[en] Only the knowledge of the convective-diffusive heat transport phenomena in laminar and turbulent MHD flows enables an adequate design of heat transfer units (e.g. liquid metal cooled fusion blankets) or the development of MHD controlled processes. This report presents an experimental and numerical study of the heat transfer in a flow of a rectangular duct with electrically conducting walls exposed to an uniform transverse magnetic field B, oriented parallel to two walls. The heat flux q produced by a radiation heater is perpendicular to B. Both, the integral quantities (pressure drop, Nusselt number Nu) as well as the local ones (temperature at fluid-wall interface, velocity, temperature in the fluid) are measured. The parameters investigated are: Hartmann number 0 ≤ M ≤ 5000, Reynolds number 0 ≤ Re ≤ 1.3 . 10⁵ and Peclet number 0 ≤ Pe ≤ 2900. The measured pressure drop agrees with the analytic one for two-dimensional laminar duct flows for nearly all parameters. Only for M ≤ 350 and Re ≥ 7 . 10⁴ higher values are obtained. The critical Reynolds number Re_crit where the pressure drop of the MHD flow is negligibly small compared with an ordinary hydrodynamic flow (OHD) is found to be given in the investigated configuration by the relation Re_crit 100 . M. Regarding the velocity distribution and the temperature distribution within the duct, which are measured using a temperature-potential probe (TEMPO), an excellent agreement between experiment and calculation is found for laminar MHD flows. The wall Nusselt number of the MHD flow is due to the high velocity jet at the walls parallel to B about 30% higher compared to an ordinary hydrodynamic flow

[en] With the measuring equipment wear particles in oil as transport medium coming from radioactively labelled parts, e.g. motor equipment, are detected. As measuring detector a NaI(Tl) scintillation crystal is used which is centrally positioned in a flow chamber. Th oil containing the wear particles enters the flow chamber tangentially at its upper end and streams spirally around the detector. At the lowest point of the funnel-shaped bottom it leaves the chamber again, sedimentation of wear particles and clearance volumes are thus avoided. The flow chamber is surrounded by ring-shaped lead shields. In one of the rings there is a radial bore for holding a calibration sample with which the detector can be calibrated. (DG)

No abstract available

[en] Thin windows for x-ray spectrometer flow counters can be produced by stretching unorientated polypropylene film. A piece of the stretched film is clamped into a holder and pressed onto a copper ring made from thin copper sheeting. The mounted window is then suspended in a high vacuum coating unit and flashed with aluminium to a thickness of approximately 20 nm. (author)

[en] Selection of the nuclear emitters, especially the β-emitters like tritium or ¹²⁵J, takes place in a flow counter. The gaseous radionuclides are added to the carrrier gas containing air. The output pulses of the counter are discriminated according to pulse shape or height or range. In pulse discrimiation a zero passage signal is obtained according to the principle of double-delay-line pulse forming, the time difference between reflection instant and zero passage being determined. For range discrimination where the output pulses are combined channelwise according to their rise time, there is formed the difference between the pulse rate of one channel and the pulse rate of another channel multiplied by a constant factor. The counter may be used as air monitor. (DG)

No abstract available

[en] Radiotracer techniques can be used to measure accurately both gas and liquid flow rates under operating conditions in a wide range of flow systems. They are ideally suited for calibrating flow meters as well as for measuring unmetered flows in industrial plants. Applications of these techniques range from measuring the flows of fuels and process fluids for energy and mass balance studies to measuring the flows of liquid and airborne effluents for pollution control. This report describes the various radiotracer techniques which can be used to measure fluid flows. The range of application and inherent accuracy of each technique is discussed

[en] With proportional flow counters low-level tritium can be measured with small counter volumes. The air is mixed with a counting gas, which is usually methane. It is possible to add about 20 to 30% of air to methane without a serious loss in good counter characteristics. In this paper are presented the properties of proportional counter techniques in monitoring airborne tritium. (author)

[en] The radioactive organic compounds are taken through a heating furnace, before they reach the flow counter. The heating furnace consists of a quartz reaction tube which has a heating wire wound around it and which is surrounded at a distance by a further quartz tube. Both the coaxial horizontal quartz tubes are surrounded by a metal case. The intermediate space is filled with ceramic wool for insulation purposes. (DG)

No abstract available