Study of the track reconstruction in the FOOT experiment for Hadrontherapy

In adroterapia vengono utilizzati fasci di ioni (protoni e ioni carbonio) per il trattamento di tumori profondi; queste particelle possiedono molti vantaggi rispetto ai fotoni utilizzati nella radioterapia convenzionale. Il profilo dose-profondità di questi ioni è caratterizzato da una bassa dose nel canale di entrata e da un massimo molto pronunciato situato alla fine del loro range, chiamato picco di Bragg, la cui profondità dipende dall'energia del fascio. Inoltre gli ioni più pesanti del protone, come il carbonio o l'ossigeno, mostrano un'efficacia biologica maggiore nella regione del picco di Bragg, aprendo così alla possibilità di trattare anche tumori ipossici. Tuttavia il problema più grande nell'utilizzo di questi ioni è la loro frammentazione nucleare che causa una dose non nulla oltre il picco di Bragg. Nei trattamenti con fasci di protoni invece, è la frammentazione del bersaglio ad essere un problema: una conoscenza corretta e approfondita di questo fenomeno sarebbe davvero importante per valutare la reale efficacia biologica dei protoni. L'esperimento FOOT (FragmentatiOn Of Target) è stato proposto proprio per fare luce su questi aspetti: il suo obiettivo finale è quello di misurare la sezione d'urto dei frammenti pesanti, con Z>2, con un'incertezza massima del 5% e il loro spettro energetico con una risoluzione dell'ordine di 1-2 MeV/u, così da ottenere una migliore caratterizzazione radiobiologica dei protoni. In questa tesi si intende studiare come si determinano i momenti dei frammenti ricostruendo le loro tracce in campo magnetico usando il filtro di Kalman. Inoltre vengono sviluppati e discussi due algoritmi che hanno lo scopo di assegnare correttamente le hit con le tracce

Nuclear fragmentation cross section measurements with the FOOT experiment

Different fields can profit by nuclear fragmentation cross section measurements: among them hadrontherapy and space radioprotection are of particular interest. Hadrontherapy employs high-energy beams of charged particles (protons and heavier ions) to treat deep-seated tumours. In these treatments nuclear interactions have to be considered: beam particles can fragment in the human body releasing a non-zero dose beyond the tumour while fragments of human body nuclei can modify the dose released in healthy tissues. On the radioprotection side, the interest in long-term manned space missions beyond Low Earth Orbit is growing in these years but it has to cope with significant health concerns from radiation in space, necessitating an accurate cross section data description. The FOOT (FragmentatiOn Of Target) experiment was proposed to cover these gaps in data. It was designed to detect, track and identify nuclear fragments and aims to measure double differential cross sections both in angle and kinetic energy which is the most complete information to address existing questions. The FOOT experimental setups, the experimental program and a first cross section analysis of 400 MeV/u 16O beam on Carbon target data acquired in July 2021 at GSI (Darmstadt, Germany) will be presented

Recovery times of riparian vegetation

Riparian vegetation is a key element in a number of processes that determine the ecogeomorphological features of the river landscape. Depending on the river water stage fluctuations, vegetation biomass randomly switches between growth and degradation phases and exhibits relevant temporal variations. A full understanding of vegetation dynamics is therefore only possible if the hydrological stochastic forcing is considered. In this vein, we focus on the recovery time of vegetation, namely the typical time taken by vegetation to recover a well-developed state starting from a low biomass value (induced, for instance, by an intense flood). The analytical expression of the plot-dependent recovery time is given, the role of hydrological and biological parameters is discussed, and the impact of river-induced randomness is highlighted. Finally, the effect of man-induced hydrological changes (e.g., river damming or climate changes) is explored

