Parts | Days | Selection | Search | Downloads | Help
HK: Fachverband Hadronen und Kerne
HK 84: Accelerators and Instrumentation I
HK 84.4: Talk
Friday, March 20, 2009, 11:45–12:00, H-ZO 80
Development of radiation hard silicon sensors for the CBM Silicon Tracking System using Simulation approach — •Sudeep Chatterji — GSI, Darmstadt
The very intense radiation environment of the planned Compressed Baryonic Matter (CBM) experiment at the international research center FAIR makes radiation hardness the most important issue for the Silicon Tracking System (STS). STS will consist of eight stations of double sided strip detectors at a distance between 25 cm to 100 cm downstream of the target. It is expected that the total integrated fluence will reach 1 × 1015 cm−2 1 MeV neutrons equivalent which is more than expected at LHC at CERN. The major macroscopic effect of radiation damage in determining the viability of long-term operation of silicon sensors is the change in the effective charge carrier concentration (Neff), leading to type inversion. For the safe operation over full CBM life time, detectors are required to sustain very high voltage operation, well exceeding the bias voltage needed to fully deplete the heavily irradiated sensors. Thus, the main effort in the development of silicon sensors is concentrated on a design that avoids p-n junction breakdown at operational biases.
Simulations are carried out to study the effect of change in Neff, as well as crucial geometrical parameters, on the breakdown performance using the PISCES code. Process simulation has also been performed using SUPREM-4 for studying the annealing behaviour of implanted dopant.
* Supported by EU-FP6 HadronPhysics