Soluzioni innovative di rivelatori a deriva di silicio per sorgenti di luce di terza e quarta generazione

L\u2019attivit\ue0 di ricerca qui presentata ha avuto come oggetto lo studio di soluzioni innovative per espandere le potenzialit\ue0 dei rivelatori basati sulla camera a deriva di silicio (SDD) destinati in particolare all\u2019uso sulle linee di luce presenti nelle macchine acceleratrici di terza e quarta generazione. Le camere a deriva sono strumenti oramai consolidati e comunemente usati negli esperimenti di fluorescenza a raggi X con ottime prestazioni per quanto riguarda la risoluzione energetica ma con alcune limitazioni che incidono in particolare sul tasso massimo dei conteggi rilevabili e gestibili dagli strumenti. In questo lavoro, dopo una breve introduzione al contesto e alle tecnologie attualmente disponibili per quanto riguarda i SDD, sono riportati e discussi alcuni nuovi approcci introdotti sia per aumentare l\u2019angolo solido coperto dai rivelatori sia per gestire alti tassi di conteggio, il tutto corredato dai risultati pi\uf9 significativi ottenuti dalle numerose prove sperimentali con prototipi appositamente sviluppati

First results of a novel Silicon Drift Detector array designed for low energy X-ray fluorescence spectroscopy

We developed a trapezoidal shaped matrix with 8 cells of Silicon Drift Detectors (SDD) featuring a very low leakage current (below 180 pA/cm2 at 20 \ub0C) and a shallow uniformly implanted p+ entrance window that enables sensitivity down to few hundreds of eV. The matrix consists of a completely depleted volume of silicon wafer subdivided into 4 square cells and 4 half-size triangular cells. The energy resolution of a single square cell, readout by the ultra-low noise SIRIO charge sensitive preamplifier, is 158 eV FWHM at 5.9 keV and 0 \ub0C. The total sensitive area of the matrix is 231 mm2 and the wafer thickness is 450\u3bcm. The detector was developed in the frame of the INFN R&D project ReDSoX in collaboration with FBK, Trento. Its trapezoidal shape was chosen in order to optimize the detection geometry for the experimental requirements of low energy X-ray fluorescence (LEXRF) spectroscopy, aiming at achieving a large detection angle. We plan to exploit the complete detector at the TwinMic spectromicroscopy beamline at the Elettra Synchrotron (Trieste, Italy). The complete system, composed of 4 matrices, increases the solid angle coverage of the isotropic photoemission hemisphere about 4 times over the present detector configuration. We report on the layout of the SDD matrix and of the experimental set-up, as well as the spectroscopic performance measured both in the laboratory and at the experimental beamline. \ua9 2015 Elsevier B.V

A new detector system for low energy X-ray fluorescence coupled with soft X-ray microscopy: First tests and characterization

The last decades have witnessed substantial efforts in the development of several detector technologies for X-ray fluorescence (XRF) applications. In spite of the increasing trend towards performing, cost-effective and reliable XRFsystems, detectors for soft X-ray spectroscopy still remain a challenge, requiring further study, engineering and customization in order to yield effective and efficient systems. In this paper we report on the development, first characterization and tests of a novel multielement detector system based on low leakage current silicon drift detectors (SDD) coupled to ultra low noise custom CMOS preamplifiers for synchrotron-based low energy XRF. This new system exhibits the potential for improving the count rate by at least an order of magnitude resulting in ten-fold shorter dwell time at an energy resolution similar to that of single element silicon drift detectors

Towards a multi-element silicon drift detector system for fluorescence spectroscopy in the soft X-ray regime

In spite of the constant technological improvements in the field of detector development, X-ray fluorescence (XRF) in the soft X-ray regime remains a challenge. The low intrinsic fluorescence yield for energies below 2 keV indeed renders the applicability of low-energy XRF still difficult. Here, we report on a new multi-element multi-tile detection system currently under development, designed to be integrated into a soft X-ray microscopy end station. The system will be installed at the TwinMic beamline of Elettra synchrotron (Trieste, Italy) in order to increase the detected count rate by up to an order of magnitude. The new architecture is very versatile and can be adapted to any XRF experimental setup. Even though the first results of the previous version of such a multi-element system were encouraging, several issues still needed to be addressed. The system described here represents a further step in the detector evolution. It is based on four trapezoidal-shaped monolithic silicon drift detector tiles (matrices) with six hexagonal elements each equipped with a custom ultra-low noise application-specific integrated circuit readout. The whole signal processing chain has been improved leading to an overall increase in performances, namely, in terms of energy resolution and acquisition rates. The design and development of this new detection system will be described, and recent results obtained at the TwinMic beamline at Elettra will be presented. Future perspectives and improvements will also be discussed