Instruments of RT-2 Experiment onboard CORONAS-PHOTON and their test and evaluation II: RT-2/CZT payload

Cadmium Zinc Telluride (CZT) detectors are high sensitivity and high resolution devices for hard X-ray imaging and spectroscopic studies. The new series of CZT detector modules (OMS40G256) manufactured by Orbotech Medical Solutions (OMS), Israel, are used in the RT-2/CZT payload onboard the CORONAS-PHOTON satellite. The CZT detectors, sensitive in the energy range of 20 keV to 150 keV, are used to image solar flares in hard X-rays. Since these modules are essentially manufactured for commercial applications, we have carried out a series of comprehensive tests on these modules so that they can be confidently used in space-borne systems. These tests lead us to select the best three pieces of the 'Gold' modules for the RT-2/CZT payload. This paper presents the characterization of CZT modules and the criteria followed for selecting the ones for the RT-2/CZT payload. The RT-2/CZT payload carries, along with three CZT modules, a high spatial resolution CMOS detector for high resolution imaging of transient X-ray events. Therefore, we discuss the characterization of the CMOS detector as well.Comment: 26 pages, 19 figures, Accepted for publication in Experimental Astronomy (in press

Advances on CMOS image sensors

This paper offers an introduction to the technological advances of image sensors designed using complementary metal–oxide–semiconductor (CMOS) processes along the last decades. We review some of those technological advances and examine potential disruptive growth directions for CMOS image sensors and proposed ways to achieve them. Those advances include breakthroughs on image quality such as resolution, capture speed, light sensitivity and color detection and advances on the computational imaging. The current trend is to push the innovation efforts even further as the market requires higher resolution, higher speed, lower power consumption and, mainly, lower cost sensors. Although CMOS image sensors are currently used in several different applications from consumer to defense to medical diagnosis, product differentiation is becoming both a requirement and a difficult goal for any image sensor manufacturer. The unique properties of CMOS process allows the integration of several signal processing techniques and are driving the impressive advancement of the computational imaging. With this paper, we offer a very comprehensive review of methods, techniques, designs and fabrication of CMOS image sensors that have impacted or might will impact the images sensor applications and markets

A Radiation Imaging Detector Made by Postprocessing a Standard CMOS Chip

An unpackaged microchip is used as the sensing element in a miniaturized gaseous proportional chamber. Thisletter reports on the fabrication and performance of a complete radiation imaging detector based on this principle. Our fabrication schemes are based on wafer-scale and chip-scale postprocessing.\ud Compared to hybrid-assembled gaseous detectors, our microsystem shows superior alignment precision and energy resolution, and offers the capability to unambiguously reconstruct 3-D radiation tracks on the spot.\u

EndoTOFPET-US a Novel Multimodal Tool for Endoscopy and Positron Emission Tomography

The EndoTOFPET-US project aims to jointly exploit Time-Of-Flight Positron Emission Tomography (TOFPET) and ultrasound endoscopy with a multi-modal instrument for the development of new biomarkers for pancreas and prostate oncology. The paper outlines the functionality of the proposed instrument and the challenges for its realization. The high level of miniaturization and integration poses strong demands to the fields of scintillating crystallography, ultra-fast photon detection, highly integrated electronics and system integration. Solutions are presented to obtain a coincidence time resolution better than 200 ps and a spatial resolution of ~1 mm with an asymmetric TOFPET detector. A tracking system with better than 1 mm spatial resolution precision enables the online alignment of the system. The detector design, the production and test status of the single detecto

Development of an X-ray detection system based on polymer-based scintillator composites

