1,720,973 research outputs found
Design, Testing and Calibration of the GAPS Experiment Si(Li) Tracker Readout ASIC: From the First Flight Campaign Toward the Second Mission Upgrade
No full textIl General Antiparticle Spectrometer è un esperimento a pallone stratosferico concepito per effettuare tre voli di lunga durata dall’Antartide, con l’obiettivo di ricercare antinuclei cosmici a bassa energia, in particolare antideuteroni, come canale indiretto per lo studio della materia oscura. La tecnica di rivelazione si basa sulla formazione e sul decadimento di atomi esotici, riconoscibili attraverso l’emissione di raggi x caratteristici e la successiva annichilazione in particelle secondarie. Al cuore dello strumento si trova il tracciatore al silicio, costituito da rivelatori al silicio drogati al litio, operati a –40°C e letti da un circuito integrato dedicato, denominato SLIDER32, realizzato in tecnologia CMOS a 180 nm. La tesi descrive le attività di integrazione, calibrazione e validazione dell’elettronica di lettura del tracciatore basata su SLIDER32. La caratterizzazione in laboratorio di un modulo del tracciatore, condotta con una sorgente di Americio-241 e con muoni cosmici, è stata affiancata da prove di calibrazione e test dell’intero tracciatore nella configurazione prevista per il primo volo, che hanno portato alla prima acquisizione di uno spettro a raggi x da una sorgente di Cadmio-109. Queste attività hanno fatto parte della fase di integrazione e test dell’esperimento, culminata con l’assemblaggio completo dello strumento e la sua validazione durante la campagna antartica del 2024. Sulla base di questa esperienza è stato progettato e realizzato un nuovo circuito integrato, sviluppato come evoluzione di SLIDER32: il chip ANTARES4, fabbricato in tecnologia CMOS a 65 nm. Il dispositivo integra otto canali analogici fino allo stadio di shaping e introduce soluzioni innovative per la compressione dinamica del segnale mediante transistori MOS a soglia dinamica, insieme a un circuito migliorato di compensazione della corrente di leakage all’ingresso del preamplificatore. La caratterizzazione di laboratorio ha fornito una prima validazione di queste soluzioni progettuali, ponendo le basi per il sistema di lettura di nuova generazione che sarà impiegato nel secondo volo dell’esperimento.The General Antiparticle Spectrometer is a balloon-borne experiment designed to perform three long-duration flights from Antarctica to search for low-energy cosmic antinuclei, in particular antideuterons, as an indirect probe of dark matter. Its detection method is based on the formation and decay of exotic atoms, identified through the emission of characteristic x-rays and the subsequent annihilation into secondary particles. At the core of the instrument is the silicon tracker, composed of lithium-drifted silicon detectors operated at −40°C and read out by a custom application-specific integrated circuit, SLIDER32, implemented in 180 nm CMOS technology. This thesis reports on the integration, calibration, and validation of the SLIDER32-based tracker readout electronics. Laboratory characterization of a single tracker module with an Americium-241 source and cosmic muons was complemented by calibration and testing of the full tracker in its flight configuration, leading to the first x-ray spectrum acquisition from a Cadmium-109 source. These activities formed part of the integration and testing phase of the experiment for the first flight, which culminated in the complete instrument assembly and validation during the Antarctic campaign of 2024. Building on this experience, the work introduces the design and characterization of a new prototype integrated circuit conceived as an upgrade to SLIDER32: the ANTARES4 chip, fabricated in 65 nm CMOS technology. The device integrates eight analog channels up to the shaping stage and implements innovative solutions for dynamic signal compression exploiting dynamic-threshold MOS transistors, together with an improved detector leakage current compensation circuit at the preamplifier input. Its laboratory characterization provides a first validation of these design choices, laying the foundations for the next-generation tracker readout system to be adopted in the second flight of the experiment
Design of the ANTARES4 Readout ASIC for the Second Flight of the GAPS Experiment: Motivations and Requirements
Full text linkThe General AntiParticle Spectrometer is a balloon borne experiment designed to search for low energy cosmic ray antinuclei as a potential indirect signature of dark matter. Over the course of at least three long duration flights over Antarctica, it will explore the sub 250 MeV per nucleon energy range with sensitivity to antideuterons and antihelium, while also extending antiproton measurements below 100 MeV. The instrument features a tracker built from more than one thousand lithium drifted silicon detectors, each read out by a dedicated custom integrated circuit. With the first flight scheduled for the austral summer of 2025, a new prototype chip, ANTARES4, has been developed using a commercial 65 nm complementary metal oxide semiconductor process for use in the second flight. It integrates eight independent analog channels, each incorporating a low noise charge sensitive amplifier with dynamic signal compression, a CR RC shaping stage with eight selectable peaking times, and on chip calibration circuitry. The charge sensitive amplifier uses metal oxide semiconductor feedback elements with voltage dependent capacitance to support the wide input energy range from 10 keV to 100 MeV. Four alternative feedback implementations are included to compare performance and design trade offs. Leakage current compensation up to 200 nA per detector strip is provided by a Krummenacher current feedback network. This paper presents the design and architecture of ANTARES4, highlighting the motivations, design drivers, and performance requirements that guided its development
Low-Noise Wide Dynamic Range Charge Sensitive Amplifier in 65 nm CMOS Technology for the Second Flight of the GAPS Experiment
No full textThis work describes a low-noise charge sensitive amplifier designed in a commercial 65nm CMOS technology for the second flight of the General AntiParticle Spectrometer balloon experiment, aimed at the indirect search of dark matter. The circuit has been developed as part of the upgrade of the chip employed in the readout of the lithium-drifted silicon detectors of the inner tracker and features dynamic signal compression to cope with the wide input dynamic range. A novel solution using dynamic threshold MOSFETs for the non-linear feedback capacitor implementation has been investigated. The paper will discuss the amplifier architecture, with a focus on the input and feedback device design and the relevant simulation results
