Transition-Edge Sensors for X-Ray Science ApplicationsPublic
This thesis forcuses on the development of the transition-edge sensor (TES) for various X-ray science applications, especially for synchrotron beamline experiments. The ultimate aim is to build a detector that has a higher energy resolution than semiconductor detectors, and a higher operation speed than crystal spectrometers. The possible applications include X-ray spectroscopy, Compton profile measurement and energy-dispersive X-ray diffraction. The latter two are discussed in detail, and we designed a prototype TES to meet the requirements of these applications. In order to better address the nonlinear signal response function of the TES and therefore improve the energy resolution of the TES, we studied the temperature and current dependence of the TES resistance. It is found that adding normal metal bars on the TES superconducting film will change not only the current flow pattern, but also the resistance dependence on temperature and current, at the low bias state. We also studied X-ray absorber materials, and found that bismuth is a good absorber material, and should be fabricated using electrodeposition methods so that the grain size is large enough that there is no energy loss during the photon energy down-conversion process, so that there is no undesired low-energy tail. In order to improve the operation speed, we adopted a frequency-division multiplexing scheme with microwave resonators and superconducting quantum interference devices (SQUIDs). This thesis has shown how to set up the experiment stage, and showed how to characterize the noise and signal response of the multiplexing electronics. The TESs have been characterized under this multiplexing readout scheme, and have demonstrated an energy resolution better than silicon detectors.