A Fast High Resolution Beam Hodoscope Using Silicon Microstrip Detectors

Silicon detectors with a parallel strip pattern of 50 ¿m periodicity are used for the detection of high energy particles. Four detectors are mounted together in a beam hodoscope, which permits a measurement of the particle trajectory with a precision better than 20 ¿m. To each strip is connected a bipolar current sensitive preamplifier which provides a signal, shorter than 20 ns. It is shown that an optimal signal/noise ratio can be obtained if the signal is kept short throughout the signal processing chain. The noise after transmission over 100 m is 1300 electrons r.m.s. With such a hodoscope single particle detection is possible for intensities in the range 108-109 cm-2 s-1, and when used as a vertex detector, the parallel signal processing enables good particle separation in high multiplicity events.