SVX/silicon detector studies

Abstract

AC coupled silicon detectors, being used for the D/spl phi/ upgrade, may have substantial voltage across the coupling capacitor. Failed capacitors can present /spl sim/50 V to the input of the SVX, Silicon Vertex, device. We measured the effects that failed detector coupling capacitors have on the SVXD (rad soft 3 /spl mu/m), SVXH (rad hard 1.2 /spl mu/m), and SVXIIb (rad soft 1.2 /spl mu/m) amplifier/readout devices. The test results show that neighboring channels saturate when an excessive voltage is applied directly to a SVX channel. We believe that the effects are due to current diffusion within the SVX substrate rather than surface currents on the detectors. This paper discusses the magnitude of the saturation and a possible solution to the problem.