Abstract: A two-dimensional proportional counter for position sensitive measurement of ionizing radiation in one plane comprises a counting chamber, in which a wire anode grid and at least one wire cathode grid are fastened spaced apart from one another and orthogonal to one another. The wires of these grids are connected directly to the windings of a continuous delay line to which the signals are fed for evaluation. The delay line has a continuous capacitor strip on its top. The dimensioning of the capacitor strip and of the other characteristic parameters of the delay line are slected such that the spacing of the grids from one another can be decreased to values below 2 mm, thus attaining a substantial increase in positional resolution, withou substantial impairment by the delay line of the form and amplitude of the pulses produced.

Abstract: This invention provides a high-resolution, position-sensitive, proportional-counter for ionizing radiation emanating from a surface source of ionizing radiation. There is provided a counting chamber means having an open entrance window on one side of and spaced from the source of ionizing radiation, and an anode counting wire on the other side of the open entrance window. Also, there is provided a counter wall cathode, having a delay line read-out opposite to the entrance window and spaced from the anode. A means, including several orifices for flushing a counting gas through the counting chamber means and out of the open entrance window between the source and the open entrance window, produces a stabilizing counting gas layer that does not mix with the surrounding air. This prevents the sample from being completely surrounding air. This prevents the sample from being completely enclosed so as to be charged up electrostatically.