Scintillation Light Detection and Application of Silicon Photomultipliers in Imaging Calorimetry and Positron Emission Tomography

Diese Arbeit befasst sich mit den schwachen Lichtsignalen von organischen und anorganischen Szintillatoren und deren Nachweis mit Silizium Photomultipliern (SiPM). In diesem Zusammenhang werden zwei Anwendungsgebiete untersucht: Hadronkalorimeter und das bildgebende Verfahren der Positronen-Emissions-Tomographie. Das Ergebnis einer Messung des Birksschen Koeffizienten kB wird vorgestellt für die Plastikszintillatorkacheln des analogen hadronischen Kalorimeterprototyps der CALICE Kollaboration. Der ermittelte kB-Wert ist signifikant größer als der bisher in Geant4-Simulationsstudien benutzte Wert. Eine neue Simulationsmethode wurde entwickelt, mit deren Hilfe eine verbesserte Beschreibung des Ionisations-Quenching-Effekts möglich ist. Der Einfluss auf das simulierte Kalorimetersignal wird anhand einer Teilchenschauer-Simulationsstudie verdeutlicht. Eine Testumgebung wurde entwickelt um eine vollständige SiPM Charakterisierung zu ermöglichen und verschiedene SiPM Bauarten zu vergleichen. Das Messspektrum umfasst die Bestimmung der Photon-Detektions-Effizienz unter Berücksichtigung der Beiträge des optischen Übersprechens und der auftretenden Nachpulse. Zusätzlich wurde das räumliche Ansprechverhalten einzelner Pixel gemessen. Die gewonnenen Erkenntnisse zu den unterschiedlichen Sensortypen und die daraus abgeleitete Qualifikation für verschiedene Anwendungsgebiete werden diskutiert. Um die Eignung von SiPMs für die Positronen-Emissions-Tomographie zu untersuchen, wurde ein Detektorprototyp im kleinen Maßstab entwickelt. Erste Charakterisierungsstudien des Systems werden vorgestellt

Characterisation Studies of Silicon Photomultipliers

This paper describes an experimental setup that has been developed to measure and characterise properties of Silicon Photomultipliers (SiPM). The measured SiPM properties are of general interest for a multitude of potential applications and comprise the Photon Detection Efficiency (PDE), the voltage dependent cross-talk and the after-pulse probabilities. With the described setup the absolute PDE can be determined as a function of wavelength covering a spectral range from 350 to 1000nm. In addition, a method is presented which allows to study the pixel uniformity in terms of the spatial variations of sensitivity and gain. The results from various commercially available SiPMs - three HAMAMATSU MPPCs and one SensL SPM - are presented and compared.Comment: 11 pages, 21 figures, submitted to Nuclear Instruments and Methods in Physics Research Section

Scintillation Light Detection and Application of Silicon Photomultipliers in Imaging Calorimetry and Positron Emission Tomography

This thesis deals with the weak light signals created in organic and inorganic scintillators, and their detection with silicon photomultipliers (SiPM). In this context, two fields of application are studied: hadron calorimetry, and the medical imaging technique of positron emission tomography. The result of a measurement of Birks’ coefficient kB is presented for the plastic scintillator tiles used in the analogue hadronic calorimeter prototype of the CALICE collaboration. The extracted kB is significantly larger compared to the default value used in previous Geant4 simulation studies. A new simulation method was developed which enables an improved description of the ionisation quenching effect. The impact on the simulated calorimeter response is demonstrated by means of a particle shower simulation study. A test environment was developed in order to pursue a complete SiPM characterisation, thus enabling a comparison of different SiPM types. The range of measurements covers the determination of the cross-talk and after-pulse corrected photon detection efficiency, and measurements of the spatial uniformity of single pixels. The characteristics of several different SiPM types and the derived qualification for different fields of application are discussed. In order to investigate the utility of SiPMs for the positron emission tomography application, a small-scale detector prototype was developed. First characterisation studies on the system are presented

ILC Reference Design Report Volume 1 - Executive Summary

The International Linear Collider (ILC) is a 200-500 GeV center-of-mass high-luminosity linear electron-positron collider, based on 1.3 GHz superconducting radio-frequency (SCRF) accelerating cavities. The ILC has a total footprint of about 31 km and is designed for a peak luminosity of 2x10^34 cm^-2s^-1. This report is the Executive Summary (Volume I) of the four volume Reference Design Report. It gives an overview of the physics at the ILC, the accelerator design and value estimate, the detector concepts, and the next steps towards project realization.The International Linear Collider (ILC) is a 200-500 GeV center-of-mass high-luminosity linear electron-positron collider, based on 1.3 GHz superconducting radio-frequency (SCRF) accelerating cavities. The ILC has a total footprint of about 31 km and is designed for a peak luminosity of 2x10^34 cm^-2s^-1. This report is the Executive Summary (Volume I) of the four volume Reference Design Report. It gives an overview of the physics at the ILC, the accelerator design and value estimate, the detector concepts, and the next steps towards project realization