High-resolution, two-dimensional focal-plane detectors for intermediate-energy heavy ions

A large-area, high-resolution two-dimensional position-sensitive gas detector has been developed for intermediate-energy heavy ions. The x position information is obtained by a multicathode method, and the y position is determined by measuring the drift time of electrons. This detector has no left-right ambiguity and no dead layer in the sensitive area, resulting in a detector system which is thin and homogeneous in the whole sensitive area. The overall position resolution of 0.22 mm and 0.40 mm (FWHM) were obtained for the x and y directions, respectively. This detector system has been shown to be very useful for high-resolution heavy ion experiments at intermediate energies