@phdthesis{Novgorodova2013, author = {Novgorodova, Olga}, title = {Characterisation and application of radiation hard sensors for LHC and ILC}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-29516}, school = {BTU Cottbus - Senftenberg}, year = {2013}, abstract = {The Large Hadron Collider (LHC) currently in operation intends to explore particle physics on the TeV scale. The International Linear Collider (ILC) and the Compact Linear Collider (CLIC) are being designed to measure the properties of particles possibly discovered at the LHC with high precision. Very forward detector systems at these machines are needed for the precise measurement of the luminosity and to approach full polar angle coverage. In the current detector concepts for linear collider detectors two electromagnetic calorimeters, Beam Calorimeter (BeamCal) and Luminosity Calorimeter (LumiCal), are foreseen. Both calorimeters are designed as sandwich calorimeters with tungsten absorber layers instrumented with finely segmented sensors. Due to a large amount of beamstrahlung remnants hitting BeamCal at the innermost radii, the sensors must withstand up to 1 MGy radiation dose per year. In this thesis two types of sensor materials were investigated: single crystal chemical vapour deposition diamonds (scCVDD) and gallium arsenide doped by chromium (GaAs:Cr). The very forward calorimeters ensure coverage for high energy electrons, positrons and photons down to very low polar angles. Within this thesis, simulation studies are presented for different beam parameters of the ILC. A new sensor segmentation was proposed to achieve better reconstruction efficiency of single high-energy electrons, positrons and photons on top of the beamstrahlung background. Only for a few years ago polycrystalline diamond sensors have been used for beam diagnostics in high-energy physics experiments. The Compact Muon Solenoid experiment, CMS, at the LHC is instrumented with several detectors for the Beam Conditions and Radiation Monitoring. The Fast Beam Conditions Monitor (BCM1F) is part of these systems. Here for the first time single crystal diamond sensors have been used. Eight detectors, comprising each a single crystal sensor and front-end electronics, are positioned around the beam pipe on both sides of the interaction region. They monitor the beam halo to protect the inner CMS detectors from adverse beam conditions and ensure high quality data for CMS. In this thesis, BCM1F data is evaluated for intrinsic time resolution and performance under harsh radiation conditions. Furthermore, it is investigated if it can be used for a bunch by bunch on-line luminosity measurement. The second type of sensor, made of GaAs:Cr, was produced in Tomsk State University and tested as a candidate for the BeamCal for future ILC and CLIC detectors. Several GaAs:Cr sensors were characterized in the laboratory for leakage current and capacitances and used for test beam investigations. Two sensors were assembled with a fan-out, front-end and ADC ASICs to build a fully functional prototype of a sensor plane. Several test beam campaigns were done to measure the performance of the system.}, subject = {LHC; Strahl{\"u}berwachung; Sensor; FCAL; CMS; LHC; ILC; BeamCal; FCAL; CMS; LHC; ILC; BeamCal}, language = {en} } @phdthesis{Bergholz2015, author = {Bergholz, Matthias}, title = {Vergleich relevanter Parameter von Multipixelsensoren f{\"u}r Spurdetektoren nach Bestrahlung mit hohen Proton- und Neutronfl{\"u}ssen}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-36359}, school = {BTU Cottbus - Senftenberg}, year = {2015}, abstract = {Um eine h{\"o}here Sensitivit{\"a}t f{\"u}r seltene Physikereignisse zu erzielen, wird die Luminosit{\"a}t am LHC in der dritten Upgrade-Phase um den Faktor f{\"u}nf gesteigert. Die damit verbundene Steigerung der Wechselwirkungsrate bedingt f{\"u}r den CMS-Spurdetektor strahlungsh{\"a}rtere Sensoren. Um das geeignetste Material zu finden, wurde die HPK-Kampagne gestartet. Ziel der Kampagne ist es, die auf dem Markt verf{\"u}gbaren Siliziumsubstrate und Prozesstechnologien auf ihre Eignung zu {\"u}berpr{\"u}fen. In der vorliegenden Arbeit wurden aus der HPK-Kampagne die sogenannten MPix-Sensoren untersucht. Daf{\"u}r wurde zun{\"a}chst eine Probestation in Betrieb genommen und die Steuerungssoftware programmiert. Zus{\"a}tzlich wurden neuartige Auswertungsmethoden entwickelt und eine Datenbank eingerichtet. Zur Untersuchung der {\"A}nderung der Sensoreigenschaften durch Bestrahlung wurden die MPix-Sensoren zun{\"a}chst vor der Bestrahlung charakterisiert und die Ergebnisse anschließend mit den Ergebnissen nach Bestrahlung verglichen. Der Untersuchungsfokus lag auf dem Einfluss des Sensorsubstrats, der Produktionstechnologie und der Bias-Strukturen und der Strahlenh{\"a}rte. Durch Bestrahlung degenerierten die Sensortypen unterschiedlich stark. Der Anstieg des Stromes durch Bestrahlung ist kleiner f{\"u}r Sensoren aus Magnetic-Czochralski-Silizium verglichen mit Sensoren aus Float-Zone-Silizium. F{\"u}r Sensoren aus Float-Zone-Silizium ist der Stromanstieg schw{\"a}cher f{\"u}r 200 µm dicke Sensoren verglichen mit 320 µm dicken Sensoren. Bias-Strukturen aus Polysilizium und Punch-Through-Struktur werden durch die Bestrahlung gesch{\"a}digt. Bei Strukturen aus Polysilizium steigt der Widerstand durch Bestrahlung um etwa 50\% und bei der Punch-Through-Struktur steigt die Punch-Through-Spannung um den Faktor zwei.}, subject = {Multipixelsensoren; Strahlenh{\"a}rte; CMS; HPK-Kampagne; Spurdetektor; Compact Muon Solenoid; HPK campaign; Multi-pixel sensors; Tracker; Radiation hardness; CMS-Detektor; Sensor; Spurdetektor; Strahlenresistenz}, language = {de} }