Preliminary results on a position sensitive parallel plate avalanche counter with a distributed constants delay-line cathode

A position sensitive parallel plate (PSPP) stop detector for heavy ions with an active area of 70 × 76 mm ² has been developed. The cathode is a printed circuit board with parallel strips which form a delay-line. The position resolution is better than 1 mm in the x direction (orthogonal to the strips) and better than 2 cm in the y direction (along the strips). The anode time resolution is about 300 ps fwhm.