Parts | Days | Selection | Search | Updates | Downloads | Help
T: Fachverband Teilchenphysik
T 35: Semiconductor Detectors - Radiation Hardness, New Materials and Concepts
T 35.3: Talk
Tuesday, March 16, 2021, 16:30–16:45, Tj
Charge collection depth profile of pad diodes — •Mohammadtaghi Hajheidari1, Erika Garutti1, Joern Schwandt1, and Aliakbar Ebrahimi2 — 1Institut für Experimentalphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Deutschland — 2Paul Scherrer Institute, Villigen, Switzerland
The charge collection of two 150 µ m thick n+pp+ pad diodes has been scanned along the diode thickness using a 4.2 GeV electron beam at DESY II beam test facility. The electron beam enters from the sensor edge and its position along the edge was reconstructed by three planes of a EUDET-type telescope.
The diodes have an area of 25 mm2 and a p-doping concentration of 4×1012 cm−3. The measurements were performed at − 20 ∘C for bias voltages up to Vbias = 800 V. One diode was not irradiated while the other one was irradiated with 23 MeV protons to a 1 MeV neutron equivalent fluence of Φeq = 2×1015 cm−2. For the non-irradiated diode, the charge profile is uniform as a function of the depth. For the irradiated diode, the charge profile is non-uniform and it changes with the applied bias voltage.
In this presentation, the online alignment and the measurement procedures, as well as preliminary results are presented. The results can be used to obtain an electric field depth profile, needed in simulations of charge collection in diodes and segmented silicon sensors.