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2.
Phys Med ; 89: 226-231, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34425513

RESUMO

The aim of the NEPTUNE (Nuclear process-driven Enhancement of Proton Therapy UNravEled) project is to investigate in detail both the physical and radiobiological phenomena that could justify an increase of the proton-induced cytogenetic effects in cells irradiated in presence of an agent containing natural boron. In this work, a double-stage silicon telescope coupled to different boron converters was irradiated at the CATANA proton therapy facility (INFN-LNS) for studying the proton boron fusion and the neutron boron capture reactions by discriminating secondary particles from primary protons. Different boron targets were developed by depositing boric acid, enriched with a higher than 99% content of 10B or 11B, on a 50 µm thick PolyMethilMetacrylate (PMMA) substrate. The 10B target allows to evaluate the contribution of lithium and alpha particles produced by the boron neutron capture reaction triggered by secondary thermal neutrons, while the 11B target is exploited for studying the effect of the p + 11B → 3α nuclear reaction directly triggered by primary protons. Experimental results clearly show the presence of alpha particles from both the reactions. The silicon telescope is capable of discriminating, by means of the so-called "scatter plots", the contribution of alpha particles originated by thermal neutrons on 10B with respect to the ones produced by protons impinging on 11B. Although a reliable quantitative study of the alpha production rate has not been achieved yet, this work demonstrates that low energy and, therefore, high-LET particles from both the reactions can be measured.


Assuntos
Terapia por Captura de Nêutron de Boro , Terapia com Prótons , Boro , Nêutrons , Prótons
3.
Sci Adv ; 7(3)2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33523900

RESUMO

Among the existing elemental characterization techniques, particle-induced x-ray emission (PIXE) and energy-dispersive x-ray (EDX) spectroscopy are two of the most widely used in different scientific and technological fields. Here, we present the first quantitative laser-driven PIXE and laser-driven EDX experimental investigation performed at the Centro de Láseres Pulsados in Salamanca. Thanks to their potential for compactness and portability, laser-driven particle sources are very appealing for materials science applications, especially for materials analysis techniques. We demonstrate the possibility to exploit the x-ray signal produced by the co-irradiation with both electrons and protons to identify the elements in the sample. We show that, using the proton beam only, we can successfully obtain quantitative information about the sample structure through laser-driven PIXE analysis. These results pave the way toward the development of a compact and multifunctional apparatus for the elemental analysis of materials based on a laser-driven particle source.

4.
Hum Exp Toxicol ; 39(3): 262-275, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31640425

RESUMO

Chalcones are naturally occurring compounds exhibiting biological activity through multiple mechanisms. Flavokawain B is one of chalcones found in kava plant. In our studies, we focused on the anticancer activity of flavokawain B in colorectal cancer cells LoVo and its resistant to doxorubicin subline-LoVo/Dx. Strong cytotoxic activity of flavokawain B and its ability to inhibit the proliferation in both cell lines was detected. These effects accompanied with induction cell cycle arrest in G2/M phase and the presence of SubG1 fraction. Flavokawain B at low concentration led to increase of caspase-3 activity. The chalcone-induced apoptosis was also confirmed by DNA fragmentation. In our work, the conversion of flavokawain B to corresponding flavanone-5,7-dimetoxyflavanone-was shown to be more extensive in cancer than in non-cancer cells. We found that the cyclization of the chalcone was related to the significant decrease in the cytotoxicity. Cell proliferation and cell cycle progression were not impaired significantly in the studied cancer cells incubated with 5,7-dimethoxyflavanone. We did not observe apoptosis in the cells incubated with flavanone. The results from biological studies agreed with the theoretical activity that emerges from structural parameters.


