PAULO DE TARSO DALLEDONE SIQUEIRA

PAULO DE TARSO DALLEDONE SIQUEIRA

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BNCT research facility at IEA-R1m reactor
2006 - COELHO, P.R.P.; SILVA, G.S.A.; SIQUEIRA, P.T.D.; YORIYAZ, H.; MUNIZ, R.O.R.; NASCIMENTO, J.F.; CARNEIRO, V.J.
A BNCT (Boron Neutron Capture Therapy) research facility was constructed at IPEN-IEA-R1m reactor. From its conception up to its final configuration around a decade went by. Its final design changed along the way, either to attend more stringent safety criteria or as a consequence of money shortage and management. The facility installed at beam-hole (BH) number 3 can be described to be consisted of 2 modules: - an inner BH module: with the filter, sample and shielding arrangement sets and - an out of wall module: with biological shielding room surrounding the sample positioning/removing table. Neutron/gamma spectra can be modulated by a set of filters interposed between the reactor core and the sample position. As the sample irradiation region is inside BH, sample size is limited to a cylindrical enclosure of 30.0 cm height by 12.8 cm in diameter. Due to its size limit, the facility is not suited to carry any treatment. However neutron fluxes attained at the sample irradiation position is high enough to reproduce adequate conditions to perform experiments in Neutron Capture Therapy. The biological shielding at the end of the BH was designed and constructed to allow the extraction of the sample (and the inner shielding with it) even with the reactor on. This feature together with a remote controlling sample positioning/removing system enables controlling the sample exposition time (dose). All these features together have provided irradiation conditions well fitted to perform experiments in research fields other than BNCT. Experiment such as: - neutron radiation biological damage; - neutron dosimetry and - neutron detectors have been carried out in this facility. This work intends to present this facility to the Nuclear community, showing its characteristics, limits and potentialities in order to establish new working partnerships, which can profit from a forthcoming extended reactor operating program.
Nuclear reactions, applications and computation
2003 - DEPPMAN, A.; ARRUDA NETO, J.D.T.; LIKHACHEV, V.P.; MARTINS, M.N.; PEREIRA, S.A.; MESA HORMAZA, J.; SANTOS, A.; COELHO, P.R.P.; YORIYAZ, H.; SIQUEIRA, P.T.; ANDRADE e SILVA, G.S.; TAVARES, O.A.P.; DUARTE, S.B.; MEDEIROS, E.L.; GONCALVES, M.; PAIVA, E.; GARCIA, F.; DIMARCO, A.
Radiation field characterization of the NCT research facility at IEA-R1
2008 - COELHO, P.R.P.; MUNIZ, R.O.R.; NASCIMENTO, J.F.; SILVA, G.S.A.; SIQUEIRA, P.T.D.; YORIYAZ, H.; CARNEIRO, V.J.
Projeto da blindagem biologica de uma instalacao para estudos em BNCT no reator IEA-R1
2002 - ANDRADE e SILVA, G.S.; COELHO, P.R.P.; SIQUEIRA, P.T.D.
Neutron flux calculation in a BNCT research facility implemented in IEA-R1 reactor
2002 - COELHO, P.R.P.; HERNANDES, A.C.; SIQUEIRA, P.T.D.
Shielding design for a research facility in the IEA-R1 Reactor
2002 - ANDRADE e SILVA, G.S.; COELHO, P.R.P.; SIQUEIRA, P.T.D.
A 'non-coincident' Neutron Coincidence Collar response simulation
2002 - SIQUEIRA, P.T.D.; COELHO, P.R.P.; YORIYAZ, H.; CABEZAS SOLORZANO, R.
Improvements in the biological shielding of the BNCT facility at the IEA-R1 reactor
2011 - SOUZA, GREGORIO S. de; COELHO, PAULO R.P.; SIQUEIRA, PAULO de T.D.
MCNP study the BFsub(3) detection efficiency
2011 - CASTRO, VINICIUS A.; CAVALIERI, TASSIO A.; SIQUEIRA, PAULO T.D.; FEDORENKO, GIULIANA G.; COELHO, PAULO R.P.; MADI FILHO, TUFIC
Neutron flux and gama dose profile measurements and calculations along a phantom in the BNCT facility of IEA-R1 reactor
2010 - MUNIZ, R.O.R.; COELHO, P.R.P.; SILVA, G.S.A.; SIQUEIRA, P.T.D.; SOUSA, G.S.
A BNCT (Boron Neutron Capture Therapy) facility has been built at IEA-R1 reactor. The on going BNCT experiments demand the maximization of the thermal neutron component of the irradiation fi eld and the minimization of its epithermal and fast neutron components together with the reduction of the gamma contamination. This work was developed with the objective of evaluating whether the present radiation fi eld in the facility is suitable for carrying on BNCT studies and to establish a work methodology with phantoms in this facility. In order to achieve these objectives, thermal and epithermal neutron fl ux measurements, in the sample irradiation position were performed using hyper-pure Gold activation detectors and applying the Cadmium ratio. Absorbed dose due to gamma radiation was determined by TLD 400. A cylindrical phantom composed by acrylic discs was designed, built and tested in the facility. DOT 3.5 computational code was used to retrieve neutron fl uxes and the gamma dose estimates along the phantom. Although some improvements still need to be made in the methodology under implementation, computer simulations carried out with DOT code presented a good agreement with experimental data for most part of the evaluated profi le. In the position corresponding to about half the length of the phantom, the following experimental values were obtained: thermal neutron fl ux (2.52 ± 0.06)·108 n.cm-2.s-1, epithermal neutron fl ux (6.2 ± 0.3)·106 n.cm-2.s-1, absorbed dose due to thermal neutrons (4.2 ± 1.8) Gy and (10.1 ± 1.3) Gy due to gamma radiation. The obtained values show that the fl uxes of thermal and epithermal neutrons fl ux are appropriate for studies in BNCT, however, dose due to gamma radiation is high, indicating that the facility should be improved.