A 32-Channel Readout ASIC for X-Ray Spectrometry and Tracking in the GAPS Experiment
No full textThis work describes the architecture and the experimental results from the characterization of a 32-channel
mixed-signal application-specific integrated circuit (ASIC) developed for the readout of the lithium-drifted silicon (Si(Li)), detectors of the general antiparticle spectrometer (GAPS) experiment dedicated to searching for dark matter. The instrument is designed for the identification of antiprotons, antideuterons, and antihelium nuclei from cosmic rays during an Antarctic balloon mission scheduled for late 2024. A full-custom integrated
circuit, named SLIDER32 (32-channel Si-Li detector readout) ASIC, has been produced in a commercial 180-nm CMOS technology. The ASIC comprises 32 low-noise analog readout channels featuring dynamic signal compression to comply with the wide input range, an 11-bit successive approximation register
(SAR) analog-to-digital converter (ADC), and a digital back-end section which is responsible for channel setting and for sending digital information to the data acquisition system (DAQ). The circuit design criteria and the experimental results are discussed in this article
X-ray and Particle Detection with the Si(Li) Tracker Module of the GAPS Experiment
No full textThis work describes the architecture and the experimental results from the characterization of the lithium-drifted silicon (Si(Li)) detector module, which constitutes the building block of the tracker in the General Antiparticle Spectrometer (GAPS) experiment to search for dark matter. The instrument is designed for the identification of low-energy cosmic antinuclei (antiprotons, antideuterons and antihelium) to be performed during an Antarctic long-duration balloon flight scheduled for late 2025. The GAPS Si(Li) tracker, that is the core of the instrument, is the assembly of 252 modules, each comprised of four Si(Li) detectors and a full custom integrated circuit designed for detector readout and produced in a commercial 180 nm planar CMOS technology. A general overview of the detector module architecture and its components is provided, together with a description of the test setup and the experimental results obtained from the characterization of the low-noise analog readout channel. In order to verify the effective operation of the entire module, results concerning the detection of X-rays from a 241Am source and cosmic muons are also provided
A mixed-signal processor for X-ray spectrometry and tracking in the GAPS experiment
No full textThis paper reports the design and experimental results from the characterization of an integrated circuit developed for the readout of the X-ray spectrometer and tracking system of the General AntiParticle Spectrometer (GAPS) balloon mission. GAPS will search for an indirect signature of dark matter through the detection of low-energy (<0.25 GeV/n) cosmic-ray antiprotons, antideuterons and antihelium nuclei. The ASIC, named SLIDER32 (32 channels Si-LI DEtector Readout ASIC), was fabricated in a 180 nm CMOS technology and is comprised of 32 analog readout channels, an 11-bit SAR ADC and a digital back-end section which is responsible for defining channel settings and for sending digital information to the data acquisition system. The core of the ASIC is a low-noise analog channel implementing a dynamic signal compression which makes the chip suitable for resolving both X-rays in the range of 20 to 100 keV and charged particles with energy deposition of up to 100 MeV. It features an energy resolution of 4 keV FWHM in the 20–100 keV range with a 40 pF detector capacitance, to clearly distinguish X-rays from antiprotonic or antideuteronic exotic atoms. The readout electronics of the ASIC will run at a temperature of about –40 °C, complying with a detector leakage current of the order of 5–10 nA per strip
Index Air Quality Monitoring for Light and Active Mobility
Full text linkLight and active mobility, as well as multimodal mobility, could significantly contribute to decarbonization. Air quality is a key parameter to monitor the environment in terms of health and leisure benefits. In a possible scenario, wearables and recharge stations could supply information about a distributed monitoring system of air quality. The availability of low-power, smart, low-cost, compact embedded systems, such as Arduino Nicla Sense ME, based on BME688 by Bosch, Reutlingen, Germany, and powered by suitable software tools, can provide the hardware to be easily integrated into wearables as well as in solar-powered EVSE (Electric Vehicle Supply Equipment) for scooters and e-bikes. In this way, each e-vehicle, bike, or EVSE can contribute to a distributed monitoring network providing real-time information about micro-climate and pollution. This work experimentally investigates the capability of the BME688 environmental sensor to provide useful and detailed information about air quality. Initial experimental results from measurements in non-controlled and controlled environments show that BME688 is suited to detect the human-perceived air quality. CO2 readout can also be significant for other gas (e.g., CO), while IAQ (Index for Air Quality, from 0 to 500) is heavily affected by relative humidity, and its significance below 250 is quite low for an outdoor uncontrolled environment
The 32 Analog Channels Readout for the Long-Flight GAPS Balloon Experiment Tracking System
No full textThe paper describes the main results of the characterization of the flight ASIC developed for the readout of a lithium-drifted silicon, Si(Li), detector-based tracker. The system aims to detect indirect signatures of dark matter through the identification of low-energy (<0.25GeV/n) cosmic-ray antiprotons, antideuterons, and antihelium. This instrument is developed in the frame of the GAPS (General AntiParticle Spectrometer) balloon experiment. The developed electronics consists of a 32-channels mixed-signal ASIC, designed in a commercial 180 nm CMOS technology and an ad-hoc front-end board (FEB). Data from charged particle detection are also reported
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
