Development and applications of transition-edge sensors

Abstract

This thesis focuses on the theory, development and applications of Transition- Edge Sensor (TES) arrays. The main results are the design and development of a fabrication process for a 256 pixel X-ray TES detector with a novel geometry and the development of a measurement setup for TES detectors used in elemental analysis with Particle Induced X-ray Emission (PIXE) measurements. In the early stages of this thesis we fabricated a small scale 32 pixel TES array, but for an actual application purposes the pixel count and the consistency of the fabrication needs to be higher. The cleanroom facilities in the Nanoscience Center are well suited for basic research but they are not suitable for a wafer scale processing. To make the fabrication of a large scale TES array possible we collaborated with VTT (Technical Research Centre of Finland) and used their Micronova clean room facilities for the fabrication of the detectors. We've shown a setup consisting of 12 pixels being used in a PIXE measurement with the best pixel having a remarkable 3.06 eV energy resolution at 5.9 keV. This kind of resolution has not been reported before for a wide band energy dispersive detector used in a PIXE system. The thesis will also show experiments done with an updated measurement system capable of analyzing the elemental contents of thin lm samples with 60 pixels. Also the energy e ciency of the setup is reported