Optical telescope with 3.75 ◦ field of view and pre-aperture slewing mirror with observation area of 50 ◦ ×120 ◦ for the system of observation of day time asteroids (the SODA project)

В работе предложена оптическая схема широкоугольного телескопа с полем зрения 3.75 ◦ и апертурой 30 см для космической системы обнаружения декаметровых астероидов (проект СОДА). Основная отличительная особенность телескопа - наличие предапертурного плоского зеркала, обеспечивающего область наведения 50 ◦ × 120 ◦ , время перенаведения между соседними площадками составит не более 3 с. Предложен современный КМОП детектор с мелким пикселем. В работе представлены области обзора телескопов проекта СОДА из точки Лагранжа L 1 при использовании двух, трех и четырех телескопов, кратко обсуждены преимущества и недостатки каждого из вариантов. We propose an optical scheme of a telescope with a field of view of 3.75 ◦ and 30 cm aperture for the space system for observation of decameter size asteroids (the SODA project). The main distinctive feature of this telescope is a pre-aperture flat mirror that provides an observation area of 50 ◦ ×120 ◦ and a repointing time between the adjacent fields of less than 3 s. A modern CMOS detector with a small pixel is proposed. Observable sky area when using 2, 3 and 4 telescopes are described. The advantages and disadvantages of each option are briefly discussed.

Advances in 3D Sensor Technology by Using Stepper Lithography

3D pixel sensors aimed at the upgrades of the ATLAS and CMS experiments at the High Luminosity LHC have small pixel size and pretty dense layouts. In addition, modified 3D designs with small pixel size and trenched electrodes in place of columnar electrodes are being developed to optimize the pixel timing performance in view of the LHCb upgrade. The fabrication of these advanced 3D pixels is challenging from the lithographical point of view. This motivated the use of stepper lithography at Fondazione Bruno Kessler in place of a standard mask aligner. The small minimum feature size and high alignment accuracy of stepper allow a good definition of the sensor geometries also in the most critical layouts, so that a higher fabrication yield can be obtained. In this paper, we will present the main design and technological issues and discuss their impact on the electrical characteristics of 3D pixel sensors of different geometries.

Dependence of radiomic features on pixel size affects the diagnostic performance of radiomic signature for the invasiveness of pulmonary ground-glass nodule

Objective: To investigate the effect of reducing pixel size on the consistency of radiomic features and the diagnostic performance of the downstream radiomic signatures for the invasiveness for pulmonary ground-glass nodules (GGNs) on CTs. Methods: We retrospectively collected the clinical data of 182 patients with GGNs on high resolution CT (HRCT). The CT images of different pixel sizes (0.8mm, 0.4mm, 0.18 mm) were obtained by reconstructing the single HRCT scan using three combinations of field of view and matrix size. For each pixel size setting, radiomic features were extracted for all GGNs and radiomic signatures for the invasiveness of GGNs were built through two modeling pipelines for comparison. Results: The study finally extracted 788 radiomic features. 87% radiomic features demonstrated inter pixel size variation. By either modeling pipeline, the radiomic signature under small pixel size performed significantly better than those under middle or large pixel sizes in predicting the invasiveness of GGNs (p’s value <0.05 by Delong test). With the independent modeling pipeline, the three pixel size bounded radiomic signatures shared almost no common features. Conclusions: Reducing pixel size could cause inconsistency in most radiomic features and improve the diagnostic performance of the downstream radiomic signatures. Particularly, super HRCTs with small pixel size resulted in more accurate radiomic signatures for the invasiveness of GGNs. Advances in knowledge: The dependence of radiomic features on pixel size will affect the performance of the downstream radiomic signatures. The future radiomic studies should consider this effect of pixel size.