Noise determination in silicon micro strips

We report the study of amplifier noise on silicon micro strip detectors. We have used a fast, low noise amplifier-comparator VLSI chip with 22 ns shaping time developed for the LHC to determine the noise at the pre-amp as a function of strip length and strip geometry, i.e., interstrip capacitance and ohmic strip resistance. In addition, we have tested the noise in irradiated detectors. We have compared the results with simulations using SPICE.