Assuntos
Adenocarcinoma , Sobrevivência Celular/efeitos dos fármacos , Neoplasias Colorretais , Flavonoides/química , Flavonoides/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Apoptose , Caspase 3/metabolismo , Linhagem Celular Tumoral , Ciclização , Humanos , Relação Estrutura-Atividade
5.
Radiat Prot Dosimetry ; 183(1-2): 177-181, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30535177

RESUMO

The tissue-equivalent proportional counter (TEPC) is the most accurate device for measuring the microdosimetric properties of a particle beam but, since the lower operation limit of common TEPCs is ~0.3 µm, no detailed information on the track structure of the impinging particles can be obtained. The pattern of particle interactions at the nanometric level is measured directly by only three different nanodosimeters worldwide: practical instruments are not yet available. In order to partially fill the gap between microdosimetry and track-nanodosimetry, a low-pressure avalanche-confinement TEPC was designed and constructed for simulating tissue-equivalent sites down to the nanometric region. The present paper aims at describing the response of this TEPC in the range 0.3 µm-25 nm to a 62 MeV/n 4He ion beam. The experimental results, for depths near the Bragg peak, show good agreement with FLUKA simulations and suggest that, for smaller depths, the distribution is highly influenced by secondary electrons.


Assuntos
Hélio/química , Nanotecnologia , Radiometria/instrumentação , Simulação por Computador , Desenho de Equipamento , Modelos Teóricos
6.
Appl Radiat Isot ; 142: 38-41, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30248587

RESUMO

CSYP (CYlindrical SPectrometer) is a directional neutron spectrometer based on a single moderator embedding multiple thermal neutron detectors. Similarly to Bonner Spheres, CYSP responds from thermal up to GeV neutrons and the spectrum is obtained via few-channel unfolding methods. CYSP has the shape of a polyethylene cylinder with diameter 50 cm and height 65 cm. Owing on a thick collimator and on a specifically designed shielding structure, the internal detectors only respond to neutrons coming from a known direction. Internal thermal neutron detectors are one-cm2 6LiF-covered silicon diodes. Un upgraded version of CYPS was developed to work in low intensity applications, such as cosmic field measurements. It is called CYSP-HS (High-Sensitivity) and is equipped with large area 6LiF-covered silicon diodes (LATND, Large Area Thermal Neutron Detectors). Compared with the former CYSP, the sensitivity increased approximately by an order of magnitude. This paper presents CYSP-HS focusing on the new internal detectors, the response matrix and its verification in a reference field of Am-Be available at the Politecnico di Milano.

7.
Phys Med ; 52: 113-121, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30139599

RESUMO

PURPOSE: The aim of this paper is to investigate the limits of LET monitoring of therapeutic carbon ion beams with miniaturized microdosimetric detectors. METHODS: Four different miniaturized microdosimeters have been used at the 62 MeV/u 12C beam of INFN Southern National Laboratory (LNS) of Catania for this purpose, i.e. a mini-TEPC and a GEM-microdosimeter, both filled with propane gas, and a silicon and a diamond microdosimeter. The y-D (dose-mean lineal energy) values, measured at different depths in a PMMA phantom, have been compared withLET¯D (dose-mean LET) values in water, calculated at the same water-equivalent depth with a Monte Carlo simulation setup based on the GEANT4 toolkit. RESULTS: In these first measurements, no detector was found to be significantly better than the others as a LET monitor. The y-D relative standard deviation has been assessed to be 13% for all the detectors. On average, the ratio between y-D and LET¯D values is 0.9 ±â€¯0.3, spanning from 0.73 ±â€¯0.08 (in the proximal edge and Bragg peak region) to 1.1 ±â€¯0.3 at the distal edge. CONCLUSIONS: All the four microdosimeters are able to monitor the dose-mean LET with the 11% precision up to the distal edge. In the distal edge region, the ratio of y-D to LET¯D changes. Such variability is possibly due to a dependence of the detector response on depth, since the particle mean-path length inside the detectors can vary, especially in the distal edge region.


Assuntos
Radiometria/instrumentação , Calibragem , Isótopos de Carbono/uso terapêutico , Simulação por Computador , Desenho de Equipamento , Radioterapia com Íons Pesados/instrumentação , Miniaturização , Método de Monte Carlo , Imagens de Fantasmas , Polimetil Metacrilato , Dosagem Radioterapêutica , Água
8.
Radiat Prot Dosimetry ; 180(1-4): 304-308, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29361156

RESUMO

Radiation-resistant, gamma-insensitive, active thermal neutron detectors were developed to monitor the thermal neutron cavity of the E_LIBANS project. Silicon and silicon carbide semiconductors, plus vented air ion chambers, were chosen for this purpose. This communication describes the performance of these detectors, owing on the results of dedicated measurement campaigns.


