Разработка системы хранения, контроля и визуализации информации Трекового детектора переходного излучения в эксперименте ATLAS (ЦЕРН)

The thesis is devoted to research, analysis, development and implementation of software for the detector monitoring, for database tools and also for recorded data quality control of the ATLAS Transition Radiation Tracker (TRT). The TRT is the outermost of the three sub-systems of the ATLAS inner tracking detector at the Large Hadron Collider (LHC) at CERN and is one of the important tools to reconstruct tracks of charged particles and to identify the particle species. TRT contains more than 350,000 channels of information and reading more than 22600 units of electronics. The TRT consists of thin proportional chambers either in the form of straws embedded in fibers or with foils and straws in separate layers. Straws are providing the registration the time and amplitude parameters of a signal. Readout electronics set two independent thresholds to cut the noises and separate the transition radiation events. Different effects and conditions as synchronization of a time parameters of the detector and LHC are influence on measurements of the time for signal to pass throw the channels and time for particle to fly throw the straw. Monitoring the system with such number of channels and nodes is a challenge even with the modern computer technology. Under these conditions dramatically increasing the demands on the level of software which actually cover all the functions of monitoring and control. The uniqueness of the experiment hardware and more importantly its size, requires a completely new approach to the development and implementation of software systems. To operate with an unprecedented amount of experimental data and the large number of information channels of TRT in the thesis were developed: -methods and algorithms for storing large amounts of configuration data; -methods and algorithms for data access to provide a single universal mechanism for working with detector databases; -methods and algorithms for graphical representation of data detector for monitoring the state of the systems and data quality control. Also one of the solved problems is the maximum integration in the development of new components in heterogeneous software infrastructure of experiment. Regular users and most of experts don’t interact with experimental apparatus and front-end electronics directly. Instead of this they interact with Data Acquisition System (DAQ) and Detector Control System (DCS) via corresponding databases. Within this thesis the work was done on TRT DAQ CORAL Configuration database projects. The TRT DAQ CORAL Configuration database is used to store readout electronics and trigger settings that – in the continuous operation of the ATLAS detector - change fairly often, like fine delays and thresholds. These quantities and settings need to be fine-tuned and calibrated in regular intervals to keep the high performance of the particle detector. The same database is used for both standalone operation of the TRT and combined running together with all other ATLAS subdetectors. The database archives use configurations, which are also used in the track reconstruction and provide the settings which are used for each data taking run the TRT participates in. Also was made significant contribution in developing the tools for accessing this database and he implemented the methods to interact with the Detector Control System. Most of DCS services are implemented using PVSS system under which two databases are deployed: PVSS archive and Configuration DB. Software methods and algorithms to access these databases were developed. Implemented software was used in special tool for low voltages and currents control. Another project described in the thesis is monitoring tool called TRTViewer. The TRTViewer is a special and dedicated tool that combines the capabilities of an event display with the detector performance monitoring. Also TRTViewer can be used as histogram and operation parameters presenter, working with different sources of input data: raw data files; DAQ; online monitoring histograms; offline analysis histograms; TRT DAQ Configuration database. Software tool based on ROOT libraries for dedicated analysis of the ATLAS TRT performance at different hardware levels. The TRTViewer extracts the TRT information from the raw data and provides both a real-time event display and an analysis package that does track reconstruction, efficiency calculations, noise occupancy maps, and error monitoring. The corresponding histograms can also be viewed via standard ROOT browser. It gives a possibility for very fast and clean determination of general TRT electronics functionality and localization of abnormalities, if any. This tool can also provide an interface to the configurations database, and has the ability to re-calibrate the detector thresholds and timing based on information extracted from the monitoring process. During the commissioning of the detector the TRTViewer was one of the main tools which ensured that the highly sophisticated measurement devise could be calibrated and understood. Also today and in the future the TRTViewer will be the essential tool to keep up the excellent performance of the detector. TRTViewer is included as one of obligatory tools to be used during TRT run shifts. Author of the thesis worked on the important modules application which are responsible for GUI, graphics, database access and Informational Service access. All the tools and software which were designed, implemented, tested and commissioned are fully integrated and are most important tools for the successful operation of the ATLAS Transition Radiation Tracker.