|BANIAHMAD ATA||Cycle: XXXIII |
Tutor: GERACI ANGELO
Advisor: FIORINI CARLO ETTORE Major Research topic
:Development and Characterization of Silicon Drift Detector arrays and integrated readout electronics for X-ray detection applicationsAbstract:
The aim of this doctoral activity has been the modelling, design and characterization of X-ray detection systems based on silicon drift detectors (SDDs) and a low-noise integrated multichannel readout front-end for solid-state detectors signal processing in the field of nuclear electronics.
When dealing with X-ray spectroscopy and nuclear physics experiments, the main focus is undoubtedly optimizing the energy resolution of the overall detection system. Therefore, for a given application, provided the incident photons energy and rate, design efforts are typically oriented to minimize the noise introduced by the acquisition chain, made of both detector and readout electronics. Thanks to the technological advances the microelectronics industry has encountered in the last fifteen years, readout frontends are often implemented as multichannel application specific integrated circuits (ASICs) so as to cope with the increasingly high number of units in the detection modules.
My PhD research activity is concluded on three main subjects: First part of my research activity is dedicated to Siddharta experiment. This experiment is an upgrade of the first one held in 2009 in Frascati (Rome) and both are meant to provide a deeper knowledge of the strong-interaction inside atoms, which is not completely defined due to the absence of experimental data. To gain new information, the experiment needs to measure as accurate as possible the shift and the amplitude of the K-alpha emission line of the Kaonic Hydrogen, an exotic atom. The first installation of the experiment provided useful data since it was the first-ever measurement of the Kaonic Deuterium X-rays, but still had some limitations in resolution mostly due to noise, so it was necessary an upgrade which will be running in 2020. Both the detectors and readout electronics have been improved to match the noise requirements, so they have to be fully characterized before using them in final experiment. There are two main topics covered in this research activity during my PhD. First part is dedicated to installation of Silicon Drift detectors (SDD), development of the acquisition chain, and post-processing of the acquired data to analyse the functionality of the detectors and readout electronics. The second part is dedicated to characterization of SDDs and dealing with unexpected behaviours encountered during the characterization procedure. Beside that some development in the low-noise integrated multichannel readout front-end electronics has been done. Second part of my research activity is dedicated to HTRS ASIC. HTRS is a front-end ASIC for the readout of multi-elements Silicon Drift Detectors specifically designed for high count-rate X-ray spectroscopy applications. In particular, the focus is on the maximization of the event throughput and, at the same time, keeping a high energy resolution. HTRS is going to be used in eXTP (enhanced X-ray Timing and Polarimetry) mission, a scientific space mission designed to study the state of matter under extreme conditions of density, gravity and magnetism. Primary goals are the determination of the equation of state of matter at supra-nuclear density, the measurement of QED effects in the radiation emerging from highly magnetized stars, and the study of matter dynamics in the strong-field regime of gravity. The eXTP mission will revolutionize these areas of fundamental research by high precision X-ray measurements of NSs across the magnetic field scale and BHs across the mass scale. In addition to investigating fundamental physics, eXTP will be a very powerful observatory for astrophysics, which will provide observations of unprecedented quality on a variety of galactic and extragalactic objects. Covering and solving the issues MPE institute faced during the HTRS ASIC installation and redesign of the ASIC carrier board and test setup have been done during my research activity. Third part of my research activity is dedicated to the development of 128 channel ASIC for the readout of silicon microstrip detectors with high counting rate efficiency and high energy resolution for X-ray diffractometry. This ASIC finds wider applications with other detector solutions as well. ASIC Study and possible modifications to solve the issues identified in wafer level characterization of the chip has been done.