Results from prototypes of environmental and health alarm devices based on gaseous detectors operating in air in counting mode

International audienceWe have developed and successfully tested two prototypes of detectors of dangerous gases based on wire-type counters operating in air in avalanche mode: one is for radon (Rn) detection whereas the other one is for the detection of gases with an ionization potential less than the air components. Due to the operation in pulse counting mode these prototypes have sensitivities comparable to (in the case of the Rn detector) or much higher than (in the case of the detector for low ionization gases) the best commercial devices currently available on the market. We believe that due to their high sensitivity, simplicity and low cost such new detectors will find massive applications. One of them, discussed in this paper, could be the on-line monitoring of Rn for the prediction of earthquakes

The spherical drift chamber for x-ray imaging applications

Properties of proportional chambers with spherical drift spaces have been investigated. An experiment of X-ray diffraction in crystals shows that an accuracy of 0.5 mm, at 20 degrees inclination with respect to the axis of the chamber, can be obtained with 4 cm of drift length. Such chambers have many applications: X-ray diffraction patterns, pin-hole imaging, angular distributions of cascades of X- rays in nuclear physics, etc. (4 refs)