Detectors construction

Station 6.2 brings together three techniques optimised for materials processing. These are ID SAXS/WAXS, X-ray diffraction and XAS (X-ray absorption spectroscopy). This will be a tuneable facility and equipped with state of the art detectors constructed along similar lines to the RAPID 2D detector for station 16.1. This will enable count rates of co. 10 MHz for both ID small and... 

Figure 10 shows the angular response of the detector. The 1461 and 2614 keV peak areas are relatively uniform as expected, but the source peak areas show a reduction in the 90 and 180 directions. This reduction is about 15% and can not be explained from the detector construction. The average data collection time was 7 hours. 

What distinguishes one alkali flame detector from the other is largely the way in which alkali is brought into the flame. The fact that the performance of the detector depends to a great extent on the physical and chemical structure of the alkali source may serve to explain many seemingly contradictory results. The recent, quite elaborate, review by Brazhnikov et al. (20) provides a good source of reference for different detector constructions. 

Materials that have to be used in the km3 detector construction must resist to an extremely hostile environment where pressure ( 300 bar at 3000 m depth), together with salinity, reduce the lifetime of most metals and alloys used in surface and shallow water applications. NEMO is designing and realising underwater vessels (junction boxes and other submarine containers) decoupling the two problems an outer vessel, made of glass epoxy, resistant to marine corrosion is filled with not-corrosive oil. The inner pressure resistant vessel, made of common steal and pressure resistant, will host fragile electronic components. Another crucial point for deep sea detectors installation is feasibility and reliability of underwater connections. NEMO is studying the possibility to... 

By 1975 the Ge(Li) detector had been supplanted by a newer, more rugged device the high-purity germanium detector. This germanium detector construction is produced without the lithium-drift compensation. Consequently, it is as impervious to warm-up as the Si(Li) detector. 

It is useful to extrapolate the cosmic ray components of the background in the deep KamLAND detector to shallower depths at which detector construction is more feasible. Most of the cosmic ray induced background comes firom neutrons with energies up to several hundred MeV produced by muon capture and spallation in materials surrounding the detector. Few experiments have been done that give detailed information on the... 

Existing liquid scintillator detectors constructed about 50 m.w.e. (20 m of rock) below the surface could detect 1 kt tests a few kilometers from a source and therefore could be useful for the first two applications. The utility of such a detector ultimately depends on trade-offs between cost and the desire by states for a non-intrusive local nuclear monitoring system. 

The result of these tests and calibrations at the different stages of the BPIX detector construction will be reviewed in the following. 

There is an excellent description of detector construction at http //www.ortec-online.com/detectors/photon/al l.htm. 

At very low levels, detectors constructed of selected low background materials are essential. Look for internal gamma shields between the detector and preamplifier, or a remote preamplifier. Obtain as much information from the manufacturer as possible on its behaviour. 

The Sensys DSC line is based on the Calvet detector construction. This construction is a three-dimensional array of thermocouples that surround tubular sample and reference holders. The array consists of 10 rings, each containing 12 thermocouples in series. The holders are long tubes that bisect a surrounding furnace. The unit can be operated in either a horizontal or a... 

Before starting to discuss concrete examples of detector construction, it is instructive to examine some of the properties which are important for their application. The most important in this respect are their ... 

Besides the described mechanical lifting of the electrode, hydraulic and pneumatic systems have been further employed and a chromatographic detector constructed [72]. 

The density of charge of the soil components was measured by a particle charge detector constructed by Miitek, FRG. The suspension was filled into a cylindrical testing apparatus and a large fraction of the solids was adsorbed on its wall. As a function of pH and characteristics of the soil constituents these solids are charged except at... 

For more sensitive detection of low incident powers, bolometers and Golay cells are used. A bolometer is a detector constructed from a material with a large temperature coefficient a = (dR/dT)/R of resistance R. If a constant current I is fed through R (see Fig.4.68), the incident power P which causes a temperature increase aT produces an output signal... 

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