Assuntos
Compostos Inorgânicos de Carbono/química , Nêutrons , Monitoramento de Radiação/instrumentação , Monitoramento de Radiação/métodos , Proteção Radiológica/instrumentação , Semicondutores/normas , Compostos de Silício/química , Silício/química , Simulação por Computador , Desenho de Equipamento , Doses de Radiação , Temperatura
9.
Radiat Prot Dosimetry ; 180(1-4): 273-277, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29309701

RESUMO

The e_LiBANS project aims at producing intense thermal neutron fields for diverse interdisciplinary irradiation purposes. It makes use of a reconditioned medical electron LINAC, recently installed at the Physics Department and INFN in Torino, coupled to a dedicated photo-converter, developed within this collaboration, that uses (γ,n) reaction within high Z targets. Produced neutrons are then moderated to thermal energies and concentrated in an irradiation volume. To measure and to characterize in real time the intense field inside the cavity new thermal neutron detectors were designed with high radiation resistance, low noise and very high neutron-to-photon discrimination capability. This article offers an overview of the e_LiBANS project and describes the results of the benchmark experiment.


Assuntos
Nêutrons , Aceleradores de Partículas , Fótons , Doses de Radiação , Radiometria/instrumentação , Elétrons , Desenho de Equipamento , Raios gama , Pesquisa Interdisciplinar , Modelos Lineares
10.
Radiat Prot Dosimetry ; 180(1-4): 157-161, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29087524

RESUMO

The Italian National Centre for Oncological Hadrontherapy (CNAO) has been treating patients since 2011 with carbon-ion beams using the active-scanning modality. In such irradiation modality, the beam spot, which scans the treatment area, is characterised by very high particle-fluence rates (more than 105 s-1 mm-2). Moreover, the Bragg-peak is only ~1 mm-FWHM. Commercial tissue-equivalent proportional counters (TEPC), like the Far West Technologies LET-½, are large, hence they have limited capability to measure at high counting fluence rates. In this study we have used two home-made detectors, a mini-TEPC 0.81 mm2 in sensitive area and a silicon telescope 0.125 mm2 in sensitive area, to perform microdosimetric measurements in the therapeutic carbon-ion beam of CNAO. A monoenergetic carbon-ion beam of 189.5 ± 0.3 MeV/u scanning a 3 × 3 cm2 area has been used. Spectral differences are visible in the low y-value region, but the mean microdosimetric values, measured with the two detectors, result to be pretty consistent, as well as the microdosimetric spectra in the high y-value region.


Assuntos
Carbono/uso terapêutico , Instalações de Saúde , Microtecnologia/métodos , Aceleradores de Partículas/instrumentação , Monitoramento de Radiação/instrumentação , Radioterapia/instrumentação , Humanos , Transferência Linear de Energia
11.
Radiat Prot Dosimetry ; 180(1-4): 172-176, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29036508

RESUMO

Tissue equivalent proportional counter (TEPC) is the most accurate device for measuring the microdosimetric properties of a particle beam, nevertheless no detailed information on the track structure of the impinging particles can be obtained, since the lower operation limit of common TEPCs is ~0.3 µm. On the other hand, the pattern of particle interactions at the nanometer level is measured by only three different nanodosimeters worldwide: practical instruments are not yet available. In order to partially fill the gap between microdosimetry and track-nanodosimetry, a low-pressure avalanche-confinement TEPC was recently designed and constructed for simulating tissue-equivalent sites down to the nanometric region. The present article aims at describing the response of this newly developed TEPC in the range 0.3 µm-25 nm against a fast neutron field from a 241Am-Be source and a quasi-monoenergetic neutron beam. The experimental results are in good agreement with Monte Carlo simulations carried out with the FLUKA code.


