Speaker
Manfred Valentan
(Austrian Academy of Sciences (AT))
Description
The innermost Pixel Detector (PXD) of the Belle II experiment makes use of the DEPFET (Depleted P-channel Field Effect Transistor) technology to provide the accurate position measurements that are needed for the reconstruction of B meson decay vertices. It has to work in very challenging conditions: The instantaneous luminosity of 8x10^35 cm^2s^-1 expected at SuperKEKB causes a high event rate and a large background, the resulting sensor occupancy is furthermore increased by the PXD's close proximity to the interaction point.
A general introduction of the PXD can be found in talk 396 "Inner tracking devices at the Belle II experiment". As a complement, this poster presents the strategies of how to deal with the aforementioned challenging conditions in terms of sensor layout and electronic readout. Highlights include the four-fold rolling shutter readout (making readout four times as fast), segmenting the sensor to allow different operating voltages (to deal with inhomogeneous irradiation), zero-suppressed readout focussed on small "Regions of Interest" (to suppress background hits), and a fast electronic shutter, the so-called "Gated Mode" (to make the sensor blind during short periods of increased background particle flow).
additional information
Submitted on behalf of the Belle II collaboration.
Author
Manfred Valentan
(Austrian Academy of Sciences (AT))
