Departamento de Física
URI permanente desta comunidadehttps://repositorio.fei.edu.br/handle/FEI/785
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12 resultados
Resultados da Pesquisa
- The NUMEN project @ LNS: Status and perspectives(2019-09-03) CAPPUZZELLO, F.; AGODI, C.; ACOSTA, L.; AMADOR-VALENZUELA, P.; AUERBACH, N.; BAREA, J.; BELLONE, J. I.; BELMONT, D.; BIJKER, R.; BONANNO, D.; BORELLO-LEWIN, T.; BOZTOSUN, I.; BRANCHINA, V.; BRASOLI, S.; BRISCHETTO, G.; BRUNASSO, O.; BURRELLO, S.; CALABRESE, S.; CALABRETTA, L.; CALVO, D.; CAPIROSSI, V.; CARBONE, D.; CAVALLARO, M.; CHEN, R.; CIRALDO, I.; LOMELI, E. R. C.; COLONNA, M.; D'AGOSTINO, G.; DJAPO, H.; DE GERONIMO, G.; DELAUNAY, F.; DESHMUKN, N.; DE FARIA, P. N.; ESPEJEL, R.; FERRARESI, C.; FERREIRA, J. L.; FERRETTI, J.; FINOCCHIARO, P.; FIRAT, S.; FISICHELLA, M.; FLORES, A.; FOTI, A.; GALLO, G.; GARCIA-TECOCOATZI, H.; GONGORA, B.; HACISALIHOGLU, A.; HAZAR, S.; HUERTA, A.; KOTILA, J.; KUCUK, Y.; IAZZI, F.; LANZALONE, G.; LA VIA, F.; LAY, J. A.; LENSKE, H.; LINARES, R.; LONGHITANO, F.; LO PRESTI, D.; LUBIAN, J.; MA, J.; MARIN-LAMBARRI, D.; MARTINEZ, S.; MAS, J.; MEDINA, N. H.; MENDES, D. R.; MEREU, P.; MORALLES, M.; OLIVEIRA, J. R. B.; ORDONEZ, C.; PAKOU, A.; PANDOLA, L.; PETRASCU, H.; PIETRALLA, N.; PINNA, F.; REITO, S.; REZA, G.; RIES, P.; RIFUGGIATO, D.; RODRIGUES, M. R. D.; RUSSO, A. D.; RUSSO, G.; SANDOVAL, S.; SANTOPINTO, E.; Roberto Santos; SGOUROS, O.; Marcilei Aparecida Guazzelli; SOLAKCI, S. O.; SOULIOTIS, G.; SOUKERA, V.; SPATAFORA, A.; TORRESI, D.; TUDISCO, S.; VSEVOLODOVNA, R. I. M.; VARGAS, H.; VEGA, G.; WANG, J. S.; WERNER, V.; YANG, Y. Y.; YILDIRIN, A.; ZAGATTO, V. A. B.© 2019 Author(s).The NUMEN project aims at accessing experimentally driven information on Nuclear Matrix Elements (NME) involved in the half-life of the neutrinoless double beta decay (0υββ), by high-accuracy measurements of the cross sections of Heavy Ion (HI) induced Double Charge Exchange (DCE) reactions. Particular interest is given to the (18O,18Ne) and (20Ne,20O) reactions as tools for β+ β+ and β-β- decays, respectively. First evidence about the possibility to get quantitative information about NME from experiments is found for both kind of reactions. In the experiments, performed at INFN - Laboratory Nazionali del Sud (LNS) in Catania, the beams are accelerated by the Superconducting Cyclotron (CS) and the reaction products are detected by the MAGNEX magnetic spectrometer. The measured cross sections are challengingly low, limiting the present exploration to few selected isotopes of interest in the context of typically low-yield experimental runs. A major upgrade of the LNS facility is foreseen in order to significantly increase the experimental yield, thus making feasible a systematic study of all the cases of interest. Frontiers technologies are going to be developed, to this purpose, for the accelerator and the detection systems. In parallel, advanced theoretical models are developed aiming at extracting the nuclear structure information from the measured cross sections.
