Optimisation of Wedge and Strip Anodes

We describe the Wedge and Strip Anode (WSA) position read-out system and compare the performance of currently used WSAs with that of Resistive Disk Anodes (RDAs). We show that for small systems the WSA can outperform the RDA while for larger systems the RDA cannot be used at all due to size limitations. We discuss noise in WSAs and present a comprehensive optimisation scheme based on a model for the WSA capacitance [1] which is capable of reducing the electronic noise by a factor of up to 6 compared with current WSAs. We present capacitance, noise and position resolution measurements of several WSAs with active diameters of up to 200mm. We describe a simple technique for the manufacture of WSAs and use this to produce WAs on thin metallised polymer film as an alternative noise reduction method. We discuss a special low noise application of WSAs to spectroscopy. The conclusion is reached that in most cases RDAs can be advantageously replaced by WSAs.