Μελέτη διαφορικών ενεργών διατομών κατάλληλων για EBS και NRA

Πανέτα, Βαλεντίνα; Paneta, Valentina

dc.contributor.author	Πανέτα, Βαλεντίνα	el
dc.contributor.author	Paneta, Valentina	en
dc.date.accessioned	2015-06-26T08:32:00Z
dc.date.available	2015-06-26T08:32:00Z
dc.date.issued	2015-06-26
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/40888
dc.identifier.uri	http://dx.doi.org/10.26240/heal.ntua.1783
dc.rights	Default License
dc.subject	διαφορική ενεργός διατομή	el
dc.subject	differential cross section	en
dc.subject	θεωρία R-matrix	el
dc.subject	Elastic Backscattering Spectroscopy	en
dc.subject	Nuclear Reaction Analysis	en
dc.subject	Φασματοσκοπία Ελαστικής Οπισθοσκέδασης	el
dc.subject	Ανάλυση με πυρηνικές αντιδράσεις	el
dc.subject	Ανάλυση υλικών με ιοντικές δέσμες	el
dc.subject	Ion Beam Analysis	en
dc.subject	R-matrix theory	en
dc.title	Μελέτη διαφορικών ενεργών διατομών κατάλληλων για EBS και NRA	el
dc.title	Study of differential cross sections suitable for EBS and NRA	en
dc.contributor.department	Department of Physics, NTUA - Tandem laboratory, Institute of Nuclear and Particle Physics, NCSR "Demokritos"	el
heal.type	doctoralThesis
heal.classification	Πυρηνική Φυσική	el
heal.classification	Nuclear Physics	en
heal.language	el
heal.language	en
heal.access	free
heal.recordProvider	ntua	el
heal.publicationDate	2015-03-09
heal.abstract	The Ion Beam Analysis (IBA) techniques are a powerful tool to investigate in a non-invasive way the near-surface composition of a material. To this purpose, the object to be analyzed is used as a target for a beam of accelerated charged particles. The interactions of the beam particles with the atoms (or the nuclei) of the target material induce from the latter the emission of secondary radiation (X-rays, gamma rays, particles), having an energy characteristic of the emitting atom or nucleus. Suitable detectors are then used to collect and discriminate in energy the emitted radiation. In the case of emitted particles their energy also depends on the energy losses both of projectiles and registered particles on the paths traversing by them in the sample before and after the interaction respectively. This makes it possible not only to detect an element but also to determine the depth profile of its concentration in a single measurement. Ion Beam Analysis techniques are thus implemented on a wide variety of applications, ranging from environmental studies, cultural heritage and geology to semiconductor, metallurgy and chemistry. Among the IBA techniques, EBS (Elastic Backscattering Spectroscopy) and NRA (Nuclear Reaction Analysis), depending on the interaction occurring in the target between the accelerated particles and the atomic nuclei, are especially suited for light element detection, which generally constitutes a great challenge in the field. The application of these methods requires the determination of the differential cross sections used in the concentration calculations, over a wide range of energies and detection angles with the highest possible accuracy. The theoretically evaluated cross-section data are the most reliable ones to be used in such analytical studies, since they involve a critical assessment of the available experimentally determined cross sections, followed by a proper tuning of the corresponding nuclear model parameters. The existing experimental data are quite scarce and discrepant in many cases, hindering both their direct use in implementing the aforementioned IBA techniques and the corresponding evaluation process, thus limiting the applicability of both EBS and NRA. My dissertation’s contribution in this field mainly involves the measurement of selected reactions critical for EBS and NRA purposes. Using these reactions, natural magnesium, fluorine and lithium can be accurately determined in near surface layers of materials. Part of my research also involves the development of an experimental procedure, called benchmarking, for the validation of charged particle differential cross section datasets, which is indeed of great importance for all analytical applications. Benchmarking is an integral experiment that needs to 2 be very carefully designed and performed, since a great number of parameters need to be investigated and accurately determined. Benchmarking is actually in many ways critical for the implementation of EBS and NRA techniques in material analysis, besides the validation of differential cross-section data, since it also provides feedback for the adjustment of the parameters of the nuclear model used in the evaluation procedure. Moreover, it can facilitate the extension of the existing evaluations to higher energies, it can help in assigning realistic uncertainties to the cross sections, and it can also indicate recommended experimental datasets to be used in analysis in the absence of theoretically evaluated ones. The theoretical approach of the elastic scattering and particularly the scattering theory, along with the subsequent theoretical models used in the evaluation procedure of the cross section data, is also presented in this dissertation. Namely, the case of the 19F(p,p0) elastic scattering was studied, performing R-matrix calculations with the use of the AZURE code.	en
heal.advisorName	Κόκκορης, Μιχαήλ	el
heal.advisorName	Λαγογιάννης, Αναστάσιος	el
heal.advisorName	Gurbich, Alexander	en
heal.advisorName	Kokkoris, Michael	en
heal.advisorName	Lagoyannis, Anastasios	en
heal.committeeMemberName	Βλαστού-Ζάννη, Ρόζα	el
heal.committeeMemberName	Μισαηλίδης, Παναγιώτης	el
heal.committeeMemberName	Πατρώνης, Νικόλαος	el
heal.committeeMemberName	Chiari, Massimo	en
heal.academicPublisher	Σχολή Εφαρμοσμένων Μαθηματικών και Φυσικών Επιστημών	el
heal.academicPublisherID	ntua
heal.fullTextAvailability	true