[en] Three factors which affect the outcome of any immunisation schedule designed to produce antisera for radio-immunoassay, the antigen, the method of immunisation and the choice of animal are considered. Several factors concerning the nature of the antigen are dealt with, for example, the molecular size and immunogenicity of the antigen. It is noted that the larger polypeptide and proteins are sufficiently immunogenic to elicit a useful antibody response alone and that whilst substances with molecular weights of less than 2000 may produce a response alone they will probably produce a better one if they are conjugated (chemically coupled) to a much larger molecule. The method of immunisation is discussed including a consideration of the use of adjuvant and the route and timing of injections. It is noted that antisera showing the relevant properties for radio-immunoassay are rarely produced without emulsification of the immunogen in Freund's adjuvant although this is not an absolute requirement for antibody production. Data are presented comparing the intramuscular and multiple intradermal routes of injection. The results, however, fail to demonstrate any major advantage for either method although the latter may be more economical, producing high titre antisera with relatively small amounts of immunogen. Because of their convenience rabbits are generally the first choice of animal for raising antisera for radioimmunoassay although guinea pigs, chickens and sheep have been used successfully in many cases

[en] An atomic beam polarimeter for measurement of the hyperfine population numbers and the absolute polarization of thermal atomic hydrogen (H) and deuterium (D) beams is described. The principle of measurement and the method of calibration are given. The polarimeter measures the 4 (6) relative hyperfine population numbers of a thermal H (D) beam in the region of 10¹³ atoms/s to an absolute error of less than 0.01. The polarimeter has been in continuous operation with the internal polarized hydrogen and deuterium gas target used in the HERMES experiment at DESY since 1996. (orig.)

[en] An immunoradiometric assay system for HBsAg has been developed utilising an antibody coated tube in which all the intermediate washing and reagent dispensing operations are performed automatically in a purpose built machine. The system has been evaluated by two blood transfusion service laboratories and appears to overcome the potentially high operator associated false positive rate often seen in tube assays of this type. The sensitivity of the system was found to compare favourably with the other assays in use in those laboratories. (author)

No abstract available

No abstract available

[en] France intends to build a sodium-cooled fast reactor (SFR) prototype called ASTRID - for Advanced Sodium Technological Reactor for Industrial Demonstration - in preparation of the industrial deployment of such sodium fast reactors in the future. Its mixed oxide (MOX) fuels will be produced by a new industrial-scale core fabrication facility named AFC1, which is still under development. The fabrication process of MOX fuel is based on powder metallurgy processes. The UO₂ and PuO₂ mixture is pelletized and then sintered at about 1700°C under reducing atmosphere of Ar/4%H₂/H₂O. Fuel has to be in compliance with specifications. In particular, the O/M (atomic oxygen to metal ratio) has to be hypostochiometric and close to 1.97 and the microstructure has to be dense, around 95 %Th.D. The O/M and microstructure can affect numerous properties of the fuel during operation including thermal conductivity, mechanical properties and fuel-cladding interactions. To meet these requirements, better knowledge of sintering at laboratory and industrial scale is needed. An original analysis method has been therefore developed for a better understanding of the O/M ratio evolution and densification mechanisms during the sintering step. By coupling a dilatometer with an oxygen zirconia probe, it is possible to identify the different redox phenomena and to plot the evolution of the O/M of the oxides versus time during the densification process. This innovative method is helpful to understand how gas and fuel interact. Whereas it was difficult to predict a precise final O/M, this new method produces the expected ratio every time. This paper highlights the different final O/M values and microstructure, particularly in terms of microcracking, obtained during sintering in a continuous industrial or laboratory furnace. The impact of the evolution of moisture content in the gas is explained. Based on these results, a multiphysic model is being built to obtain a better knowledge of the interaction with MOX fuel and the surrounding atmosphere. Then, some recommendations can be made about the sintering atmosphere to improve industrial cycles and optimize fuel characteristics in order to obtain an O/M as close as possible to the target value and the right microstructure. (author)

[en] France intends to build a sodium-cooled fast reactor (SFR) prototype called ASTRID - for Advanced Sodium Technological Reactor for Industrial Demonstration - in preparation of the industrial deployment of such sodium fast reactors in the future. Its mixed oxide (MOX) fuels will be produced by a new industrial-scale core fabrication facility named AFC1, which is still under development. The fabrication process of MOX fuel is based on powder metallurgy processes. The UO2 and PuO2 mixture is pelletized and then sintered at about 1700°C under reducing atmosphere of Ar/4%H2/H2O. Fuel has to be in compliance with specifications. In particular, the O/M (atomic oxygen to metal ratio) has to be hypostochiometric and close to 1.97 and the microstructure has to be dense, around 95 %Th.D. The O/M and microstructure can affect numerous properties of the fuel during operation including thermal conductivity, mechanical properties and fuel-cladding interactions. To meet these requirements, better knowledge of sintering at laboratory and industrial scale is needed. An original analysis method has been therefore developed for a better understanding of the O/M ratio evolution and densification mechanisms during the sintering step. By coupling a dilatometer with an oxygen zirconia probe, it is possible to identify the different redox phenomena and to plot the evolution of the O/M of the oxides versus time during the densification process. This innovative method is helpful to understand how gas and fuel interact. Whereas it was difficult to predict a precise final O/M, this new method produces the expected ratio every time. This paper highlights the different final O/M values and microstructure, particularly in terms of microcracking, obtained during sintering in a continuous industrial or laboratory furnace. The impact of the evolution of moisture content in the gas is explained. Based on these results, a multiphysic model is being built to obtain a better knowledge of the interaction with MOX fuel and the surrounding atmosphere. Then, some recommendations can be made about the sintering atmosphere to improve industrial cycles and optimize fuel characteristics in order to obtain an O/M as close as possible to the target value and the right microstructure. (author)

[en] A report is presented on the production and irradiation procedure used to prepare 3 litres of ammonia beads for the European Muon Collaboration (EMC) polarised target. The initial studies, consisting of a Monte Carlo simulation of the irradiation process and tests using thermoluminescent crystals, are described. The apparatus used and its performance in the LINAC beam at Bonn University will be given along with the problems encountered, such as explosions and beam steering. Tests have been carried out on the first samples of ammonia beads irradiated and the results from polarising small amounts of these samples of differing exposure times is presented. (orig.)

[en] Published in summary form only

[en] We have built a polarized proton and deuteron target for experiments using intense high-energy electron beams. This system exploits dynamical nuclear polarization of irradiated ammonia in a 5 T magnetic field at temperatures near 1 K. We describe the various features and the performance of the target