- The NUMEN project @ LNS: Status and perspectives(2019-09-03) CAPPUZZELLO, F.; AGODI, C.; ACOSTA, L.; ALTANA, C.; AMADOR-VALENZUELA, P.; AUERBACH, N.; BAREA, J.; BELLONE, J.; BIJKER, R.; BONANNO, D.; BORELLO-LEWIN, T.; BOZTOSUN, I.; BRANCHINA, V.; BRASOLIN, S.; BRISCHETTO, G.; BRUNASSO, O.; BURRELLO, S.; CALABRESE, S.; CALABRETTA, L.; CALVO, D.; CAPIROSSI, V.; CARBONE, D.; CAVALLARO, M.; GARCIA,L. E. C.; LOMELI, E. R. C.; CHEN, R.; CIRALDO, I.; COLONNA, M.; D'AGOSTINO, G.; DELAUNAY, F.; DESHMUKH, N.; DJAPO, H.; DE GERONIMO, G.; DE LOS RIOS, K.; FERRARESI, C.; FERREIRA, J. L.; FERRETTI, J.; FINOCCHIARO, P.; FIRAT, S.; FISICHELLA, M.; FOTI, A.; GALLO, G.; GARCIA-TECOCOATZI, H.; HACISALIHOGLU, A.; HUERTA-HERNANDEZ, A.; KOTILA, Z. J.; KUCUK, Y.; IAZZI, F.; LANZALONE, G.; LAY, J. A.; LA FAUCI, L.; LA VIA, F.; LENSKE, H.; LINARES, R.; LO PRESTI, D.; LUBIAN, J.; MA. J.; MARIN-LAMBARRI, D.; RUIZ, J. M.; MEDINA, N. H.; MENDES, D. R.; MEREU, P.; MORALLES, M.; NERI, L.; OLIVEIRA, J. R. B.; PAKOU, A.; PANDOLA, L.; PETRASCU, H.; PIETRALLA, N.; PINNA, F.; REITO, S.; RIES, P.; RODRIGUES, M. R. D.; RUSSO, A. D.; RUSSO, G.; SANTOPINTO, E.; Roberto Santos; SERBINA, L.; SGOUROS, O.; Marcilei Aparecida Guazzelli; SOLAKCL, S. O.; SOULIOTIS, G.; SOUKERAS, V.; SPATAFORA, A.; TORRESI, D.; TUDISCO, S.; HERNANDEZ, H. V.; VSEVOLODOVNA, R. I. M.; WANG, J. S.; WERNER, V.; YANG, Y. Y.; YILDIRIN, A.; ZAGATTO, V. A. B.© 2019 Author(s).The NUMEN project aims at accessing experimentally driven information on Nuclear Matrix Elements (NME) involved in the half-life of the neutrinoless double beta decay (0νββ), by high-accuracy measurements of Heavy Ion (HI) induced Double Charge Exchange (DCE) reaction cross sections. In particular, the (18O,18Ne) and (20Ne,20O) reactions are used as tools for β+β+ and β-β- decays, respectively. In the experiments, performed at INFN - Laboratory Nazionali del Sud (LNS) in Catania, the beams are accelerated by the Superconducting Cyclotron (CS) and the reaction ejectiles are detected the MAGNEX magnetic spectrometer. The measured cross sections are challengingly low (a few nb), being the total reaction cross section much larger (a few b), thus a high sensitivity and a large rejection capability are demanded to the experimental set-up. This limits the present exploration to few selected isotopes of interest in the context of typically low-yield experimental runs. A major upgrade of the LNS facility is foreseen in order to increase the experimental yield of at least two orders of magnitude, still keeping the high sensitivity of the present set-up, making it feasible a systematic study of all the cases of interest. Frontiers technologies are going to be developed, to this purpose, for the accelerator and the detection systems. In parallel, advanced theoretical models are being developed in order to extract the nuclear structure information from the measured cross sections.
