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Backes, Laura Beatriz. "Voz & emoção : provocações a partir de Wolfsohn, Roy Hart e Pantheatre." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2010. http://hdl.handle.net/10183/26996.
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Esta dissertação se propõe a discutir princípios e identificar alguns procedimentos técnicos que provoquem a descoberta, particularmente por atores e bailarinos, de novos territórios de vocalidade, que contribuam para enriquecer a construção da poética cênica. Considerando a emoção como elemento fundamental na descoberta de possibilidades para a voz, o estudo parte das pesquisas pioneiras de Alfred Wolfsohn (1896-1962) e de seu aluno Roy Hart (1926-1975) para se concentrar nas práticas pedagógicas do Pantheatre, companhia fundada na França por Enrique Pardo junto a outros integrantes originais do Roy Hart Theatre (1962-1986). Além da pesquisa bibliográfica, a reflexão fundamentou-se na observação participante de dois workshops intensivos, ministrados por integrantes do Pantheatre, em entrevistas realizadas com o próprio Enrique Pardo e, ainda, na transposição de algumas das práticas pedagógicas então vivenciadas naqueles workshops ao treinamento do Grupo Experimental de Dança e do Grupo Experimental de Teatro da Secretaria Municipal da Cultura de Porto Alegre (SMC-PMPA). A base teórica centra-se nos referenciais do próprio Pantheatre, mas vale-se também de um olhar transdisciplinar ao encontrar auxílio em reflexões advindas da filosofia, da psicologia e das neurociências.This paper aims at discussing principles and identifying some technical procedures to give support, particulary for actors and dancers to find alternatives vocal territorier in order to enrich the scenic poetic construction. Considering the emotion as a fundamental element in the exploring new possibilities of the voice, this study start on the pioneering researches by Alfred Wolfsohn (1896-1962) an his pupil Roy Hart (1926-1975) to end focusing on the pedagogical practices by Pantheatre, a company founded in France by Enrique Pardo and some other original members from the Roy Hart Theatre (1962-1986). Our research is based on the bibliographical research and also on our participative observation at two intensive workshops conducted by Pantheatre members, as well as on interviews carried out with Enrique Pardo himself, but mainly on the transposition of some pedagogical practices from those workshops to the training of experimental dancing and drama groups at the Cultural Dept./Secretariat of Porto Alegre City (“Secretaria Municipal da Cultura/SMC-POA”). The theoretical basis is centered in the own Pantheatre´s references, but it has also been provided with a transversal look as it takes some recent debates in Philosophy, Psychology and Neurosciences into consideration, required by the complexity of our object.
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Colomb, Laurent. "Le Roy Hart Theatre : contribution à une étude pluridisciplinaire de la voix." Paris 8, 2000. http://www.theses.fr/2000PA081840.
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Le @Roy Hart Theatre entretient avec la voix une relation inattendue aux multiples incidences. Ses applications relèvent tout à la fois des domaines du chant, de la thérapie et du théâtre. Elles sont l'aboutissement d'une recherche méthodique et continuelle sur la voix qui couvre une période de près d'un siècle. Cette relation polyvalente à la voix a pour point de départ le traumatisme psychique dont fut victime Alfred Wolfsohn, brancardier sur les charniers de la guerre 14-18. Partant du pouvoir d'expression de la voix, il fixe les bases fondamentales d'une cure par le chant dont il évalue personnellement l'efficacité. L'apport capital de la psychologie jungienne l'entraîne à composer une table des correspondances psycho-tonales, ce qui inscrit son action dans le sillon de l'ésotérisme musical. . .
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Chiochetta, Letícia. "A criação da cena teatral à luz de Alfred Wolfsohn e Roy Hart." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/27/27155/tde-28012014-115432/.
