Performance Studies on 2S Module Prototypes for the Phase-2 Upgrade of the CMS Outer Tracker

In the course of the Phase-2 Upgrade of CMS the Outer Tracker of the experiment will be replaced.

The thesis investigates the performance of 2S Module prototypes for the future Outer Tracker. 

The first part focuses on the comparison of the performance of two different sensor thicknesses for the application in the future tracker. Different aspects has been investigated:

• the influence of operation parameters (temperature, sensor bias voltage and leakage current) on the module's noise,
• the impact of sensor defects on the module performance,
• the calibration of the comparator threshold DAC value (Vcth) of readout chip (CBC) into a charge signal equivalent,
• the efficiency and single hit resolution of the sensors in a beam test.

Based on this measurements the FZ290 sensors have been chosen for the future Outer Tracker.

The second part investigated the high rate stability of the 2S module readout chain on prototypes using the KARATE setup at KIT. The stability of the readout chain for expected data rates at pileup 200 and 750kHz trigger rate has been shown by using injection pattern based on CMSSW simulations. The limits of the readout chain regarding trigger rate and pileup has been determined. Furthermore, an algorithm for the trigger throttling system has been proposed to prevent the appearance of readout buffer overflows of the CBC at high trigger rates.