- New experimental campaign of NUMEN project(2019-09-05) AGODI, C.; CAPPUZZELLO, F.; ACOSTA, L.; AMADOR-VALENZUELA, P.; AUERBACH, N.; BAREA, J.; BELLONE, J. I.; BELMONT, D.; BIJKER, R.; BONANNO, D.; BORELLO-LEWIN, T.; BOSTOZUN, I.; BRANCHINA, V.; BRASOLIN, S.; BRISCHETTO, G.; BRUNASSO, O.; BURRELLO, S.; CALABRESE, S.; CALABRETTA, L.; CALVO, D.; CAPIROSSI, V.; CARBONE, D.; CAVALLARO, M.; CHEN, R.; CIRALDO, I.; LOMELI, E. R. C.; COLONNA, M.; D' AGOSTINO, G.; DJAPO, H.; DE GERONIMO, G.; DELAUNAY, F.; DESHMUKH, N.; DE FARIA, P. N.; ESPEJEL, R.; FERRARESI, C.; FERREIRA, J. L.; FERRETTI, J.; FINOCCHIARO, P.; FIRAT, S.; FISICHELLA M.; FLORES A.; FOTI A.; GALLO G.; GARCIA-TECOCOATZI H.; GONGORA B.; HACISALIHOGLU A.; HAZAR S.; HUERTA A.; KOTIJA J.; KUCUK Y.; IAZZI F.; LANZALONE G.; LA VIA F.; LAY J. A.; LENSKE H.; LINARES R.; LONGHITANO F.; LO PRESTI D.; LUBIAN J.; MA J.; MARIN-LAMBARRI D.; MATINEZ S.; MEDINA N. H.; MENDES D. R.; MEREU P.; MORALLES M.; OLIVEIRA J. R. B.; ORDONEZ C.; PAKOU A.; PANDOLA L.; PETRASCU H.; PIETRALLA N.; PINNA F.; REITO S.; REZA G.; RIES P.; RIFUGGIATO D.; RODRIGUES M. R. D.; RUSSO A. D.; RUSSO G.; SANDOVAL S.; SANTOPINTO E.; Roberto Santos; SGOUROS O.; Marcilei Aparecida Guazzelli; SOLAKCI S. O.; SOULIOTIS G.; SOUKERAS V.; SPATAFORA A.; TORRESI D.; TUDISCO S.; VSEVOLODOVNA R. I. M.; VARGA H.; VEGA G.; WANG J. S.; WERNER V.; YANG Y. Y.; YILDIRIN A.; ZAGATTO V. A. B.© 2019 Author(s).The NUMEN main goal is the extraction from measured cross-sections of "data-driven" information on Nuclear Matrix Elements for all the systems candidate for 0νββ. The idea is to use as experimental tool Heavy Ions -Double Charge Exchange (HI-DCE) reactions. Crucial for the experimental challanges is the INFN Laboratori Nazionali del Sud (LNS) facility, made by the Superconducting Cyclotron (CS) and the MAGNEX magnetic spectrometer. The experimental measurements of HI-DCE reactions present a number of challenging aspects, since they are characterized by very low cross sections. Here it is reported the new experimental campaign of NUMEN Project.
- Absorbed gamma-ray doses due to natural radionuclides in building materials(2010-09-05) AGUIAR, V. A. P.; MEDINA, N. H.; MOREIRA, R. H.; Marcilei Aparecida GuazzelliThis work is devoted to the application of high-resolution gamma-ray spectrometry in the study of the effective dose coming from naturally occurring radionuclides, namely 40K, 232Th and 238U, present in building materials such as sand, cement, and granitic gravel. Four models were applied to estimate the effective dose and the hazard indices. The maximum estimated effective dose coming from the three reference rooms considered is 0.90(45) mSv/yr, and maximum internal hazard index is 0.77(24), both for the compact clay brick reference room. The principal gamma radiation sources are cement, sand and bricks. © 2010 American Institute of Physics.
- Effective gamma-ray doses due to natural radiation from soils of southeastern Brazil(2010-12-05) Marcilei Aparecida Guazzelli; MEDINA, N. H.; MOREIRA, R. H.; BELLINI, B. S.; AGUIAR, V. A. P.We have used gamma-ray spectrometry to study the distribution of natural radiation from soils of southeastern Brazil: Billings reservoir, São Bernardo do Campo Parks, Diadema Parks, Interlagos region, São Paulo, and soil from São Paulo and Rio de Janeiro beaches. In most of the regions studied we have found that the dose due the external exposure to gamma-rays, proceeding from natural terrestrial elements, are between the values 0.3 and 0.6 mSv/year, established by the United Nations Scientific Committee on the Effects of Atomic Radiation. © 2010 American Institute of Physics.
- Sequential chemical extraction for a phosphogypsum environmental impact evaluation(2013-01-05) GENNARI, R. F.; GARCIA, I.; MEDINA, N. H.; Marcilei Aparecida GuazzelliPhosphogypsum (PG) is gypsum generated during phosphoric acid production. PG is stocked in large stacks or accumulated in lakes; it contains heavy metals and naturally occurring radioactive elements. The metal contamination may affect the functionality, sustainability and biodiversity of ecosystems. In this work, PG samples were analyzed by Plasma Spectrometry. Total metal content and in the extractable fraction of chemical elements were determined. For K, Ni, Zn, Cr, Cd, Ba, Pb and U, the results obtained are lower than those obtained in a Idaho plant are including and also lower than those found in the soil, indicating this PG sample analyzed probably will not cause any additional metal neither natural radiation contamination. © 2013 AIP Publishing LLC.
