Multi-Wire Proportional Counters

The photon-detection system is a high-pressure (5-Bar Xenon) titanium Multi-Wire Proportional Counter (MWPC) behind a coded mask system. The MWPC has an active area of 1800 cm and a detection efficiency of > 10% over the 5 150 keV range of sensitivity. The detector will be used... 

Multi-wire proportional counter for energy and 2D spatial resolution (From Saul 1994)... 

There are a wide array of detectors available for X-ray imaging. We have limited this discussion to two-dimensional X-ray detectors film, image plates, multi-wire proportional counters, and optoelectronic detectors. Other two-dimensional systems, such as directly bombarded, solid state X-ray detectors are also available, but are still in the early stages of development. 

Multi-wire proportional counters work by detecting the spatial position of X-ray in-... 

The multi-wire proportional counter has a number of advantages over film. It detects single quanta with very small noise levels, so this leads to a great improvement over film in terms of sensitivity. On average, exposures with a multi-wire proportional counter will take l/50th of the time of exposures on film. Intensity measurements are also far more accurate the reproducibility... 

Figure 14. A multi-wire proportional counter. Electrical pulses induced by the X-ray ionization avalanche are picked up on the cathode wires and are used to locate the X-ray s position.

The multi-wire proportional counter is an excellent device for accurate quantitative work. It has drawbacks, certainly in terms of expense and complexity, but commercial devices of a high standard are available. The multi-wire proportional counter is a detector for those who can afford the cost and need sensitive, quantitative X-ray detection. 

The analyzing magnet in conjunction with the multi-wire proportional chamber planes, was used to measure the momenta of charged particles. The shower counters and scintillation counters, installed after the iron absorbers, identified electrons and muons accordingly. After the introduction of a set of criteria, 320 examples of the decay (1) were observed. By imposing more strict criteria, from this number, 163 events were selected [3],... 

SC = single counter diffractometer MWPC = multi-wire proportional chamber. 

A different detection unit is the solid-scintillator proportional counter [6]. It consists of a scintillator with ultraviolet emission in a multi wire chamber filled with an organic vapor. The organic molecules are ionized by the ultraviolet photons and the resulting photoelectrons are detected in the multi wire chamber. A popular molecule in this aspect is TMAE (tetrakis (dimethylamino) ethylene). Figure 9.4 presents the spectral sensitivities of the detectors mentioned. 

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