A Parallel Plate Avalanche Chamber with a Resistive Germanium Anode and a Two Dimensional Read-Out

A novel type of parallel plate counter with a resistive anode and a two dimensional read-out is presented. The anode is made of a thin germanium layer with a sheet resistivity ¿ 1 M¿/¿ and the cathode is made of aluminized mylar 5 ¿m thick. The anode is transparent to the fast impulse due to the collection of the multiplication electrons. A chessboard of "pads" placed behind the anode plane is used to obtain the positional information. The detector and the read-out system are physically and logically separated. The device is continuous, homogenous self-triggering and can operate at a rate of 106 particles/s. A spatial resolution ¿ 50 ¿m for both coordinates has been measured.