- Electronic system for data acquisition to study radiation effects on operating MOSFET transistors(2014-09-01) DE OLIVEIRA, J. A.; DE MELO, M. A. A.; Marcilei Aparecida Guazzelli; MEDINA, N. H.© 2014 AIP Publishing LLC.In this work we present the development of an acquisition system for characterizing transistors under X-ray radiation. The system is able to carry out the acquisition and to storage characteristic transistor curves. To test the acquisition system we have submitted polarized P channel MOS transistors under continuous 10-keV X-ray doses up to 1500 krad. The characterization system can operate in the saturation region or in the linear region in order to observe the behavior of the currents or voltages involved during the irradiation process. Initial tests consisted of placing the device under test (DUT) in front of the X-ray beam direction, while its drain current was constantly monitored through the prototype generated in this work, the data are stored continuously and system behavior was monitored during the test. In order to observe the behavior of the DUT during the radiation tests, we used an acquisition system that consists of an ultra-low consumption16-bit Texas Instruments MSP430 microprocessor. Preliminary results indicate linear behavior of the voltage as a function of the exposure time and fast recovery. These features may be favorable to use this device as a radiation dosimeter to monitor low rate X-ray.
- Traces of natural radionuclides in animal food(2014) MERLI, I. D.; Marcilei Aparecida Guazzelli; MEDINA, N. H.© 2014 AIP Publishing LLC.Naturally occurring radioactive materials are present everywhere, e.g., in soil, air, housing materials, food, etc. Therefore, human beings and animals receive internal exposure from radioactive elements inside their bodies through breathing and alimentation. Gamma radiation has enough energy to remove an electron from the atom and compromise the rearrangement of electrons in the search for a more stable configuration which can disturb molecule chemical bonding. Food ingestion is one of the most common forms of radioisotopes absorption. The goal of this work is the measurement of natural gamma radiation rates from natural radioisotopes present in animal food. To determine the concentration of natural radionuclides present in animal food gamma-ray spectrometry was applied. We have prepared animal food samples for poultry, fish, dogs, cats and cattle. The two highest total ingestion effective doses observed refers to a sample of mineral salt cattle, 95.3(15) μSv/year, rabbit chow, with a value of 48(5) μSv/year, and cattle mineral salt, with a value of 69(7) μSv/year, while the annual total dose value from terrestrial intake radionuclide is of the order of 290 μSv/year.
- Electric field and temperature effects in irradiated MOSFETs(2016-12-04) Marcilei Aparecida Guazzelli; SANTOS, R. B. B.; LEITE, F. G.; ARAUJO, N. E.; CIRNE, K. H.; MELO, M. A. A.; RALLO, A.; AGUIAR, V. A. P.; AGUIRRE, F.; MACCHIONE, E. L. A.; ADDED, N.; MEDINA, N.H.© 2016 Author(s).Electronic devices exposed to ionizing radiation exhibit degradation on their electrical characteristics, which may compromise the functionality of the device. Understanding the physical phenomena responsible for radiation damage, which may be specific to a particular technology, it is of extreme importance to develop methods for testing and recovering the devices. The aim of this work is to check the influence of thermal annealing processes and electric field applied during irradiation of Metal Oxide Semiconductor Field Effect Transistors (MOSFET) in total ionizing dose experiments analyzing the changes in the electrical parameters in these devices.
- High natural radiation in Brazilian sands(2012) Silveira M.A.G.; Medina N.H.; Pereira B.R.; Aguiar V.A.P.The present work investigated Brazilian beach sands in order to analyze the total external natural radiation dose using a gamma-ray spectrometry technique. The activities from the radionuclides 40K and the elements from the series of 238U and 232Th were measured. The sand samples from Morro Branco beach, Ceará, and Itacaré beach, Bahia, presented different colors and grain size than the beaches from São Paulo. A sample collected in Itacaré beach showed an effective dose of 2.5 (1) mSv/yr. This value is outside the annual typical range (0.3-0.6 mSv) indicated by the United Nations Scientific Committee on the Effects of Atomic Radiation. The high effective dose found in Itacaré beach is mainly due to the presence of a large amount of 232Th and 238U. All the other samples collected in Ceará and São Paulo States are inside the annual typical range. Energy-Dispersive X-Ray Spectroscopy (EDS) microanalysis showed that this high external radiation is related to the presence of zircon and monazite, which commonly carry traces of uranium and thorium. © 2012 American Institute of Physics.