Assuntos
Microtecnologia/instrumentação , Nanotecnologia/instrumentação , Nêutrons , Monitoramento de Radiação/instrumentação , Proteção Radiológica/instrumentação , Amerício/análise , Desenho de Equipamento , Doses de Radiação
12.
Appl Radiat Isot ; 123: 32-35, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28214683

RESUMO

One of the major causes of secondary malignancies after radiotherapy treatments are peripheral doses, known to increase for some newer techniques (such as IMRT or VMAT). For accelerators operating above 10MV, neutrons can represent important contribution to peripheral doses. This neutron contamination can be measured using different passive or active techniques, available in the literature. As far as active (or direct-reading) procedures are concerned, a major issue is represented by their parasitic photon sensitivity, which can significantly affect the measurement when the point of test is located near to the field-edge. This work proposes a simple method to estimate the unwanted photon contribution to these neutrons. As a relevant case study, the use of a recently neutron sensor for "in-phantom" measurements in high-energy machines was considered. The method, called "Dual Energy Photon Subtraction" (DEPS), requires pairs of measurements performed for the same treatment, in low-energy (6MV) and high energy (e.g. 15MV) fields. It assumes that the peripheral photon dose (PPD) at a fixed point in a phantom, normalized to the unit photon dose at the isocenter, does not depend on the treatment energy. Measurements with ionization chamber and Monte Carlo simulations were used to evaluate the validity of this hypothesis. DEPS method was compared to already published correction methods, such as the use of neutron absorber materials. In addition to its simplicity, an advantage of DEPs procedure is that it can be applied to any radiotherapy machine.


Assuntos
Nêutrons Rápidos , Fótons , Radiometria/métodos , Dosagem Radioterapêutica , Simulação por Computador , Nêutrons Rápidos/efeitos adversos , Humanos , Método de Monte Carlo , Neoplasias Induzidas por Radiação/etiologia , Segunda Neoplasia Primária/etiologia , Imagens de Fantasmas , Fótons/efeitos adversos , Radiometria/instrumentação , Radiometria/estatística & dados numéricos , Radioterapia de Intensidade Modulada/efeitos adversos , Espalhamento de Radiação
13.
Radiat Prot Dosimetry ; 173(1-3): 104-110, 2017 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-28100670

RESUMO

This communication describes two new instruments, based on multiple active thermal neutron detectors arranged within a single moderator, that permit to unfold the neutron spectrum (from thermal to hundreds of MeV) and to determine the corresponding integral quantities with only one exposure. This makes them especially advantageous for neutron field characterisation and workplace monitoring in neutron-producing facilities. One of the devices has spherical geometry and nearly isotropic response, the other one has cylindrical symmetry and it is only sensitive to neutrons incident along the cylinder axis. In both cases, active detectors have been specifically developed looking for the criteria of miniaturisation, high sensitivity, linear response and good photon rejection. The calculated response matrix has been validated by experimental irradiations in neutron reference fields with a global uncertainty of 3%. The measurements performed in realistic neutron fields permitted to determine the neutron spectra and the integral quantities, in particular H*(10).


Assuntos
Monitoramento de Radiação , Proteção Radiológica , Local de Trabalho , Desenho de Equipamento , Humanos , Nêutrons , Fótons , Doses de Radiação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
14.
Appl Radiat Isot ; 115: 49-54, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27337649

RESUMO

The increasing interest of the medical community to radioinduced second malignancies due to photoneutrons in patients undergoing high-energy radiotherapy, has stimulated in recent years the study of peripheral doses, including the development of some dedicated active detectors. Although these devices are designed to respond to neutrons only, their parasitic photon response is usually not identically zero and anisotropic. The impact of these facts on measurement accuracy can be important, especially in points close to the photon field-edge. A simple method to estimate the photon contribution to detector readings is to cover it with a thermal neutron absorber with reduced secondary photon emission, such as a borated rubber. This technique was applied to the TNRD (Thermal Neutron Rate Detector), recently validated for thermal neutron measurements in high-energy photon radiotherapy. The positive results, together with the accessibility of the method, encourage its application to other detectors and different clinical scenarios.


Assuntos
Nêutrons , Radiometria , Radioterapia de Alta Energia , Humanos , Fótons
15.
Appl Radiat Isot ; 107: 171-176, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26516990

