RENATO SEMMLER

RENATO SEMMLER

(Fonte: Lattes)

Resumo

Graduado em Física pela Pontifícia Universidade Católica de São Paulo (1989), Mestre em Tecnologia Nuclear pela Universidade de São Paulo (1993) e Doutor em Tecnologia Nuclear pela Universidade de São Paulo (2006). Atualmente é pesquisador da Comissão Nacional de Energia Nuclear (CNEN), lotado no Centro do Reator de Pesquisas (CERPq) do Instituto de Pesquisas Energéticas e Nucleares (IPEN). Docente da pós-graduação stricto sensu - Programa de tecnologia nuclear do IPEN - Universidade de São Paulo e da pós-graduação stricto sensu - Mestrado profissional de tecnologia das radiações na saúde. Tem experiência na área de Física Nuclear de baixas energias atuando nos seguintes temas: reações de captura de nêutrons térmicos (prompt gamma rays), método k0 de análise por ativação neutrônica, caracterização do espectro de nêutrons junto aos canais de irradiação do reator IEA-R1, espectroscopia gama, fotodesintegração, reações fotonucleares (fotofissão e fotonêutrons) e ensino de física. Professor e organizador da EAEN - Escola Avançada de Energia Nuclear para estudantes do Ensino Médio, preferencialmente envolvidos com olimpíadas de física e química: Teoria e Aplicações das Ciências Nucleares. Professor de física com mais de 25 anos de experiência em cursos universitários, pré-vestibular e ensino médio. (Texto extraído do Currículo Lattes em 27 dez. 2021)