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Esta pesquisa teórico-prática realiza um estudo do pensamento e dos princípios de trabalho de dois importantes artistas e pesquisadores da voz ainda pouco conhecidos no universo das Artes Cênicas no Brasil: o alemão Alfred Wolfsohn e, seu discípulo, o ator Roy Hart. Wolfsohn desenvolveu, após uma experiência traumática de guerra, uma pesquisa aprofundada sobre a expressão humana através da voz. Já Hart aplicou, à sua maneira, os ensinamentos de Wolfsohn no campo teatral. Esta dissertação de mestrado efetiva ainda uma investigação prática à luz dos fundamentos propostos por esses artistas. Sua contribuição pode ser útil para que o ator vislumbre possibilidades de trabalho exploratório sobre si mesmo, partindo do alicerce corpo/voz enquanto unidade expressiva, além de colaborar com a formação integral do ator.This research makes a theoretical and practical study of thinking and working principles of two important artists and researchers of the voice still little known in the world of Performing Arts in Brazil: the German Alfred Wolfsohn and his disciple, actor Roy Hart. Wolfsohn developed, after a traumatic experience in the war, a thorough research on the human expression through the voice. Hart applied, in its own way, the teachings of Wolfsohn in the theatrical field. This dissertation also realizes a practical research in the light of the grounds proposed by these artists. His contribution can be useful for the actor to have a glimpse of the possibilities of exploratory work on him/herself departing of the body/voice foundation as an expressive unity, as well as collaborating with the actor\'s whole formation.
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Meehan, Niall. "Tuning out the troubles in southern Ireland : revisionist history, censorship and problematic Protestants." Thesis, University of Bath, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.683549.
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This thesis is an examination of the influence and impact of the ‘Troubles’ in Northern Ireland, post 1968, on the practice of Irish history, on southern Irish broadcast media and on the southern Irish modernisation process. I will examine the uneasy and contested transition in systems of hegemony in a society where the state is not coterminous with perceptions of nationhood, where society is anxiously suspended between conservation of its existence and popular nationalist aspirations, where southern economic dependency interacted uneasily with northern political instability and sectarianism. The thesis examines the ‘Ulsterisation’ of the War of Independence by some historians and its aftermath as an ideological project. It pays particular attention, using the case-study method, to the imposition of a sectarian character on republican forces during the war of independence by the highly influential Newfoundland historian Peter Hart, and will explain why this research is ideologically problematic within Irish historiography. I will link this to (in a second case-study) the project undertaken in the early 1970s by Irish government minister (also an academic historian and political scientist) Conor Cruise O’Brien to undermine and eradicate from popular awareness secular anti-imperialist aspects of Irish nationalist consciousness, primarily through, in case-study three, the imposition of broadcasting censorship and support for repression. I question O’Brien’s positing of a ‘Catholic nationalism’ as an overarching basis for Irish statehood by, in case-study four, an examination the largely unexplored socio-economic position of Protestants in southern Ireland and the forms of social control imposed on and within that community. The thesis examines how official reaction to the conflict combined repression and broadcasting censorship during the 1970s to revise popular perceptions of Irish history and Irish society. Control of understanding of the present was combined with attempts to take control of perceptions of the past, in order to circumscribe the parameters of what is feasible in the present, so as to preserve the socio-economic status quo. It specifically explores the impact of the post 1968 Northern Ireland conflict on: • The attempt by proponents of Irish revisionist historiography to portray Irish resistance to British rule as ‘Catholic nationalism’ and as a mirror image generally of Ulster unionist sectarianism; in the context of • The simultaneous transformational change of economic direction in the southern Irish economy and society, which imparted to this project increased impetus, opportunity and political scope.
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Olivares, del Real Paloma. "Hare api Hana Roa : Centro educativo Hanga Roa." Tesis, Universidad de Chile, 2012. http://repositorio.uchile.cl/handle/2250/111608.
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Memoria (arquitecto)No autorizada por el autor para ser publicada a texto completo
La educación es esencial para generar una serie de cambios. En el caso de Isla de Pascua, además de potenciar directamente la cultura Rapanui, hay formas indirectas para poner en valor esta misma, ya que puede permitir la disminución de la dependencia del continente, teniendo personas calificadas en la isla para hacer las tareas de la isla, lo que significa importar menos mano de obra del continente por ejemplo, lo que permitiría un cierto grado de protección para la isla, puesto que hoy con las migraciones tanto de turistas como de trabajadores se ha generado un choque cultural, además de no dar abasto con la población migrante. Este proyecto viene a ser la primera etapa de un proyecto educacional para Rapa Nui, complementando la ya existente Aldea Educativa (liceo técnico-profesional y humanista-científico municipal). Entonces el fin último del proyecto es generar un proyecto educacional que contemple los lineamientos de la reforma educacional chilena (1997) con los ojos de la cultura Rapanui.
