Measurements of photoelectron extraction efficiency from CsI into mixtures of Ne with CH4, CF4, CO2 and N2

Experimental measurements of the extraction efficiency f of the UV-induced photoelectrons emitted from a CsI photocathode into gas mixtures of Ne with CH4, CF4, CO2 and N2 are presented; they are compared with model-simulation results. Backscattering of low- energy photoelectrons emitted into noble gas is significantly reduced by the admixture of molecular gases, with direct impact on the effective quantum efficiency. Data are provided on the dependence of f on the type and concentration of the molecular gas in the mixtures and on the electric field.Comment: Presented at MPGD09, CRETE, June 2009; to be published in JINST Proceeding

Trajetorias: a dataset of environmental, epidemiological, and economic indicators for the Brazilian Amazon

The Trajetorias dataset is a harmonized set of environmental, epidemiological, and poverty indicators for all municipalities of the Brazilian Legal Amazon (BLA). This dataset is the result of a scientific synthesis research initiative conducted by scientists from several natural and social sciences fields, consolidating multidisciplinary indicators into a coherent dataset for integrated and interdisciplinary studies of the Brazilian Amazon. The dataset allows the investigation of the association between the Amazonian agrarian systems and their impacts on environmental and epidemiological changes, furthermore enhancing the possibilities for understanding, in a more integrated and consistent way, the scenarios that affect the Amazonian biome and its inhabitants.This work was funded by the Brazilian Research Council (CNPQ MCTIC-SÍNTESE EM BIODIVERSIDADE E SERVIÇOS ECOSSISTÊMICOS-SINBIOSE, process 442357/2019-2). We are grateful to the Synthesis Center on Biodiversity and Ecosystem Services (SinBiose), funded by the Brazilian Research Council, for providing the opportunity for the development of this work. CC, AM, RML, and AD are also grateful to the National Socio-Environmental Synthesis Center (SESYNC) for providing the intellectual environment that stimulated the conception of the present work, as part of the project Development, environmental degradation, and disease spread in the Brazilian Amazon led by Andres Baeza and Mercedes Pascual. We would like to extend a special thanks to Professor Francisco de Assis Costa, from the Pará Federal University (UFPA) for sharing his data on the technological trajectories in the municipalities of the Amazon biome and for his generous discussions and support. We also extend our special thanks to Alexandre Gontijo, Flavio Coelho and Marcelle Chagas, for fruitful discussions during the project.Peer Reviewed"Article signat per 15 autors/es: Ana C. Rorato, Ana Paula Dal’Asta, Raquel Martins Lana, Ricardo B. N. dos Santos, Maria Isabel S. Escada, Camila M. Vogt, Tatiana Campos Neves, Milton Barbosa, Cecilia S. Andreazzi, Izabel C. dos Reis, Danilo A. Fernandes, Mônica da Silva-Nunes, Anielli R. de Souza, Antonio M. V. Monteiro & Claudia T. Codeço "Postprint (published version

[I Submitted a Paper to Acta Médica Portugal. What Happens Now?]

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Development of high-gain gaseous photomultipliers for the visible spectral range

We summarize the development of visible-sensitive gaseous photomultipliers, combining a semitransparent bi-alkali photocathode with a state-of-the-art cascaded electron multiplier. The latter has high photoelectron collection efficiency and a record ion blocking capability. We describe in details the system and methods of photocathode production and characterization, their coupling with the electron multiplier and the gaseous-photomultiplier operation and characterization in a continuous mode. We present results on the properties of laboratory-produced K$_2$CsSb, Cs$_3$Sb and Na$_2$KSb photocathodes and report on their stability and QE in gas; K$_2$CsSb photocathodes yielded QE values in Ar/CH$_4$(95/5) above 30% at wavelengths of 360-400 nm. The novel gaseous photomultiplier yielded stable operation at gains of 10$^5$, in continuous operation mode, in 700 Torr of this gas; its sensitivity to single photons was demonstrated. Other properties are described. The successful detection of visible light with this gas-photomultiplier pave ways towards further development of large-area sealed imaging detectors, of flat geometry, insensitive to magnetic fields, which might have significant impact on light detection in numerous fields.Comment: 22 pages, 12 figures, for submission to JINS

Como a Acta Médica Portuguesa se Adaptou aos Tempos de Pandemia

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Thoughts about the Impact Factor

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