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Preliminary measurements using a Triple to Double Coincidence Ratio (TDCR) Liquid Scintillator Counter System
2021 - KOSKINAS, M.F.; KUZNETSOVA, M.; MOREIRA, D.S.; SHOUERI, R.M.; YAMAZAKI, I.M.; MORAIS, T.S.L.; SEMMLER, R.; DIAS, M.S.
The preliminary measurements using a Triple to Double Coincidence Ratio (TDCR) Liquid Scintillator Counter System, developed by the Nuclear Metrology Laboratory (LMN) at IPEN, is presented and 14C was selected to be standardized. This solution was previously calibrated by the efficiency tracing technique using a (PC)coincidence system, employing 60Co as a tracer. In order to determine the final activity, a Monte Carlo simulation was used to generate the extrapolation curve. The Software Coincidence System (SCS) developed by the LMN was used for both systems to register the events. MICELLE 2 code was used to calculate the theoretical TDCR efficiency. Measurements using HIDEX, a commercial liquid scintillator system, were also carried out and the results from the three methods were compared, showing a good agreement.
Primary standardization and determination of gamma ray emission intensities of Ho-166
2020 - YAMAZAKI, I.M.; KOSKINAS, M.F.; MOREIRA, D.S.; SEMMLER, R.; BRANCACCIO, F.; DIAS, M.S.
The procedure followed by the Nuclear Metrology Laboratory (LMN) at the IPEN-CNEN/SP, in S~ao Paulo, for the primary standardization of 166Ho is described. The activity of 166Ho was determined by the efficiency extrapolation technique applied to a 4πβ(PC)-γ coincidence system using a gas flow proportional counter in 4π geometry coupled to a 76 x 76 mm NaI(Tl) crystal. The results for the γ-rays intensities at 80.57 and 1379.45 keV were 0.0651(11) and 0.00904(11), respectively.
Consistency test of coincidence-summing calculation methods for extended sources
2020 - SIMA, O.; DE VISMES OTT, A.; DIAS, M.S.; DRYAK, P.; FERREUX, L.; GURAU, D.; HURTADO, S.; JODLOWSKI, P.; KARFOPOULOS, K.; KOSKINAS, M.F.; LAUBENSTEIN, M.; LEE, Y.K.; LEPY, M.C.; LUCA, A.; MENEZES, M.O.; MOREIRA, D.S.; NIKOLIC, J.; PEYRES, V.; SAGANOWSKI, P.; SAVVA, M.I.; SEMMLER, R.; SOLC, J.; THANH, T.T.; TYMINSKA, K.; TYMINSKI, Z.; VIDMAR, T.; VUKANAC, I.; YUCEL, H.
An internal consistency test of the calculation of coincidence-summing correction factors FC for volume sources is presented. The test is based on exact equations relating the values of FC calculated for three ideal measurement configurations. The test is applied to a number of 33 sets of FC values sent by 21 teams. Most sets passed the test, but not the results obtained using the quasi-point source approximation; in the latter case the test qualitatively indicated the magnitude of the bias of FC.
SUMCOR
2018 - DIAS, M.S.; SEMMLER, R.; MOREIRA, D.S.; MENEZES, M.O. de; BARROS, L.F.; RIBEIRO, R.V.; KOSKINAS, M.F.
The main features of code SUMCOR developed for cascade summing correction for volumetric sources are described. MCNP6 is used to track histories starting from individual points inside the volumetric source, for each set of cascade transitions from the radionuclide. Total and FEP efficiencies are calculated for all gamma-rays and X-rays involved in the cascade. Cascade summing correction is based on the matrix formalism developed by Semkow et al. (1990). Results are presented applying the experimental data sent to the participants of two intercomparisons organized by the ICRM-GSWG and coordinated by Dr. Marie-Cristine Lepy from the Laboratoire National Henri Becquerel (LNE-LNHB), CEA, in 2008 and 2010, respectively and compared to the other participants in the intercomparisons.
Gamma-ray impurities of 111In, 201Tl, 177Lu and 99mTc determined by means of a HPGE spectrometer
2017 - KOSKINAS, MARINA F.; ALMEIDA, JAMILLE da S.; MOREIRA, DENISE S.; SEMMLER, RENATO; DIAS, MAURO da S.
This work aims to present the radioactive impurities gamma rays emitters detected in some radiopharmaceuticals widely applied to diagnosis and therapy purposes, supplied to nuclear medicine services in Brazil by the Radiopharmaceutical Center(CR) of Nuclear and Energy Research Institute, IPEN, in São Paulo. The analysis was undertaken by means of an HPGe gamma spectrometer. The radiopharceuticals analyzed were: 111In, 201Tl, 177Lu and 99mTc.
Caracterizacao e calibracao do feixe de radiacao gama de captura no reator IEA-R1
1995 - GERALDO, L.P.; PADILHA, M.C.; SEMMLER, R.; TERREMOTO, L.A.A.; DIAS, M.S.
Montagem e calibracao de um novo arranjo experimental para a producao e utilizacao de radiacao gama de captura
1992 - SEMMLER, R.; GERALDO, L.P.
Effects of gamma radiation on the pBs-KS DNA plasmid
2001 - ARRUDA NETO, J.D.T.; SHTEJER, K.; ZAMBONI, C.B.; DUARTE, C.L.; SEMMLER, R.; JORGE, S.A.C.; GOUVEIA, A.N.; DEPPMAN, A.; ARAUJO, G.W.
Effects of gamma radiation on the pBs-KS DNA plasmid
2001 - ARRUDA NETO, J.D.T.; ZAMBONI, C.B.; DUARTE, C.L.; SEMMLER, R.; JORGE, S.A.C.; ARAUJO, G.W.; SHTEJER, K.; GOUVEIA, A.N.; DEPPMAN, A.; HELENE, O.A.M.; VANIN, V.R.; LIKHACHEV, V.P.; MANSO GUEVARA, M.V.; MIRANDA, A.; RODRIGUEZ, O.
DNA is considered to be the most important and critical target in a cell from the point of view of radiation damage. It is responsible for conservation and transmission of all the cell genetic information. It is constantly submitted to different kind of damages, where repair could or couldn't take place. The energy transferred by ionizing radiation to the DNA strands can induce mutation, carcinogenic process and cell death. The DNA damage involves nucleotide base alterations, single (SSB) and double (DSB) strand breaks and also chromatin rupture. The DNA strand break (mainly DSB) is the most critical damage induced by ionizing radiation. Specifically. gamma radiation is used in a large number of illness treatment including cancer diagnosis, treatment and cure. In fact, this radiation is the base of conventional radiotherapy using ®9Co and ?%7Cs sources. Beside, this radiation is also present in treatment which involves neutrons and others types of particles, such as protons, alphas and heavy ions ( e.g. Ne. Ar). The 250 MeV proton beam therapy, largely used in recent years as an effective non invasive cancer treatment. produces gamma rays as a secondary radiation which can generate radiobiological effects on healthy tissue. This kind of radiation with low linear energy transfer (LET) interacts with the tissue producing secondary electrons. which directly produce excited and ionized states into the DNA strands and inducing the formation of energetic free radicals in the aqueous solution containing the DNA molecule. The DNA strand damages produced by these interactions must be well known in order to prevent the radiobiological effects on human being The investigation of DNA radiation effects has been very intensive in the last years!'=3), and the present study is a contribution to better understand the mechanism of single (SSB) and double (DSB) strand breaks of pBs KS (+) plasmid DNA with 1 MeV gamma radiation. About 10 ml of DNA was irradiated at a concentration of 15 ng/ml in a cylindrical plastic tube (eppendorf) in the ®®Co Gamma Cell at IPEN ( Instituto de Pesquisas Energeticas e Nucleares, Sao Paulo) facility. The dose rate was 5 kGy/h, and the biological material was submitted to total doses ranging from 0 to 200 Gy. Supercoiled (FI),Circular (FII) and Linear (FIII) forms of the plasmid were separated by agarose gel electrophoresis at 10 volts overnight with 1% agarose. The results exhibit a decreasing of the FI plasmid fraction and an increasing number of the FII and FIII fractions with the dose, suggesting the presence of SSBs and DSBs in the irradiated DNA plasmid. The detectable molecule fractions of each form of plasmid were analyzed by means of a statistical treatment[%) allowing the calculation of the average number of SSB and DSB per plasmid for each interaction dose.These two quantities are shown in the figure. The curve is only to guide the eyes(preliminary data). In this analysis it was assumed that the strand break distribution obeys Poisson' laws. These calculations were compared with the corresponding experimental data. It was found that the statistical results describe satisfactory the data for gamma radiation.
Photoneutron cross sections measurements in sup(9)Be with thermal neutron capture gamma-ray
2006 - SEMMLER, R.; CARBONARI, A.W.; GONCALEZ, O.L.