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Kim, Victoria. "Hard X-ray test objects." Thesis, KTH, Tillämpad fysik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-233228.
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Court, A. J. "Hard X-ray astronomy from balloon altitudes." Thesis, University of Southampton, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.377796.
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Spooner, Neil John Curwen. "New techniques in hard X-ray astronomy." Thesis, Imperial College London, 1986. http://hdl.handle.net/10044/1/38166.
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Lawson, Anthony J. "The hard X-ray emission of quasars." Thesis, University of Leicester, 1995. http://hdl.handle.net/2381/35714.
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The analysis of observations of 50 radio-loud and radio-quiet quasars made by the X-ray satellite Ginga is presented. The spectra, the most accurate and sensitive yet in the 2-20 keV band, provide a unique opportunity to study the hard X-ray emission from these faint, though highly luminous objects. The properties of the X-ray continuum are compatible with previous studies, and reveal a significant measured spread on the spectral index, which is unlikely to be due to spectral variability or to the radio heterogenity of the sample, indicating a true variety of spectral index amongst objects. The flux variability shown by the radio-loud objects is greater than that shown by the radio-quiet objects, but there is no indication of any differences in spectral variability, which is generally low. There is a strong relationship present between the X-ray spectral index and radio loudness, with radio-quiet quasars on average having softer spectra. The spectral index of the radio- loud objects appears to depend on orientation, with objects having the jet closer to sky plane showing steeper spectra than those pointed more towards the Earth. A number of the spectra show features, with non-Galactic absorbtion and Fe Ka line emission being detected. Spectral flattening above 10 keV reported for Seyfert galaxies and attributed to Compton 'reflection' is not strongly supported. The observed difference in the spectral distributions of the radio-quiet quasars and Seyfert galaxies can be accounted for by the absence of warm absorbing material in some objects. The results presented are consistent with current unified models, and with the idea of relativistically beamed X-ray emission in the radio-loud objects. It is likely that more than one mechanism contributes to the beamed emission, with the spectra of these objects depending on orientation, and on the relative luminosities of the non-thermal and thermal continua.
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Mullerworth, Stephen Derek. "Position sensitive detectors for hard X-ray and gamma-ray astronomy." Thesis, University of Southampton, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386646.
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Pleasants, Ian Blair. "Detector elements for hard X-ray and gamma-ray astronomy applications." Thesis, University of Southampton, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262152.
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Fraser-Mitchell, J. N. "An imaging detector for hard X-ray astronomy." Thesis, University of Southampton, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383420.
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Parisi, Pietro <1982>. "Multiwavelength studies of hard X-ray selected sources." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3775/.
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Bale, Greg. "CdZnTe radiation detectors for hard X-ray astronomy." Thesis, University of Leicester, 2001. http://hdl.handle.net/2381/30645.
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This thesis is concerned with the development of CdZnTe compound semiconductor detectors for hard X-ray astronomy. The advent of multilayer coated focusing optics for hard X-rays creates the need for compact solid-state X-ray detectors with substantial quantum efficiency above 10 keV. CZT is a material with the necessary properties to meet the requirements. Excellent results from commercially obtained CdZnTe detectors are presented in Chapter 4 of this work. Low-noise preamplifiers and Peltier coolers were employed to obtain high-resolution X-ray and gamma-ray spectra over the 2 - 60 keV energy range. 55Fe spectra have been acquired with a resolution of < 218eV FWHM and peak-to-background ratios in excess of 200:1. Data have been obtained at a range of energies to enable measurements of fundamental properties of the detector and material, including the Fano factor. A program of modelling was also undertaken and the work is presented in Chapter 3. Using the simulation, the mobility-lifetime products of the CZT material were determined to be ee = (3.9 0.15) x 10-3 cm2V-1 and hh = (1.2 0.2)x 10-5 cm2V-1. A dead-layer is hypothesized to lie beneath the electrodes of the CZT devices and the model was used to parameterize the depth of this region to 500-1000nm. Two-dimensional FITS arrays were also generated to describe the detector response to a range of input energies. Chapter 5 describes the manufacture and processing of CZT crystals. Spectroscopic crystals were successfully produced, including a novel device geometry. Finally, work intended to form the basis for pixel array development is presented in Chapter 6.