Convective-absolute nature of ripple instabilities on ice and icicles

Film hydrodynamics is crucial in water-driven morphological pattern formation. A prominent example is given by icicle ripples and ice ripples, which are regular patterns developing on freezing-melting inclined surfaces bounding open-channel flows. By a suitable mathematical model based on conservation principles and the use of the cuspmap method, in this paper we address the convective-absolute nature of these two kinds of instabilities. The obtained results show that icicle ripples, which develop at inverted (overhang) conditions, have subcentimetric wavelengths which are unstable when the Reynolds number of the liquid flow (Re) is small and the supercooling is intensive. With the increase in Re, the instability switches from absolute to convective. Ice ripples instead exhibit the opposite dependance on Re and are highly affected by the surface slope. In addition, the evaluation of the so-called absolute wave number, which is responsible for the asymptotic impulse response, suggests a different interpretation of some recent experiments about ice ripples

Thin-film-induced morphological instabilities over calcite surfaces

Precipitation of calcium carbonate from water films generates fascinating calcite morphologies that have attracted scientific interest over past centuries. Nowadays, speleothems are no longer known only for their beauty but they are also recognized to be precious records of past climatic conditions, and research aims to unveil and understand the mechanisms responsible for their morphological evolution. In this paper, we focus on crenulations, a widely observed ripple-like instability of the the calcite–water interface that develops orthogonally to the film flow. We expand a previous work providing new insights about the chemical and physical mechanisms that drive the formation of crenulations. In particular, we demonstrate the marginal role played by carbon dioxide transport in generating crenulation patterns, which are indeed induced by the hydrodynamic response of the free surface of the water film. Furthermore, we investigate the role of different environmental parameters, such as temperature, concentration of dissolved ions and wall slope. We also assess the convective/absolute nature of the crenulation instability. Finally, the possibility of using crenulation wavelength as a proxy of past flows is briefly discussed from a theoretical point of view

The FOOT experiment: Trigger and Data Acquisition (TDAQ) development and data analysis

Hadrontherapy employs high-energy beams of charged particles (protons and heavier ions) to treat deep-seated tumours: these particles have a favourable depth-dose distribution in tissue characterized by a low dose in the entrance channel and a sharp maximum (Bragg peak) near the end of their path. In these treatments nuclear interactions have to be considered: beam particles can fragment in the human body releasing a non-zero dose beyond the Bragg peak while fragments of human body nuclei can modify the dose released in healthy tissues. These effects are still in question given the lack of interesting cross sections data. Also space radioprotection can profit by fragmentation cross section measurements: the interest in long-term manned space missions beyond Low Earth Orbit is growing in these years but it has to cope with major health risks due to space radiation. To this end, risk models are under study: however, huge gaps in fragmentation cross sections data are currently present preventing an accurate benchmark of deterministic and Monte Carlo codes. To fill these gaps in data, the FOOT (FragmentatiOn Of Target) experiment was proposed. It is composed by two independent and complementary setups, an Emulsion Cloud Chamber and an electronic setup composed by several subdetectors providing redundant measurements of kinematic properties of fragments produced in nuclear interactions between a beam and a target. FOOT aims to measure double differential cross sections both in angle and kinetic energy which is the most complete information to address existing questions. In this Ph.D. thesis, the development of the Trigger and Data Acquisition system for the FOOT electronic setup and a first analysis of 400 MeV/u 16O beam on Carbon target data acquired in July 2021 at GSI (Darmstadt, Germany) are presented. When possible, a comparison with other available measurements is also reported.L’adroterapia è una tecnica di radioterapia esterna nella quale vengono utilizzati fasci di ioni (protoni e ioni più pesanti) ad alta energia per il trattamento di tumori profondi: tali particelle hanno una distribuzione dose-profondità nel tessuto molto favorevole, caratterizzata da un basso rilascio di dose nel canale di entrata e un massimo pronunciato (picco di Bragg) vicino alla fine del loro percorso. In tali trattamenti devono essere prese in considerazione anche le interazioni nucleari: le particelle del fascio possono frammentare nel corpo umano rilasciando una dose non nulla oltre il picco di Bragg mentre i frammenti dei nuclei del paziente possono modificare la dose rilasciata nei tessuti sani. L’entità di tali effetti è attualmente oggetto di studio vista l’assenza di misure sulle sezioni d’urto di interesse. Anche il campo della radioprotezione spaziale può trarre benificio da queste misure poiché i rischi per la salute causati dalla radiazione spaziale rimangono un grande problema da affrontare: per questo motivo si studiano modelli di rischio che attualmente risentono della significativa mancanza di dati sulle sezioni d’urto. L’esperimento FOOT (FragmentatiOn Of Target) è composto da due apparati indipendenti e complementari, una Emulsion Cloud Chamber e un apparato elettronico composto da alcuni rivelatori che forniscono misure ridondanti delle quantità cinematiche dei frammenti nucleari prodotti dalle interazioni tra il fascio ed il bersaglio. FOOT ha l’obiettivo di misurare le sezioni d’urto differenziali sia in angolo che in energia cinetica, informazioni fondamentali per rispondere ai problemi aperti. In questa tesi sono presentati sia lo sviluppo del sistema di trigger e acquisizione dati (TDAQ) per l’apparato elettronico dell’esperimento sia una prima analisi dei dati del fascio di 16O a 400 MeV/u su un bersaglio di carbonio acquisiti a luglio 2021 presso il GSI (Darmstadt, Germania) oltre ad un confronto, quando possibile, con altre misure attualmente disponibili

