A modular system of 250 preamplifiers and shaping amplifiers is being built to read out an array of silicon strip detectors. The detectors form a telescope which is used to study the breakup reactions of heavy ions in vacuum. A charge sensitive preamplifier connected to each strip amplifies the signal before it is passed to the second stage of amplification and shaping. An ADC converts the final signal to a digital form before processing by a computer, where information on particle identity, scattering direction and energy is extracted. The preamplifiers have been designed as thick-film hybrids in order to achieve the high circuit density required in the vacuum chamber. The hybrids plug into a mother-board from which twisted-pair cables carry the signals to the shaping amplifiers outside the chamber. The shaping amplifiers are surface-mounted boards, plugged into a Eurocard to which the cables are attached. The amplifiers feature three stages of shaping and a gain which can be adjusted by changing resistor packages on the Eurocard. The linearity of the amplifiers is better than 0.1% for the outputs up to 10 V, with a peaking time of 1 μs. The output noise is 1.0 mV rms at maximum gain, equivalent to 500 electrons rms in the detector.
|Number of pages||7|
|Journal||Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment|
|Publication status||Published - 1 Mar 1990|