Study, design and test of the Target - Ion Source system for the INFN SPES facility

Since the beginning of the twentieth century nuclear physics explores the behaviour and the stability of nuclei, each time facing new scientific and technological challenges. The complex technologies specifically developed to support research in the field of nuclear physics have often led to important applications in medicine, industry, applied physics, influencing sometimes in a deep way the society: the birth of the “web” at CERN is an emblematic example. Over the years Europe has become a leader in the field of nuclear physics research: CERN is the world's largest particle physics laboratory, situated in the Northwest suburbs of Geneva on the Franco–Swiss border, and Italy, with INFN (Istituto Nazionale di Fisica Nucleare), is one of its main members. In Italy, one of the most important projects supported by INFN is the so-called SPES (Selective Production of Exotic Species) project that is intended to develop a facility for the production of radioactive ion beams at Legnaro National Laboratories (Padua, Italy). In particular the SPES facility will produce neutron rich nuclei with mass in the range 80-160, to use for forefront research in nuclear physics and for many applications in different fields of science. The core of the project is constituted by the target – ion source system and in this work its study, design and test are presented. Chapter 1 gives a general overview of the SPES project and its scientific context whereas chapter 2 presents some details of the SPES production area that is composed of the target – ion source system and all the experimental apparatus needed for its functioning. Chapters 3 and 4 describe in detail the study, the design and the experimental tests performed for the SPES target and for the SPES ion sources, respectively. Once described separately the target and the ion source, they are studied together in chapter 5, observing with particular attention their reciprocal effects. In the final part of the thesis chapter 6 reports the description of the on-line test of the uranium carbide SPES target prototype carried on at the HRIBF facility (ORNL, USA).Sin dagli inizi del ventesimo secolo la fisica nucleare esplora il comportamento e la stabilità dei nuclei atomici, affrontando di volta in volta nuove sfide scientifiche e tecnologiche. Le complesse tecnologie sviluppate appositamente per supportare la ricerca nel campo della fisica nucleare hanno spesso condotto ad importanti applicazioni in medicina, a livello industriale, in fisica applicata, influenzando talvolta in modo profondo gli usi e i costumi della società: la nascita del “web” presso il CERN di Ginevra costituisce un esempio emblematico. Nel corso degli ultimi anni l’Europa è diventata leader nel campo della fisica nucleare: il CERN è il più grande laboratorio di fisica delle particelle al mondo, situato nella periferia a Nordovest di Ginevra in prossimità del confine Franco-Svizzero, e l’Italia, con l’INFN (Istituto Nazionale di Fisica Nucleare), è uno dei suoi membri principali. In Italia, uno dei più importanti progetti supportati dall’INFN è il progetto SPES (Selective Production of Exotic Species) che prevede la costruzione di una facility per la produzione di fasci radioattivi presso i Laboratori Nazionali di Legnaro (Padova). In particolare la facility SPES produrrà nuclei ricchi di neutroni con masse comprese nel range 80-160, da impiegare per la ricerca di base in fisica nucleare e per numerose altre applicazioni in ambito scientifico. Il cuore del progetto è costituito dal sistema target – sorgente di ionizzazione ed in questo lavoro ne vengono presentati lo studio, la progettazione ed i corrispettivi test sperimentali. Il capitolo 1 fornisce una presentazione generale del progetto SPES e del contesto scientifico ad esso legato mentre il capitolo 2 presenta alcuni dettagli dell’area di produzione SPES composta dal sistema target – sorgente di ionizzazione e da tutti gli apparati sperimentali necessari al suo funzionamento. I capitoli 3 e 4 descrivono in dettaglio lo studio, la progettazione ed i test sperimentali svolti rispettivamente per il target SPES e per le sorgenti di ionizzazione SPES. Una volta presentati separatamente il target e la sorgente di ionizzazione, tali componenti vengono studiati in modo accoppiato a livello del capitolo 5, prestando particolare attenzione agli effetti reciproci. Nella parte finale della tesi il capitolo 6 riporta la descrizione dei test on-line sul prototipo del target SPES in carburo di uranio svolti presso l’ HRIBF facility dei Laboratori Nazionali di Oak Ridge (USA)

