Gallium Arsenide Microstrip Detector and Pixel Detector Dlevelopmeiits

Recent developments in improved charge collection efficiency of GaAs pad detectors are described together with their radiation hardness to irradiation by neutron, proton and pions. While the resistance to neutron irradiation is satisfactory more susceptibility is found to charge particle irradiation. Test beam results from microstrip detectors tested in a 70GeV pion beam at CERN are also presented. Progress with GaAs pixel detectors is also reported.