Challenges for picosecond time resolution at high influences with 3D Silicon sensors

• Vagelis Gkougkousis (University of Zurich)

Room: SUPA Room 255 The proven radiation hardness of silicon 3D devices up to fluences of 1x10^17 n_eq/cm^2 makes them an excellent choice for next generation trackers, providing <10mum position resolution at a high multiplicity environment. The anticipated pile-up increase at HL-LHC conditions and beyond, requires the addition of < 50 ps per hit timing information to successfully resolve displaced and primary vertices. In this study, the timing performance, uniformity, and efficiency of neutron and proton irradiated single pixel 3D devices is investigated. Three different geometrical implementations are evaluated for fluences up to 1x10^17 n_eq/cm^2 at 120 GeV SPS pion beams. The question of electronic bandwidth is also addressed, with respect to achievable time resolution, efficiency and collected charge. In such a tri-dimensional phase-space, an appropriate operating point is selected depending on the application requirements. A MIMOSA26 type telescope is used to provide detailed tracking information with a ~5mum position resolution. Productions with single- and double-sided processes, yielding active thickness of 130 and 230 mum respectively, are studied, with pixel sizes that vary from 55 x 55 mum^2 to 25 x 100mum^2. A comparison of field uniformity with respect to electrode geometry is presented, as well as a time resolution study for incidence angles up to 12 degrees.