Design and properties of position-sensitive proportional counters using resistance--capacitance position encoding

The construction and signal processing methods of several experimental gas-filled, position-sensitive proportional counters (PSPCs) using resistance--capacitance (RC) position encoding are described, and guidelines for the design and operation of these counters are given. Using these guidelines, we were able to improve the spatial resolution and shorten the signal processing time; for example, the intrinsic spatial uncertainty in the position measurement was reduced to 28 μ FWHM for alpha particles and 100 μ FWHM for low-energy x rays (2--6 keV). Also, the signal processing time was reduced to 0.6 μsec without seriously degrading the spatial resolution. These results have widened the field of application of the RC position encoding method for position measurements of low-energy photons, neutrons, and charged particles in a wide variety of nuclear physics experiments, in nuclear medicine imaging, and in low-dose, medium-resolution radiography. (AIP)