase 2 High-Luminosity LHC (HL-LHC). To
this purpose, extreme radiation hardness up to the expected maximum fluence of
2e16 neq.cm-2 must come along with several technological improvements in a new
generation of 3D pixels, i.e., increased pixel granularity (50x50 or 25x100 um2
cell size), thinner active region (~100 um), narrower columnar electrodes (~5
um diameter) with reduced inter-electrode spacing (~30 um), and very slim edges
(~100 um). The fabrication of the first batch of these new 3D sensors was
recently completed at FBK on Si-Si direct wafer bonded 6-inch substrates.
Initial electrical test results, performed at wafer level on sensors and test
structures, highlighted very promising performance, in good agreement with TCAD
simulations: low leakage current (<1 pA/column), intrinsic breakdown voltage of
more than 150 V, capacitance of about 50 fF/column, thus assessing the validity
of the design approach. A large variety of pixel sensors compatible with both
existing (e.g., ATLAS FEI4 and CMS PSI46) and future (e.g., RD53) read-out
chips were fabricated, that were also electrically tested on wafer using a
temporary metal layer patterned as strips shorting rows of pixels together.
This allowed a statistically significant distribution of the relevant
electrical quantities to be obtained, thus gaining insight into the impact of
process-induced defects. A few 3D strip test structures were irradiated with
X-rays, showing inter-strip resistance of at least several GOhm even after 50
Mrad(Si) dose, thus proving the p-spray robustness. We present the most
important design and technological aspects, and results obtained from the
initial investigations.Comment: 8 pages, 7 figures, 2016 IWORI
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