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Hoffmann, Agnes Irene Dorothee. "Analysis of hard X-ray emission from selected very high energy g-ray." Reutlingen, Bruno-Matzke-Str.15 A. Hoffmann, 2009. http://d-nb.info/999640429/34.
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Nilsson, Daniel. "Zone Plates for Hard X-Ray Free-Electron Lasers." Doctoral thesis, KTH, Biomedicinsk fysik och röntgenfysik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-122161.
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Hard x-ray free-electron lasers are novel sources of coherent x-rays with unprecedented brightness and very short pulses. The radiation from these sources enables a wide range of new experiments that were not possible with previous x-ray sources. Many of these experiments require the possibility to focus the intense x-ray beam onto small samples. This Thesis investigates the possibility to use diffractive zone plate optics to focus the radiation from hard x-ray free-electron lasers. The challenge for any optical element at free-electron laser sources is that the intensity in a single short pulses is high enough to potentially damage the optics. This is especially troublesome for zone plates, which are typically made of high Z elements that absorb a large part of the incident radiation. The first part of the Thesis is dedicated to simulations, where the temperature behavior of zone plates exposed to hard x-ray free-electron laser radiation is investigated. It is found that the temperature increase in a single pulse is several hundred Kelvin but still below the melting point of classical zone plate materials, such as gold, tungsten, and iridium. Even though the temperature increases are not high enough to melt a zone plate it is possible that stresses and strains caused by thermal expansion can damage the zone plate. This is first investigated in an experiment where tungsten gratings on diamond substrates are heated to high temperatures by a pulsed visible laser. It is found that the gratings are not damaged by the expected temperature fluctuations at free-electron lasers. Finally, a set of tungsten zone plates are tested at the Linac Coherent Light Source where they are exposed to a large number of pulses at varying fluence levels in a prefocused beam. Damage is only observed at fluence levels above those typically found in an unfocused x-ray free-electron laser beam. At higher fluences an alternative is to use a diamond zone plate, which has significantly less absorption and should be able to survive much higher fluence. Damage in diamond structures is investigated during the same experiment, but due to a remaining tungsten etch mask on top of the diamond the results are difficult to interpret. Additionally, we also demonstrate how the classical Ronchi test can be used to measure aberrations in focusing optics at an x-ray free-electron laser in a single pulse. The main result of this Thesis is that tungsten zone plates on diamond substrates can be used at hard x-ray free-electron laser sources.QC 20130514
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Bain, Hazel Miller. "Hard X-ray and radio studies of solar flares." Thesis, University of Glasgow, 2010. http://theses.gla.ac.uk/1751/.
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Combined X-ray and radio observations of the Sun provide powerful diagnostics of particle acceleration and transport effects during solar flares. In this thesis we present observations of two solar flares. In the first event we report what we believe to be the first observation of hard X-ray emission formed in a coronal, flare-related jet. Occurring on the 22nd of August 2002, the event was observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) and the Nobeyama Radioheliograph (NoRH) and Polarimeters (NoRP). During the impulsive phase RHESSI observed significant hard X-ray emission to energies as high as 30-50 keV in the jet. RHESSI spectroscopy shows a powerlaw spectrum with a spectral index of ~4 and NoRH images reveal radio emission at 17 GHz and 34 GHz co-spatial with the hard X-ray emission, thus supporting the evidence for nonthermal emission in the jet. The second event occurred on the 24th of August 2002 and was also observed by RHESSI and NoRH. The size and orientation of the flare, which occurred on the west limb of the Sun, make it particularly interesting to study. At both NoRH frequencies emission is observed at all points along a flare loop such that the looptop and footpoint emission are clearly separated. We present observations of the flare decay phase to investigate the long term evolution of the event. In particular we follow the evolution of relevant plasma parameters which are used as an input to a 3D gyrosynchrotron model in an attempt to reproduce the observed emission at radio wavelengths.
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Bird, Antony John. "A position-sensitive detector for hard X-ray astronomy." Thesis, University of Southampton, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292524.
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Zhang, Shuang Nan. "Instrumentation and data analysis for hard X-ray astronomy." Thesis, University of Southampton, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.252689.
