R&D on Microstrip IR Transparent Silicon Sensors

The next generation of tracking systems, as the one envisaged for the International Linear Collider (ILC) will demand track momentum resolutions one order of magnitude better than current state-of-the-art trackers. Mechanical stabilities coping with the precision of such measurements should either be provided by the construction of the supporting structure (currently out of the technological reach) or monitored using an alignment system. Based on the successful experience of AMS and CMS tracker systems, we propose to use infrared laser beams traversing consecutive layers of silicon detectors to align them with respect to the beams. Laser beam \pseudo-tracks" work like innite momentum particle tracks. Yet we have slightly altered the thicknesses of the dieren t material layers and the pitch/strip-width ratio of the sensors to obtain maximum transmittance to the IR beam, without modifying its performance as a tracking device. Replacement of the Aluminum electrodes by semitransparent oxides like ITO have also been considered. Transmittances close to 80% for IR beams can thus be obtained.