Speaker
Description
The development of vertex and tracking detectors for future lepton colliders faces various challenges regarding time and position resolution while maintaining a low material budget and the capability to process high particle rates. In this context, one approach to improve the spatial resolution is to utilise the effect of charge sharing. Here, the charge carriers generated in the sensor volume are shared between neighbouring readout electrodes, thus forming a cluster. The cluster size indicates the degree of charge sharing between adjacent readout electrodes while the ratio of the signal amplitudes associated with the cluster gives information about the hit position of the traversing particle.
By applying a magnetic field and exploiting the Lorentz drift of the generated charge carriers in the sensor volume, an increase in charge sharing can be observed. The same effect can be achieved geometrically by rotating the sensor. However, neither approach is suitable for vertex detectors, since the effect is not sufficient in the case of thin sensors.
The enhanced lateral drift (ELAD) sensor prototype addresses the aforementioned requirements by featuring a multiple-layer design including buried doping implants. The deep implants generate an additional lateral electric field inside the sensor bulk, resulting in increased charge sharing which is indicated by an increased amount of clusters of size two. Through simulations, the sensor design was optimised to allow for position-dependent charge sharing close to the theoretical optimum, which results in an improved impact position interpolation.
This talk presents first results of the characterisation of an ELAD sensor prototype including preliminary results of test beam studies carried out at the DESY II test beam facility. These studies showed the aforementioned increased amount of clusters of size two, thus indicating an increase in charge sharing compared to strip sensors without ELAD implants.