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Leddon, Deborah L. "A Statistical Study of Hard X-Ray Solar Flares." Thesis, University of North Texas, 2001. https://digital.library.unt.edu/ark:/67531/metadc3045/.
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The results of a statistical study of hard x-ray solar flares are presented in this dissertation. Two methods of analysis were used, the Diffusion Entropy (DE) method coupled with an analysis of the data distributions and the Rescaled Range (R/S) Method, sometimes referred to as "Hurst's method". Chapter one provides an introduction to hard x-ray flares within the context of the solar environment and a summary of the statistical paradigms solar astronomers currently work under. Chapter two presents the theory behind the DE and R/S methods. Chapter three presents the results of the two analysis methodologies: most notably important evidence of the conflicting results of the R/S and DE methods, evidence of a Levy statistical signature for the underlying dynamics of the hard x-ray flaring process and a possible separate memory signature for the waiting times. In addition, the stationary and nonstationary characteristics of the waiting times and peak intensities, are revealed. Chapter four provides a concise summary and discussion of the results.
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Ahlberg, Erik, and Samin Hasan. "Optimising a small satellite for hard X-ray polarisation studies of gamma ray Bursts." Thesis, KTH, Fysik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-149677.
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Gamma ray bursts (GRBs) originate from extremely energetic extra-galactic events, and much is still unknown about them. Whereas the energy and time structure of GRBs have been studied extensively the past years, only a few polarisation measurements have been made on their initial, prompt emission. Determining the polarisation of GRBs will therefore provide a means to test proposed emission models. A small satellite (SPHiNX) has been proposed to measure the polarisation of X-rays from GRBs. The performance of the detector is optimised using Monte Carlo simulations of a typical GRB source, in order to produce a more efficient design. First, the effect on the performance when varying individual parameters is studied, and then when using several changes in conjunction for the optimisation. The new design improves the primary gure of merit, the minimum detectable polarisation (MDP), by 7% over the initial design, and improves the secondary gure of merit, the effective area, by 22%.Gammablixtar (GRBs) härrör från extremt energiska skeenden i andra galaxer, och ännu är mycket okänt kring dem. Emedan energi- och tidsstrukturen hos GRBs har studerats utförligt under senare år, har endast ett fåtal mätningar genomförts på polarisationen hos den initiella strålningen. Att fastställa hur polarisationen hos GRBs ser ut är därför ett sätt att testa föreslagna utstrålningsmodeller. En liten satellit (SPHiNX) har föreslagits för att mäta polarisationen i röntgenstrålar från GRBs. Detektorns prestanda opimeras genom att simulera GRB-strålning, så att en effektivare design kan tas fram. Först undersöks hur de individuella parametrarna påverkar prestandan, och sedan används sammantagna ändringar för att optimera utseendet. Den slutgiltiga designen förbättrar det primära godhetstalet, den minsta detekterbara polarisationen (MDP), med 7% jämfört med den ursprungliga designen, och förbättrar det sekundära godhetstalen, den effektiva arean, med 22%.
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Patommel, Jens. "Hard X-Ray Scanning Microscope Using Nanofocusing Parabolic Refractive Lenses." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-64982.
