Journal of Radioanalytical and Nuclear Chemistry最新文献

Experimentally ensuring the quality of neutron beam before patient treatment is a topic of central importance for a boron neutron capture therapy (BNCT) facility. The procedure of beam quality assurance currently adopted at THOR-BNCT lacks a direct indication related to the energy distribution of neutrons. A new device based on multiple activation foils was therefore proposed to provide a quick confirmation of the unchanged neutron spectrum before patient irradiation. The device’s responses to the THOR-BNCT neutron beam are presented. A series of experimental tests were repeated to establish the baseline performance of the device, and further numerical simulations were conducted to determine its sensitivities to various perturbations in the reference spectrum. To increase the rigorousness of beam quality assurance by supplementing additional information about neutron spectrum, the device has been suggested to assist the role of Au/Cu activation foils in the current procedure as and when required.

Hydrogen generation was obtained with homogeneous n-C₆H₁₄, 88.5% n-C₆H₁₄+11.5% H₂O, 50% n-C₆H₁₄+50% H₂O and 11.5% n-C₆H₁₄+88.5% H₂O and heterogeneous Al₂O₃+n-C₆H₁₄, Al₂O₃+88.5% n-C₆H₁₄+11.5% H₂O, Al₂O₃+50% n-C₆H₁₄+50% H₂O and Al₂O₃+11.5% n-C₆H₁₄+88.5% H₂O systems. Hydrocarbons (methane, ethane, propane, butane, pentane, and hexane) and other organic molecules (methanol, acetaldehyde, and acetic acid) were also used for optimization. The activation energies were 3.50 and 3.74 kJ/mol for Al₂O₃+n-C₆H₁₄ and Al₂O₃+C₆H₁₄+H₂O systems. Maximum hydrogen produced was 54.0×1017 molecules/g.

The present study reports the terrestrial gamma radiation exposures in dwellings in Makum Coalfield, India, using a Micro-R Gamma Survey Metre. The geometric means (GMs) of indoor and outdoor gamma dose rates were found to be 150.3 ± 7.4 nGy h⁻¹ and 129.2 ± 6.6 nGy h⁻¹, respectively, which are considerably higher than the global population-weighted average of 84 nGy h⁻¹ and 59 nGy h⁻¹, respectively. The estimated GMs of annual effective dose equivalents and excess lifetime cancer risks were also found to be substantially higher than the global recommended values of 0.48 mSv y⁻¹ and 1.45 × 10^–3, respectively.

The Centers for Disease Control and Prevention (CDC) Radiation Laboratory’s primary mission is to provide laboratory support for an effective and efficient response to public health radiological emergencies. The laboratory has developed methods for several radiological threat agents, including Iridium-192 (Ir-192). Ir-192 can be analyzed via its gamma energy through analytical methods such as High Purity Germanium (HPGe) and its beta energy through Liquid Scintillation Counting (LSC). In this work, we present and compare HPGe and LSC rapid response methods for Ir-192 quantification. Both methods show the reasonable results and can be used in emergency situations.

The excitation functions of (^{nat})Mo((alpha), x)(^{97})Ru and (^{nat})Mo((alpha), x)(^{103})Ru reactions in the energy range of 10–22 MeV are determined using the stacked foil activation technique and offline (gamma)-ray spectrometry. The correction for (gamma)-self attenuation is performed in the present measurement. The theoretical predictions of cross-section for (^{nat})Mo((alpha), x)(^{97})Ru and (^{nat})Mo((alpha), x)(^{103})Ru reactions are calculated by TALYS. The results of the experiment are compared with the existing cross-section data available in the EXFOR database and different level density models by TALYS code. The uncertainty propagation in the measured cross-sections and correlation matrix using covariance analysis has been studied in this work.