Test results of monolithic active pixel sensors for charged particle tracking

A new generation of semi-conducting pixel sensors for detecting minimum ionising particles (m.i.p.) was designed and first prototypes of Monolithic Active Pixel Sensors (MAPS), called MIMOSA, were fabricated in a standard CMOS technology. The performances of the first prototypes were evaluated with high energy π- beams and with an X-ray source in strong magnetic fields. The beam test results demonstrate that the sensors detect m.i.p.s with very high efficiency and signal-to-noise ratio and provide excellent spatial resolution. The influence of strong magnetic fields is observed to be modest