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Hard x rays come along with a variety of extraordinary properties which make them an excellent probe for investigation in science, technology and medicine. Their large attenuation length in matter opens up the possibility to use hard x-rays for non-destructive investigation of the inner structure of specimens. Medical radiography is one important example of exploiting this feature. Since their discovery by W. C. Röntgen in 1895, a large variety of x-ray analytical techniques have been developed and successfully applied, such as x-ray crystallography, reflectometry, fluorescence spectroscopy, x-ray absorption spectroscopy, small angle x-ray scattering, and many more. Each of those methods reveals information about certain physical properties, but usually, these properties are an average over the complete sample region illuminated by the x rays. In order to obtain the spatial distribution of those properties in inhomogeneous samples, scanning microscopy techniques have to be applied, screening the sample with a small x-ray beam. The spatial resolution is limited by the finite size of the beam. The availability of highly brilliant x-ray sources at third generation synchrotron radiation facilities together with the development of enhanced focusing x-ray optics made it possible to generate increasingly small high intense x-ray beams, pushing the spatial resolution down to the sub-100 nm range. During this thesis the prototype of a hard x-ray scanning microscope utilizing microstructured nanofocusing lenses was designed, built, and successfully tested. The nanofocusing x-ray lenses were developed by our research group of the Institute of Structural Physics at the Technische Universität Dresden. The prototype instrument was installed at the ESRF beamline ID 13. A wide range of experiments like fluorescence element mapping, fluorescence tomography, x-ray nano-diffraction, coherent x-ray diffraction imaging, and x-ray ptychography were performed as part of this thesis. The hard x-ray scanning microscope provides a stable x-ray beam with a full width at half maximum size of 50-100 nm near the focal plane. The nanoprobe was also used for characterization of nanofocusing lenses, crucial to further improve them. Based on the experiences with the prototype, an advanced version of a hard x-ray scanning microscope is under development and will be installed at the PETRA III beamline P06 dedicated as a user instrument for scanning microscopy. This document is organized as follows. A short introduction motivating the necessity for building a hard x-ray scanning microscope is followed by a brief review of the fundamentals of hard x-ray physics with an emphasis on free-space propagation and interaction with matter. After a discussion of the requirements on the x-ray source for the nanoprobe, the main features of synchrotron radiation from an undulator source are shown. The properties of the nanobeam generated by refractive x-ray lenses are treated as well as a two-stage focusing scheme for tailoring size, flux and the lateral coherence properties of the x-ray focus. The design and realization of the microscope setup is addressed, and a selection of experiments performed with the prototype version is presented, before this thesis is finished with a conclusion and an outlook on prospective plans for an improved microscope setup to be installed at PETRA IIIAufgrund ihrer hervorragenden Eigenschaften kommt harte Röntgenstrahlung in vielfältiger Weise in der Wissenschaft, Industrie und Medizin zum Einsatz. Vor allem die Fähigkeit, makroskopische Gegenstände zu durchdringen, eröffnet die Möglichkeit, im Innern ausgedehnter Objekte verborgene Strukturen zum Vorschein zu bringen, ohne den Gegenstand zerstören zu müssen. Eine Vielzahl röntgenanalytischer Verfahren wie zum Beispiel Kristallographie, Reflektometrie, Fluoreszenzspektroskopie, Absorptionsspektroskopie oder Kleinwinkelstreuung sind entwickelt und erfolgreich angewendet worden. Jede dieser Methoden liefert gewisse strukturelle, chemische oder physikalische Eigenschaften der Probe zutage, allerdings gemittelt über den von der Röntgenstrahlung beleuchteten Bereich. Um eine ortsaufgelöste Verteilung der durch die Röntgenanalyse gewonnenen Information zu erhalten, bedarf es eines sogenannten Mikrostrahls, durch den die Probe lokal abgetastet werden kann. Die dadurch erreichbare räumliche Auflösung ist durch die Größe des Mikrostrahls begrenzt. Aufgrund der Verfügbarkeit hinreichend brillanter Röntgenquellen in Form von Undulatoren an Synchrotronstrahlungseinrichtungen und des Vorhandenseins verbesserter Röntgenoptiken ist es in den vergangen Jahren gelungen, immer kleinere intensive Röntgenfokusse zu erzeugen und somit das räumliche Auflösungsvermögen der Röntgenrastermikroskope auf unter 100 nm zu verbessern. Gegenstand dieser Arbeit ist der Prototyp eines Rastersondenmikroskops für harte Röntgenstrahlung unter Verwendung refraktiver nanofokussierender Röntgenlinsen, die von unserer Arbeitsgruppe am Institut für Strukturphysik entwickelt und hergestellt werden. Das Rastersondenmikroskop wurde im Rahmen dieser Promotion in Dresden konzipiert und gebaut sowie am Strahlrohr ID 