RESUMO

A new thermal neutron irradiation facility based on an (241)Am-Be source embedded in a polyethylene moderator has been designed, and is called ETHERNES (Extended THERmal NEutron Source). The facility shows a large irradiation cavity (45 cm × 45 cm square section, 63 cm in height), which is separated from the source by means of a polyethylene sphere acting as shadowing object. Taking advantage of multiple scattering of neutrons with the walls of this cavity, the moderation process is especially effective and allows obtaining useful thermal fluence rates from 550 to 800 cm(-2) s(-1) with a source having nominal emission rate 5.7×10(6) s(-1). Irradiation planes parallel to the cavity bottom have been identified. The fluence rate across a given plane is as uniform as 3% (or better) in a disk with 30 cm (or higher) diameter. In practice, the value of thermal fluence rate simply depends on the height from the cavity bottom. The thermal neutron spectral fraction ranges from 77% up to 89%, depending on the irradiation plane. The angular distribution of thermal neutrons is roughly isotropic, with a slight prevalence of directions from bottom to top of the cavity. The mentioned characteristics are expected to be attractive for the scientific community involved in neutron metrology, neutron dosimetry and neutron detector testing.

16.
Radiat Prot Dosimetry ; 170(1-4): 326-30, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26276808

RESUMO

This communication describes a recently developed single-exposure neutron spectrometer, based on multiple active thermal neutron detectors located within a moderating sphere, which have been developed jointly by CIEMAT (Spain), INFN (Italy) and Politecnico di Milano (Italy) in the framework of Italian and Spanish collaboration projects. The fabricated prototypes permit to achieve spectrometric resolution with nearly isotropic response for neutron with energies from thermal to 100-200 MeV, thus being able to characterise the complete neutron spectrum in only one exposure by unfolding the measured responses of the detectors. This makes it especially advantageous for characterising neutron fields and workplace monitoring purposes in neutron-producing facilities.


Assuntos
Exposição Ocupacional/análise , Doses de Radiação , Dosímetros de Radiação , Monitoramento de Radiação/instrumentação , Proteção Radiológica/instrumentação , Análise Espectral/instrumentação , Calibragem , Humanos , Itália , Nêutrons , Exposição Ocupacional/prevenção & controle , Fótons , Polietileno , Monitoramento de Radiação/métodos , Proteção Radiológica/métodos , Reprodutibilidade dos Testes , Espanha , Local de Trabalho
17.
Appl Radiat Isot ; 106: 145-50, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26249744

RESUMO

The reliability of Fricke gel dosimeters in form of layers for measurements aimed at the characterization of epithermal neutron beams has been studied. By means of dosimeters of different isotopic composition (standard, containing (10)B or prepared with heavy water) placed against the collimator exit, the spatial distribution of gamma and fast neutron doses and of thermal neutron fluence are attained. In order to investigate the accuracy of the results obtained with in-air measurements, suitable MC simulations have been developed and experimental measurements have been performed utilizing Fricke gel dosimeters, thermoluminescence detectors and activation foils. The studies were related to the epithermal beam designed for BNCT irradiations at the research reactor LVR-15 (Rez). The results of calculation and measurements have revealed good consistency of gamma dose and fast neutron 2D distributions obtained with gel dosimeters in form of layers. In contrast, noticeable modification of thermal neutron fluence is caused by the neutron moderation produced by the dosimeter material. Fricke gel dosimeters in thin cylinders, with diameter not greater than 3mm, have proved to give good results for thermal neutron profiling. For greater accuracy of all results, a better knowledge of the dependence of gel dosimeter sensitivity on radiation LET is needed.


Assuntos
Terapia por Captura de Nêutron/instrumentação , Dosagem Radioterapêutica , Modelos Teóricos , Método de Monte Carlo
18.
Br J Radiol ; 88(1045): 20140392, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25257709

RESUMO

Proton and ion beams are radiotherapy modalities of increasing importance and interest. Because of the different biological dose response of these radiations as compared with high-energy photon beams, the current approach of treatment prescription is based on the product of the absorbed dose to water and a biological weighting factor, but this is found to be insufficient for providing a generic method to quantify the biological outcome of radiation. It is therefore suggested to define new dosimetric quantities that allow a transparent separation of the physical processes from the biological ones. Given the complexity of the initiation and occurrence of biological processes on various time and length scales, and given that neither microdosimetry nor nanodosimetry on their own can fully describe the biological effects as a function of the distribution of energy deposition or ionization, a multiscale approach is needed to lay the foundation for the aforementioned new physical quantities relating track structure to relative biological effectiveness in proton and ion beam therapy. This article reviews the state-of-the-art microdosimetry, nanodosimetry, track structure simulations, quantification of reactive species, reference radiobiological data, cross-section data and multiscale models of biological response in the context of realizing the new quantities. It also introduces the European metrology project, Biologically Weighted Quantities in Radiotherapy, which aims to investigate the feasibility of establishing a multiscale model as the basis of the new quantities. A tentative generic expression of how the weighting of physical quantities at different length scales could be carried out is presented.