Dissertação de mestrado em Engenharia Eletrónica Industrial e de ComputadoresNowadays, radiation processing techniques are used in many fields and are undergoing fast developments. The demand for improving spatial resolution and to obtain more clear and accurate images, while reducing the radiation doses, have led to the replacement of the traditional techniques based on X-ray films processing by digital processing techniques, that combine high efficiency electronic sensors with computing algorithms. However, these current techniques and radiation detection methods face severe limitations and high costs when large areas or flexible applications are involved. In this work an X-ray detection system was developed, with the aim of presenting an innovative solution, efficient, flexible, and capable of being produced in a large area and at a low cost. To achieve these objectives, a Styrene-Ethylene/Butadiene-Styrene (SEBS) polymer films were prepared, containing scintillator nanoparticles, Gd2O3:Eu3+, that are responsible for converting X-rays into visible light. These materials present unique characteristics like flexibility, stretchability and easy and low cost production. It was also developed a compact electronic circuit responsible for acquiring and processing the visible light produced by the scintillator material. This circuit is based on a photodetector matrix and auxiliary components that have to obtain visible light values, multiplex the matrix sensors and communicate the results to a microcontroller. Thereafter, a firmware to the microcontroller was implemented to control the whole system, from sensors acquisition to sending the data through serial communication to a user interface. The results are displayed and presented to the user in a clear and organized way, allowing the user to make an easy and direct analysis. Finally, the system was subject to tests according to a previously defined experimental methodology. In these experiments, the system revealed a fluid, solid and clean performance with room for optimization, improvements and adaptation to new and innovative applications.Actualmente, as técnicas de processamento de radiação são usadas em muitas áreas de investigação e aplicação, ao mesmo tempo que sofrem uma constante e rápida evolução. A necessidade de melhorar a resolução e obter imagens mais claras e precisas, ao mesmo tempo que é reduzida a quantidade de radiação, levaram a que as técnicas tradicionais baseadas no processamento de películas radiográficas fossem sendo substituídas por técnicas de processamento digital, que aliam sensores electrónicos de alta eficiência com programação algorítmica. No entanto, estas técnicas e métodos de detecção de radiação actuais enfrentam duras limitações e elevados custos quando é pretendida a produção de grandes áreas de detecção ou a integração em aplicações flexíveis. Nesta dissertação é desenvolvido um sistema de detecção de raio-X com o objectivo de apresentar uma solução inovadora, que seja eficiente, flexível e capaz de ser produzida em grandes áreas e a baixo custo. Para cumprir estes objectivos, foi preparada uma matriz polimérica de StyreneEthylene/Butadiene-Styrene (SEBS) contendo concentrações de nanopartículas cintiladoras, Gd2O3:Eu 3+, responsáveis por converter os raios-X em luz visível. Este material cintilador apresenta características ímpares, como flexibilidade, extensibilidade, baixo custo e fácil produção e replicação. Foi também desenvolvido um circuito electrónico de reduzidas dimensões, responsável por adquirir e processar a luz visível produzida pelo cintilador. Este circuito foi implementado com base numa matriz de fotodetectores e componentes electrónicos auxiliares que têm como função obter os valores de luz visível, efectuar a multiplexagem dos sensores da matriz, e enviar os dados para o microcontrolador. Posteriormente foi desenvolvido um firmware para o microcontrolador capaz de efectuar o controlo de todo o sistema, desde a aquisição dos sensores até ao envio dos dados através de comunicação série para uma interface com o utilizador. Os resultados são apresentados ao utilizador de uma forma clara e organizada, permitindo uma análise directa e facilitada destes. Por fim, o sistema foi sujeito a testes de acordo com uma metodologia previamente definida. Nestes testes, o sistema revelou um desempenho fluído, sólido e direto, havendo espaço para a sua optimização, melhoramento e adaptação para novas aplicações

Development and Performance of Kyoto's X-ray Astronomical SOI pixel (SOIPIX) sensor

We have been developing monolithic active pixel sensors, known as Kyoto's X-ray SOIPIXs, based on the CMOS SOI (silicon-on-insulator) technology for next-generation X-ray astronomy satellites. The event trigger output function implemented in each pixel offers microsecond time resolution and enables reduction of the non-X-ray background that dominates the high X-ray energy band above 5--10 keV. A fully depleted SOI with a thick depletion layer and back illumination offers wide band coverage of 0.3--40 keV. Here, we report recent progress in the X-ray SOIPIX development. In this study, we achieved an energy resolution of 300~eV (FWHM) at 6~keV and a read-out noise of 33~e- (rms) in the frame readout mode, which allows us to clearly resolve Mn-K$\alpha$ and K$\beta$. Moreover, we produced a fully depleted layer with a thickness of $500~{\rm \mu m}$. The event-driven readout mode has already been successfully demonstrated.Comment: 7pages, 12figures, SPIE Astronomical Telescopes and Instrumentation 2014, Montreal, Quebec, Canada. appears as Proc. SPIE 9147, Space Telescopes and Instrumentation 2014: Ultraviolet to Gamma Ra

R&D Paths of Pixel Detectors for Vertex Tracking and Radiation Imaging

This report reviews current trends in the R&D of semiconductor pixellated sensors for vertex tracking and radiation imaging. It identifies requirements of future HEP experiments at colliders, needed technological breakthroughs and highlights the relation to radiation detection and imaging applications in other fields of science.Comment: 17 pages, 2 figures, submitted to the European Strategy Preparatory Grou