CLAUDIO DOMIENIKAN
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Resumo IPEN-doc 26847 A compact electronic system for a photodiode neutron detector2019 - COSTA, PRISCILA; RAELE, MARCUS P.; DOMIENIKAN, CLAUDIO; COSTA, FABIO E.; MADI FILHO, TUFIC; ZAHN, GUILHERME S.; GENEZINI, FREDERICO A.The demand for portable neutron detectors is on the rise, and for that purpose, low cost boron-10 has been frequently used instead of helium-3, which is usually employed in large and expensive detectors. Portable detectors are of interest in some applications, such as neutron dosimeters or inspection systems targeted in the detection of fissile material and drugs in airports. In this work a portable thermal neutron detection system was developed which is based on a commercial silicon photodiode coupled to a boron converter; this prototype is then plugged into a portable electronic system. The boron layer was produced by pulsed laser deposition, either on a thin glass slide or on the photodiode itself. The boron deposition in the photodiode was made directly in the active area of the detector, so before and after the deposition process a characterization of the device regarding both the dark current and the operation voltage was performed using an americium source. Finally, both configurations were tested. The neutron detection process occurs by detecting the alpha and lithium particles produced by the interaction of the incoming neutron with the boron-10 nuclides. These heavy ions then interact with the active area of the reverse-biased photodiode, producing an electric signal that has to be preamplified and then properly amplified by the portable electronic system, which in turn produces an output that can either be sent to a multichannel analyzer or to a digital counter. The integrated circuit of the low noise preamplifier transforms the detector’s current pulse into a voltage pulse with amplitude proportional to the charge carried by the current pulse. The shaper-driver consists of a differentiator and an integrator and is responsible for filtering and further amplifying the preamplifier signal, generating a NIM-compatible energy output pulse. The performance of the photodiode-amplifier set for alpha particles was successively tested using a 243Am radioactive source. Initial tests were made using the boron-deposited glass, and the electronic signal was properly read. However, when the same system was tested using the boron deposited directly in the photodiode, the output signal couldn’t be read, due to the fact that during the deposition process there was an increase in the dark current and a decrease in the operation bias. In this way, a new portable electronic system was developed using a hybrid integrated amplifier circuit. This new electronic setup allowed the use of both configurations, and was tested both with alpha-emitting Americium and neutron-emitting AmBe sources. In conclusion, both portable electronic systems have proven suitable for the thermal neutron detector developed.Resumo IPEN-doc 23305 Hyperfine field at La in the intermetallic compound LaMnSi2 measured by PAC using 140Ce nuclear probe2016 - DOMIENIKAN, CLAUDIO; BOSCH-SANTOS, BRIANNA; PASCA, GABRIEL A.C.; SAXENA, RAJENDRA; CARBONARI, ARTURMagnetic hyperfine field has been measured in the orthorhombic intermetallic compound LaMnSi2 with PAC spectroscopy using radioactive 140La-140Ce nuclear probes. Magnetization measurement was also carried out in this compound with MPSM-SQUID magnetometer. The LaMnSi2 sample was prepared by melting pure metallic components in stoichiometric proportions in an arc furnace under argon atmosphere. After melting, the sample was annealed at 1000 o C for 60h under helium atmosphere and then quenched in to water. X-ray analysis confirmed the sample to be in a single phase with correct crystal structure expected for LaMnSi2. The radioactive nuclei, 140La (T1/2 = 40h) were produced by direct irradiation of the sample with neutrons in the IEA-R1 nuclear research reactor at IPEN with a flux of ~1013 ncm-2s-1 for about 3-4 min. The irradiated sample was annealed at 1000 o C under helium atmosphere for 24 hours before starting the PAC measurement in order to minimize the effects of eventual radiation damage by fast neutrons during irradiation as well as to allow the decay of the short lived 56Mn (T1/2 = 2.6h) activity also produced in the sample. The PAC measurements were carried out with a six BaF2 detector spectrometer at several temperatures between 10 K and 400 K. The results showed well defined magnetic dipole interaction at all temperatures. Temperature dependence of the hyperfine field, Bhf was found to be anomalous. The magnetization measurement however, showed no anomaly. Therefore, the anomalous behavior of Bhf may be attributed to the interaction where 1f electron of the dilute Ce atom is spin polarized by the magnetic field from Mn sublattice and contributes to the effective hyperfine field. The ferromagnetic transition temperature (TC) of LaMnSi2 was determined to be 400(1) K confirming by magnetic measurement and the earlier results.Resumo IPEN-doc 22330 Hyperfine field at Mn in the intermetallic compound LaMnSi2 measured by PAC using sup(111)Cd nuclear probe2014 - DOMIENIKAN, CLAUDIO; SANTOS, BRIANNA B.; CABRERA PASCA, GABRIEL A.; SAXENA, RAJENDRA N.; CARBONARI, ARTUR W.Resumo IPEN-doc 09234 Routing interface for multidetector angular correlation spectrometer2003 - DOMIENIKAN, C.; GENEZINI, F.A.; ZAHN, G.S.; MEDEIROS, J.A.G.; CRUZ, M.T.F.Resumo IPEN-doc 18775 A six-BaFsub(2) detectors PAC spectrometer for measurements with short lived nuclear probes2012 - DOMIENIKAN, CLAUDIO; LAPOLLI, ANDRE L.; SANTOS, BRIANNA B. dos; CARBONARI, ARTUR W.; SAXENA, RAJENDRA N.; SCHOUERI, ROBERTO M.