Characterisation of Glasgow/CNM Double-Sided 3D Sensors.

3D detectors are proposed as an alternative to planar silicon technology to withstand the high radiation environments in planned future high energy physics experiments. Here we review the characterization of double-sided 3D detectors designed and built at CNM and the University of Glasgow. A non-irradiated sensor is characterized in a pion test-beamutilizing the Timepix telescope. The charge collection and detection efficiency across the unit pixel are shown. Area of inefficiency can be found at the columnar electrodes at perpendicular angles of beam incidence while the pixels are shown to be fully efficient at angles greater than ten degrees. A reduction in charge sharing compared to the planar technology is also demonstrated. Charge collection studies on irradiated devices with a Sr-90 source show higher charge collection efficiency for 3D over planar sensors at significantly lower applied bias. The sub-pixel response is probed by a micro-focused laser beam demonstrating areas of charge multiplication at high bias voltages