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Abstract: A description of neutron detector with Si diode and 6LiF neutron converter is presented. Reasons for use of an air gap between the Si diode and the neutron converter are given. To demonstrate the quality of the detector, pulse height spectra have been measured on the epithermal neutron beam of the LVR-15 research reactor in different conditions. The results have been compared with activation method measurements. [Copyright &y& Elsevier]

Abstract: The epithermal neutron beam of the LVR-15 reactor provides the appropriate conditions for varied BNCT activity. The principal parameters have been frequently determined. The following detectors have been used for the measurement: set of activation monitors of different nuclides irradiated in free beam and in the water phantom, Si semiconductor detector with 6LiF converter, twin ionization chambers, thermoluminescence dosimeters, gel dosimeters used for imaging of separate part of dose, neutron spectrometer of Bonner type. Obtained results of measured parameters are presented in the paper. [Copyright &y& Elsevier]

Abstract: Fricke gel dosimeters in the form of layers are suitable to reconstruct bidimensional distributions of the absorbed dose; in accordance with their chemical composition and applying suitably developed algorithms, they can provide dose images of the different radiation components in a BNCT field. After the description of the applied method, this work presents the results obtained at the epithermal column of the BNCT facility at the NRI in Řež (CZ). The measured dose distributions are shown in comparison with data taken by means of other dosimeters thermoluminescence dosimeters (TLDs) and with calculations carried out with the Monte Carlo code MCNP5. The agreement with the results obtained by means of the different techniques is satisfying. [Copyright &y& Elsevier]

Dosimetry measurements have been carried out at the epithermal neutron beam of LVR-15 reactor (Řež) moderated by a polyethylene disk placed through the collimator exit. The spatial distributions of thermal neutron fluence rate and of gamma and fast neutron dose rates have been attained. The contributions to the dose of the radiation field components have been assessed with Fricke-gel-layers, by pixel-to-pixel elaboration of the light transmittance images of samples having different isotopic composition and with thermoluminescence detectors, by analysing the shape of the glow curve. An analogous experiment has been carried out at the thermal column HK1 of the same LVR-15 reactor, aimed at neutronography research. Good consistency of all results was obtained. [ABSTRACT FROM AUTHOR]

Abstract: Boron neutron capture therapy (BNCT) is a cancer radiotherapy that uses epithermal and thermal neutron beams. The determination of the absorbed dose in healthy tissue, separating the various dose contributions having different radiobiological effectiveness (RBE) is of great importance for therapy planning. However, a standard code of practice has not yet been established because suitable methods for dosimetry in BNCT are still in progress. A study about the characterization of the epithermal column of the LVR-15 research reactor in Řež (CZ) has been performed, in particular concerning the fast-neutron dose. This dose is not negligible and its determination is important owing to its high RBE. Fast-neutron and photon dose distributions in a water phantom have been measured by means of Fricke gel layer dosimeters. Even if gel layer dosimetry is not yet standardized, it is presently the only method for obtaining images of each dose contribution in BNCT neutron fields. The results were compared with values measured with thermoluminescence detectors, twin ionization chambers data taken from literature and Monte Carlo simulations. [ABSTRACT FROM AUTHOR]

Abstract: Suitable dosimeter methods have been proposed and tested, to measure the different dose contributions in small phantoms exposed to epithermal/thermal neutron beams designed for BNCT. One method is based on Fricke-gel dosimeter in small tubes of 2.8mm of external diameter, that allow determining profiles of gamma dose and of boron dose. The other method is based on the use of TLD-700 chips, from whose answer the contribution of thermal neutrons is subtracted by means of appropriate parameters of the glow curve. [Copyright &y& Elsevier]

Abstract: Gamma and fast neutron dose spatial distributions have been measured at the collimator exit of the epithermal neutron beam of LVR-15 reactor (Řež). Measurements were performed by means of optically analyzed Fricke-gel-layer detectors. The separation of the two dose contributions has been achieved by suitable pixel-to-pixel elaboration of the light transmittance images of Fricke-gel-layer detectors prepared with water and heavy water. [Copyright &y& Elsevier]

Abstract: Horizontal channel with epithermal neutron beam at the LVR-15 research reactor is used mainly for boron neutron capture therapy. Neutron fluence depth profiles in a water phantom characterise beam properties. The neutron fluence (approximated by reaction rates) depth profiles were measured with six different types of activation detectors. The profiles were determined for thermal, epithermal and fast neutrons. [Copyright &y& Elsevier]