Departamento de Física
URI permanente desta comunidadehttps://repositorio.fei.edu.br/handle/FEI/785
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10 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.
- In-beam gamma-ray spectroscopy in the sdpf 37Ar nucleus(2007-05-11) Marcilei Aparecida Guazzelli; MEDINA, N. H.; SEALE, W. A.; RIBAS, R. V.; DE OLIVEIRA, J. R. B.; ZILIO, S.; LENZI, S. M.; NAPOLI, D. R.; MARGINEAN, N.; VEDOVA, F. D.; FARNEA, E.; IONESCU-BUJOR, M.; IORDACHESCU, A.The nucleus 37Ar has been studied with γ-ray spectroscopy in the 24Mg(16O,2pn) reaction at a beam energy of 70 MeV. Twenty two new excited states up to an excitation energy of 13 MeV have been observed. We compare the first negative and positive parity yrast states with large-scale-shell-model calculations using the Antoine code and the SDPF interaction, considering the excitation of the 1d5/2,2s1/2 and 1d3/2 nucleons to 1f7/2 and 2p3/2 in the sdpf valence space. © 2007 American Institute of Physics.
- Natural radiation from soil using gamma-ray spectrometry(2009-05-12) Marcilei Aparecida Guazzelli; MOREIRA, R. H.; DE PAULA, A. L. C.; MEDINA, N. H.We have studied the distribution of natural radioactivity in the soil of Interlagos, in São Paulo city and Billings Reservoir, in São Bernardo do Campo, São Paulo, Brazil. The main contribution of the effective radiation dose is due to the elements of the 238Th decay series, with smaller contributions from 40K and the elements of the series of 238U. The results indicate the dose in all of the studied areas is around the average international dose due to external exposure to gamma rays (0.48 mSv/yr) proceeding from natural terrestrial elements. © 2009 American Institute of Physics.
- 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.
Artigo Effective gamma-ray doses due to natural radiation from soil of southeastern Brazil(2010) SILVEIRA, M. A. G.; Guazzelli, Marcilei A.; MEDINA, N. H.; MOREIRA, R. H.; AGUIAR, V. A. P.; BELLINI, B. S.