Introduzione all\ue2\u20ac\u2122analisi termica con il codice di calcolo Ansys

Testo Didattic

Introduction to the static structural analysis with ansys\uae numerical code

The purpose of this guide is to introduce the user to the static structural analysis using the finite element code ANSYS\uf0d2. Being an accurate on-line manual available, the present tutorials have been prepared as a guideline introducing to the structural analysis, by pre-senting some examples concerning the element types typically adopted in practical applica-tions. Each example shows all stages of the analysis procedure with a description of the Ansys commands starting from geometric modelling up to the analysis of results. Many students have contributed to the preparation of this work, both during drafting and during a subsequent check of the described procedures. The authors wish to thank Michele Cagol and, in particular, David Locas for their contribution. This updated edition has become necessary due to the new element library available in the ANSYS \uae code ver-sion 14. We would like to thank Prof. Michele Ciavarella and his student Antonio Balsamo of the Politecnico di BARI, for the help in the english translation

Thermal-electric numerical simulation of a surface ion source for the production of radioactive ion beams

In afacilityfortheproductionofradioactiveionbeams(RIBs),thetargetsystemandtheionsourceare the mostcriticalobjects.InthecontextoftheSelectiveProductionofExoticSpecies(SPES)project,a protonbeamdirectlyimpingesaUraniumCarbideproductiontarget,generatingapproximately1013 fissionspersecond.Theradioactiveisotopesproducedbythe 238U fissionsarethendirectedtotheion sourcetoacquireachargestate.Afterthat,theradioactiveionsobtainedaretransported electrostaticallytothesubsequentareasofthefacility.Inthisworkthesurfaceionsourceatpresent adoptedfortheSPESprojectisstudiedbymeansofbothanalyticalandnumericalthermal\u2013electric models.Thetheoreticalresultsarecomparedwithtemperatureandelectricpotentialdifference measurements

Introduzione all\ue2\u20ac\u2122analisi strutturale statica con il codice di calcolo Ansys

Testo Didattic

Electrical-thermal-structural finite element simulation and experimental study of a plasma ion source for the production of radioactive ion beams

The production target and the ion source constitute the core of the selective production of exotic species (SPES) facility. In this complex experimental apparatus for the production of radioactive ion beams, a 40 MeV, 200 \u3bcA proton beam directly impinges a uranium carbide target, generating approximately 1013 fissions per second. The transfer line enables the unstable isotopes generated by the 238U fissions in the target to reach the ion source, where they can be ionized and finally accelerated to the subsequent areas of the facility. In this work, the plasma ion source currently adopted for the SPES facility is analyzed in detail by means of electrical, thermal, and structural numerical models. Next, theoretical results are compared with the electric potential difference, temperature, and displacement measurements. Experimental tests with stable ion beams are also presented and discussed

Thermal and Structural Characterization of a Titanium Carbide/Carbon Composite for Nuclear Applications

In the framework of ISOL (isotope separation on-line) facilities, porous carbides are among the most employed target materials for the production of radioactive ion beams for research. As foreseen by the ISOL technique, a production target is impinged by an energetic particle beam, inducing nuclear reactions from such an interaction. The resulting radionuclides are subsequently released, thanks to the high target working temperature (1600–2000 °C); ionized; and extracted into a beam. Since the target microstructure and porosity play a fundamental role in the radionuclide release efficiency, custom-made target materials are often specifically produced, resulting in unknown thermal and structural properties. Considering that such targets might undergo intense thermal stresses during operation, a thermal and structural characterization is necessary to avoid target failure under irradiation. In the presented work, a custom-made porous titanium carbide that was specifically designed for application as an ISOL target was produced and characterized. The thermal characterization was focused on the evaluation of the material emissivity and thermal conductivity in the 600–1400 °C temperature range. For the estimation of a reference material tensile stress limit, the virtual thermoelastic parameter approach was adopted. In particular, for the aforementioned temperature range, an emissivity between 0.7 and 0.8 was measured, whereas a thermal conductivity between 8 and 10 W/mK was estimated

Thermal-electric coupled-field finite element modeling and experimental testing of high-temperature ion sources for the production of radioactive ion beams

In isotope separation on line facilities the target system and the related ion source are two of the most critical components. In the context of the selective production of exotic species (SPES) project, a 40 MeV 200 \u3bcA proton beam directly impinges a uranium carbide target, generating approximately 1013 fissions per second. The radioactive isotopes produced in this way are then directed to the ion source, where they can be ionized and finally accelerated to the subsequent areas of the facility. In this work both the surface ion source and the plasma ion source adopted for the SPES facility are presented and studied by means of numerical thermal-electric models. Then, numerical results are compared with temperature and electric potential difference measurements, and finally the main advantages of the proposed simulation approach are discussed. C 2015 AIP Publishing LLC