No abstract available

[en] A method for subcritical verification of BWR shut-down margin (SDM) has been developed. The new procedure saves time on the critical path to reactor startup, is safer and provides a SDM verification of the whole core. The measurements rely on the newly installed Wide Range Neutron Monitor system which locally performs very well also for weak neutron sources. The method, based on simple point-kinetics, has been validated in measurements over several cycles in three BWRs. The minimum SDM of the core is estimated by a statistical on-line evaluation of the measured data on a confidence level commensurate with the safety impact of not meeting the single failure criterion. (author)

[en] Full text: The International Atomic Energy Agency has two statutory safety functions: (a) establishment of standards of safety for protection of health and minimisation of danger to life and property, and (b) the provision for the application of these standards to its own operations or at the request of a Member State. The Agency's Occupational Radiation Protection Programme aims at harmonising occupational radiation protection infrastructures for the control of radiation exposure of workers and for optimising radiation protection in situations of exposure due to external radiation and intakes of radionuclides from both artificial and natural sources of radiation. Under its Regular and Technical Co-operation Programmes, the Agency has been assigning high priority to both the establishment of safety standards for 'labour conditions' and for the application of these standards through, inter alia, direct assistance under the Technical Co-operation (TC) Programme, the rendering of services, the promotion of education and training, the fostering of information exchange and the co-ordination of research and development. The purpose of this paper is to describe the IAEA Occupational Radiation Protection Programme, including the production of Safety Standards, Safety Reports and other safety related material, the Information System on Occupational Exposure (ISOE), the Occupational Radiation Protection Appraisal Service (ORPAS), related TC projects and Intercomparison exercises. (author)

[en] An electrochemical cell has been constructed for in situ neutron diffraction studies of lithium-insertion/extraction processes in electrode materials for Li-ion batteries. Its key components are a Pyrex tube, gold plated on its inside, which functions as a current collector, and a central lithium rod, which serves as the negative electrode. The device is demonstrated here for a neutron diffraction study of lithium extraction from LiMn₂O₄: a mechanical Celgard separator soaked in the electrolyte surrounds the lithium electrode. The LiMn₂O₄ powder, mixed with electrolyte, occupies the space between separator and current collector. (orig.)

[en] At the low temperatures of cool carbon star atmospheres polyatomic molecules form. Most abundant of these for the temperature range 2500 - 3000 are HCN and C₂H₂. These molecules have numerous bands at wavelengths where a major part of the stellar flux is transported. This opacity could therefore be of great importance when constructing models for cool carbon star atmospheres, but has not been included in earlier models. (Auth.)

[en] Monte-Carlo simulations have been performed for the purpose of investigating the energy discriminating feature of a semiconductor hybrid pixel detector at diagnostic energies. Part of the evaluation was performed using synthetic images obtained from the simulated data. (orig.)

[en] A furnace is described for in situ X-ray diffraction studies, in transmission mode, of structural changes in electrode materials for Li-ion (polymer) batteries in the ambient to 300 C temperature range. The method exploits the thin flat-cell geometry of the lithium-polymer battery concept. The flat sample is able to oscillate about a horizontal axis in its own plane in the X-ray beam, to provide better averaging during the diffraction experiment. The use of the device is demonstrated in a study of lithium intercalation in graphite (a commonly used anode material in lithium-ion batteries) during electrochemical cycling and storage at 70 C. (orig.)

[en] Two-pion production reactions in proton-proton collisions have been studied using the PROMICE/WASA detector and an internal cluster gas-jet target at the CELSIUS storage ring in Uppsala. The total cross sections for the pp →ppπ⁺π^-, pp →ppπ⁰π⁰ and the pp →pnπ⁰π⁺ reactions are presented at beam energies ranging from 650 to 775 MeV. An isospin analysis of the amplitudes involved in these three reactions indicates that the excitation of the N^*(1440) followed by direct two pion emission can be the most important amplitude when allowed. However, large contributions from other production mechanisms must also be prevalent to explain the large pp →pnπ⁰π⁺ cross section. The data are compared to an extensive model including non-resonant as well as resonant production via N^* and Δ excitation

[en] A pixel readout chip for medical X-ray imaging has been developed. It is to be used in a hybrid pixel detector, where it is connected to a semiconductor sensor. A single chip consists of 992 square pixels arranged in 31 columns and 32 rows. Each pixel has a side of 270 μm and comprises a preamplifier, shaper, discriminator and two counters. The readout chip operates as a photon counter. The implementation of two counters in every single pixel cell is a design solution that makes it possible to acquire two images very close in time and under different conditions. The readout chip has been characterised in the absence of a sensor by using charge injection. Results are presented on basic functionality, threshold dispersion and the capability to perform photon counting

[en] A semiconductor hybrid pixel detector for dynamic X-ray imaging is developed. The detector, called DIXI, consists of a semiconductor sensor mounted onto a readout chip. A detector module with a 500 μm silicon sensor is currently being assembled with the use of anisotropic conductive film as interconnection between the sensor and the readout chip. The basic building block of the detector is 1 cm² in size and consists of 992 square pixel cells arranged in 31 columns and 32 rows. The pixels have a side of 270 μm. The readout chip is capable of performing photon counting and has an externally adjustable threshold. The readout chip has been characterised by charge injection in the absence of a sensor. The threshold dispersion is measured to 365 e^- for hole collection. Even if the chip was not originally designed for electron collection a threshold dispersion of 1650 e^- has been achieved. Two counters are implemented in every single pixel cell and the threshold can be changed from one image to the next in order to select different parts of the X-ray spectrum