Speaker
Dr
Michael Karagounis
(Universitaet Bonn)
Description
An ASIC capable of counting individual hits on a silicon microstrip
detector used in a Compton polarimeter has been developed. Laser
photons backscattered off an incident high-energy electron beam in
the 3.5GeV electron stretcher ring ELSA at Bonn university are pair
converted in a lead convertor and then detected on a silicon strip
sensor. The sensor is read out by a mixed-signal ASIC that consists
of 128 channels, each one having a charge sensitive amplifier with
continuous reset, configurable pole-zero cancellation, a CR-RC
shaper with variable shaping time, a comparator and a DAC to tune
the comparator threshold. For each channel an asynchronous ripple
counter and additional digital circuitry is available to count the
number of hits and to serialize the counter reading. The digital
circuitry uses differential current logic to minimize digital to
analogue crosstalk and substrate noise coupling. The shaping time,
the pole-zero cancellation and the TRIM-DAC is configured via an I2C
interface. In this talk the detector system, the ASIC architecture
and performance measurements will be presented.
Primary author
Dr
Michael Karagounis
(Universitaet Bonn)
