RESUMEN
Neutron capture therapy (NCT) is a radiotherapeutic technique that is designed to utilize the neutron capture reaction and damage the tumor cells through the energy release from the reaction. Nuclear reactors are typically utilized in this therapy because of the high neutron fluence rate that can be achieved. There has been minimal work to evaluate the effectiveness of neutron generators in NCT. This work presents the preliminary simulation results of utilizing of a deuterium-deuterium generator in boron neutron capture therapy. MCNP 6.1 was used to model the detailed geometry of the neutron generator and the phantom. Neutron moderators and photon shielding were used to optimize the neutron fluence rate in the tumor and decrease the photon dose in the phantom respectively. The study showed that a good localization of the neutron dose can be achieved in the tumor area with a reduction of the photon dose in the surrounding areas.
Asunto(s)
Terapia por Captura de Neutrón de Boro/métodos , Neoplasias/radioterapia , Neutrones , Humanos , Fantasmas de Imagen , FotonesRESUMEN
Monitoring drinking water, including bottled water, is imperative to safeguarding public health especially where bottled water consumption is high like in the United Arab Emirates (UAE). In this study, radionuclide activity levels of Tritium (3H) and Potassium (40K) were assessed in various brands of bottled water marketed in UAE. Activity level data was used to calculate the annual effective doses (Ed) for different age groups, and the excess lifetime cancer risk (ELCR) for adult males and females in the UAE population. Activity levels for both radionuclides were below the allowable maximum guideline values specified by local and international standards. Calculated total age dependent ingestion doses revealed that adults and lactation age groups received the highest effective ingestion doses. Adult males exhibited a higher ELCR for both isotopes, compared to females. Nonetheless, total radioactive dose for each water brand (0.91-1.47 µSv/yr) as well as for each population group were well below the recommended annual reference dose level of 100 µSv set by World Health Organization. Therefore, bottled water in the UAE is safe from the radiological aspect for investigated radionuclides, and poses no significant radiological exposure and health risk to the public.
Asunto(s)
Agua Potable/análisis , Radioisótopos de Potasio/análisis , Tritio/análisis , Contaminantes Radiactivos del Agua/análisis , Adulto , Exposición Dietética , Ingestión de Alimentos , Femenino , Humanos , Masculino , Radioisótopos/análisis , Medición de Riesgo/métodos , Emiratos Árabes UnidosRESUMEN
Neutron generators are an excellent tool that can be effectively utilized in educational institutions for applications such as neutron activation analysis, neutron radiography, and profiling and irradiation effects. For safety purposes, it is imperative that appropriate measures are taken in order to minimize the radiation dose from such devices to the operators, students and the public. This work presents the simulation and measurement results for the neutron and photon dose rates in the vicinity of the neutron generator installed at the University of Sharjah. A very good agreement is found between the simulated and measured dose rates. All of the public dose constraints were found to be met. The occupational dose constraint was also met after imposing a 200 cm no entry zone around the generator room.
Asunto(s)
Neutrones , Exposición Profesional/análisis , Aceleradores de Partículas , Fotones , Exposición a la Radiación/análisis , Protección Radiológica/métodos , Diseño de Equipo , HumanosRESUMEN
A study was performed to enhance the neutron moderation and investigate the response of a landmine detection system based on measuring backscattered neutrons with a (3)He detector. Parameters affecting the system's response were simultaneously optimized to improve the sensitivity of the detection system. The optimized sensitivity of the detection system was analyzed for different horizontal and lateral positions of a landmine.
RESUMEN
In the present work, a boron lining is added to a NaI detector assembly to study the possibility of combining both the C/O tool and the thermal neutron porosity tool in one tool, both of which are commonly used tools in oil well logging. The combined tool proposed in this paper was modeled with the general purpose Monte Carlo N-particle (MCNP) transport code. The simulation results show a good porosity sensitivity (especially to low porosity values). The results also show a great reduction in the neutron flux incident on the detectors and consequently the reduction of detector activation by thermal neutrons.