REAL-TIME MEASUREMENT FAULT DETECTION AND REMOTE CONTROL IN A MOUNTAIN WATER SUPPLY SYSTEM

This work presents an algorithm for real-time fault detection in the SCADA system of a modern water supply system (WSS) in an Italian Alpine Valley. By means of both hardware and analytical redundancy, the proposed algorithm compares data and isolates faults on sensors through the residual analysis. Moreover, the algorithm performs a real- time selection of the most reliable measurements for the automated control of the WSS operations. A coupled model of the hydraulic and remote-control system was developed to test the effectiveness of the proposed algorithm. Simulations showed that error detection and measurement assessment are crucial for the safe operation of the WSS

Effect of river flow fluctuations on riparian vegetation dynamics: Processes and models

Several decades of field observations, laboratory experiments and mathematical modelings have demonstrated that the riparian environment is a disturbance-driven ecosystem, and that the main source of disturbance is river flow fluctuations. The focus of the present work has been on the key role that flow fluctuations play in determining the abundance, zonation and species composition of patches of riparian vegetation. To this aim, the scientific literature on the subject, over the last 20 years, has been reviewed. First, the most relevant ecological, morphological and chemical mechanisms induced by river flow fluctuations are described from a process-based perspective. The role of flow variability is discussed for the processes that affect the recruitment of vegetation, the vegetation during its adult life, and the morphological and nutrient dynamics occurring in the riparian habitat. Particular emphasis has been given to studies that were aimed at quantifying the effect of these processes on vegetation, and at linking them to the statistical characteristics of the river hydrology. Second, the advances made, from a modeling point of view, have been considered and discussed. The main models that have been developed to describe the dynamics of riparian vegetation have been presented. Different modeling approaches have been compared, and the corresponding advantages and drawbacks have been pointed out. Finally, attention has been paid to identifying the processes considered by the models, and these processes have been compared with those that have actually been observed or measured in field/laboratory studies

A Dynamic Manipulation Strategy for an Intervention Autonomous Underwater Vehicle

This paper presents the modelling and the control architecture of an Autonomous Underwater Vehicle for Intervention (I-AUV). Autonomous underwater manipulation with free-floating base is still an open topic of research, far from reaching an industrial product. Dynamic manipulation tasks, where relevant vehicle velocities are required during manipulation, over an additional challenge. In this paper, the accurate modelling of an I-AUV is described, not neglecting the interaction with the fluid. A grasp planning strategy is proposed and integrated in the control of the whole system. The performances of the I-AUV have been analysed by means of simulations of a dynamic manipulation task