Assuntos
Radiobiologia/tendências , Radiometria/tendências , Humanos , Dosagem Radioterapêutica , Eficiência Biológica Relativa
19.
Med Phys ; 41(11): 112105, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25370656

RESUMO

PURPOSE: Peripheral dose in radiotherapy treatments represents a potential source of secondary neoplasic processes. As in the last few years, there has been a fast-growing concern on neutron collateral effects, this work focuses on this component. A previous established methodology to estimate peripheral neutron equivalent doses relied on passive (TLD, CR39) neutron detectors exposed in-phantom, in parallel to an active [static random access memory (SRAMnd)] thermal neutron detector exposed ex-phantom. A newly miniaturized, quick, and reliable active thermal neutron detector (TNRD, Thermal Neutron Rate Detector) was validated for both procedures. This first miniaturized active system eliminates the long postprocessing, required for passive detectors, giving thermal neutron fluences in real time. METHODS: To validate TNRD for the established methodology, intrinsic characteristics, characterization of 4 facilities [to correlate monitor value (MU) with risk], and a cohort of 200 real patients (for second cancer risk estimates) were evaluated and compared with the well-established SRAMnd device. Finally, TNRD was compared to TLD pairs for 3 generic radiotherapy treatments through 16 strategic points inside an anthropomorphic phantom. RESULTS: The performed tests indicate similar linear dependence with dose for both detectors, TNRD and SRAMnd, while a slightly better reproducibility has been obtained for TNRD (1.7% vs 2.2%). Risk estimates when delivering 1000 MU are in good agreement between both detectors (mean deviation of TNRD measurements with respect to the ones of SRAMnd is 0.07 cases per 1000, with differences always smaller than 0.08 cases per 1000). As far as the in-phantom measurements are concerned, a mean deviation smaller than 1.7% was obtained. CONCLUSIONS: The results obtained indicate that direct evaluation of equivalent dose estimation in organs, both in phantom and patients, is perfectly feasible with this new detector. This will open the door to an easy implementation of specific peripheral neutron dose models for any type of treatment and facility.


Assuntos
Nêutrons , Radiometria/instrumentação , Radiometria/métodos , Radioterapia/métodos , Antropometria , Calibragem , Estudos de Coortes , Desenho de Equipamento , Humanos , Modelos Estatísticos , Neoplasias/diagnóstico , Neoplasias/diagnóstico por imagem , Neoplasias/radioterapia , Imagens de Fantasmas , Doses de Radiação , Radiografia , Dosagem Radioterapêutica , Análise de Regressão , Reprodutibilidade dos Testes , Medição de Risco
20.
Radiat Prot Dosimetry ; 161(1-4): 37-40, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24255174

RESUMO

NESCOFI@BTF is a 3-y project (2011-13) supported by the Scientific Commission 5 of INFN (Italy). The target is the development of neutron spectrometers similar to the Bonner spheres, in terms of response energy interval and accuracy, but able to determine the neutron spectrum in only one exposure. These devices embed multiple (10 to 30) thermal neutron detectors (TNDs) within a single moderator. Two prototypes, called SPherical SPectrometer (SP(2)) and cylindrical spectrometer (CYSP), have been set up. Whilst SP(2) has spherical geometry and nearly isotropic response, the CYSP has cylindrical geometry and is intended to be used as a directional spectrometer. Suitable active TNDs will be embedded in the final version of the devices. The resulting instruments could be used as real-time neutron spectrometers in neutron-producing facilities. This communication describes the design criteria, numerical analysis, experimental issues, state-of-the-art and future developments connected with the development of these instruments.


Assuntos
Nêutrons , Espectrofotometria/instrumentação , Espectrofotometria/métodos , Desenho de Equipamento , Itália , Método de Monte Carlo , Polietileno/química , Desenvolvimento de Programas , Doses de Radiação , Monitoramento de Radiação/instrumentação , Proteção Radiológica/métodos , Reprodutibilidade dos Testes
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