Design and development of electronics and the control software for the silicon tracker of LHCb

Resumen

The development of this thesis is related to the Silicon Tracker (ST) detector of the LHCb experiment at CERN. The ST consists of two sub-detectors, the Inner Tracker (IT) and the Tracker Turicensis (TT). This thesis covers the following essential aspects of the ST: ¿ Design and Development of the control electronics and software for the ST detector. ¿ Design and Development of the High Voltage (HV) and Low Voltage (LV) systems of the ST. ¿ Design of the production facility for the construction of 400 silicon modules of Inner Tracker (IT) detector and commissioning of the ST detector in the experimental area. The control system performs the tasks of control and supervision of the whole detector electronics as well as monitoring of environmental parameters such as temperatures and humidity. The system consists of a software and a hardware side: ¿ The hardware. Both the acquisition and digitization electronics need different signals to control and operate properly within the LHCb specifications. Among these signals are the "slow control" and the "fast control" signals. The "slow" signaling are basically the commands needed to configure and monitor each of the acquisition devices, whereas the "fast control" stands for the all the signals used for the synchronization of the entire LHCb (40 MHz clock, trigger at 1MHz, front-end resets and calibration). In addition, temperature and humidity monitoring is needed in order to assess the safe working of the detector. All these functionalities are integrated in the "Control Board", whose development is one of the cornerstones of this thesis. This board is exposed to rather high ionizing radiation levels (60 krad), which means it has been designed for radiation tolerance. In total, 60 boards have been produced for the ST. ¿ The software. The Control System for the ST is based on the PVSS SCADA, which is a common tool used by the four experiments at CERN. This SCADA is a development environment designed to control and acquire data from different devices, having the advantage that permits deploying distributed control systems running in different platforms. This feature is essential to control systems of big magnitude such as the LHCb experiment, where 1 million channels are readout at 40 MHz. This software integrates the HV, LV, the control and the data acquisition electronics, the temperature and humidity supervision, as well as the cooling system into one highly hierarchical and distributed entity able to control the entire detector as a one. The design and deployment of the high voltage and low voltage distribution systems is described in detail: definition of requirements, survey of equipment and components available in the market that withstand the experiment needs (radiation and high magnetic field tolerance, SCADA interface, power budget...) and proposal of the final solution in terms of equipment, cabling, distribution and system control. Regarding to the detector construction, the main issues are the development of the system to perform temperature cycling tests of the IT silicon modules built at CERN. Custom electronics was developed and integrated into a system to perform burn-in tests of the IT modules with temperature and humidity monitoring. Concerning the commissioning of the detector in the experimental area, fundamental aspects, problems found and solutions adopted during the detector installation are also reported in this writing.