13 des ESRF installiert und erfolgreich getestet. Das Gerät stellt einen hochintensiven Röntgenfokus der Größe 50-100 nm zur Verfügung, mit dem im Verlaufe dieser Doktorarbeit zahlreiche Experimente wie Fluoreszenztomographie, Röntgennanobeugung, Abbildung mittels kohärenter Röntgenbeugung sowie Röntgenptychographie erfolgreich durchgeführt wurden. Das Rastermikroskop dient unter anderem auch dem Charakterisieren der nanofokussierenden Linsen, wobei die dadurch gewonnenen Erkenntnisse in die Herstellung verbesserten Linsen einfließen. Diese Arbeit ist wie folgt strukturiert. Ein kurzes einleitendes Kapitel dient als Motivation für den Bau eines Rastersondenmikroskops für harte Röntgenstrahlung. Es folgt eine Einführung in die Grundlagen der Röntgenphysik mit Hauptaugenmerk auf die Ausbreitung von Röntgenstrahlung im Raum und die Wechselwirkungsmechanismen von Röntgenstrahlung mit Materie. Anschließend werden die Anforderungen an die Röntgenquelle besprochen und die Vorzüge eines Undulators herausgestellt. Wichtige Eigenschaften eines mittels refraktiver Röntgenlinsen erzeugten Röntgenfokus werden behandelt, und das Konzept einer Vorfokussierung zur gezielten Anpassung der transversalen Kohärenzeigenschaften an die Erfordernisse des Experiments wird besprochen. Das Design und die technische Realisierung des Rastermikroskops werden ebenso dargestellt wie eine Auswahl erfolgreicher Experimente, die am Gerät vollzogen wurden. Die Arbeit endet mit einem Ausblick, der mögliche Weiterentwicklungen in Aussicht stellt, unter anderem den Aufbau eines verbesserten Rastermikroskops am PETRA III-Strahlrohr P06
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Uhlén, Fredrik. "Nanofabrication of Zone Plates for Hard X-Ray Free-Electron Lasers." Doctoral thesis, KTH, Biomedicinsk fysik och röntgenfysik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-158121.
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This Thesis describes the development of hard X-ray zone plates intended for focusing radiation at X-ray free-electron lasers (XFELs). XFELs provide unprecedented brightness and zone plates which are put in the intense X-ray beam are at risk of being damaged. Therefore, it is crucial to perform damage tests in order to design zone plates which can survive the XFEL beam. Zone plates are diffractive nanofocusing optics and are regularly used at high brightness synchrotron beamlines in the soft and hard X-ray regime. The resolution of a zone plate is proportional to its outermost zonewidth and thus depends on the smallest feature that can be fabricated. State-of-the-art nanofabrication processes developed for zone plates are able to produce zonewidths down to 10 nm. However, for hard X-rays, the zone plates need to be of sufficient thickness to efficiently focus the radiation. Thus, the limit in the fabrication of hard X-ray zone plates lies in the high aspect-ratios. This Thesis describes two processes developed for high aspect-ratio nanostructuring. The first process uses tungsten as diffractive material. Aspect-ratios up to 1:15 have been accomplished. Furthermore, a mounting method of a central stop directly on the zone plate is also presented. The other fabrication process uses diamond, in which aspect-ratios of 1:30 have been demonstrated. Both processes rely on thin-film deposition techniques, electron-beam lithography, and reactive ion etching. Thanks to the materials’ excellent thermal properties these types of zone plates should be suitable for XFEL applications. Tungsten and diamond diffractive optics have been tested at an XFEL at Stanford (LCLS), and damage investigations were performed in order to determine the maximum fluence that could be imposed on the optics before degradation occured. The conclusion of these damage tests is that tungsten and diamond diffractive optics can survive the XFEL beam and could potentially be used in beamline experiments relying on nanofocused X-ray beams. Finally in this Thesis, characterization of two zone plates using an interferometer is presented, where it is also shown that the interferometric method can be used to pin-point beamline instabilities.QC 20150112
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Müller, Oliver [Verfasser]. "Hard X-ray Synchrotron Beamline Instrumentation for Millisecond Quick Extended X-ray Absorption Spectroscopy / Oliver Müller." Wuppertal : Universitätsbibliothek Wuppertal, 2016. http://d-nb.info/1120339022/34.
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Haydock, Esther. "Electron beam wave relaxation and solar flare hard X-ray emission." Thesis, University of Glasgow, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269508.
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Mudie, Stephen. "Characterisation of Group III nitrides using hard X-ray synchrotron radiation." Monash University, School of Physics and Materials Engineering, 2004. http://arrow.monash.edu.au/hdl/1959.1/9729.
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Alexander, Robert Calum. "Influence of photospheric back-scatter on flare hard x-ray diagnostics." Thesis, University of Glasgow, 2010. http://theses.gla.ac.uk/1707/.
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In this thesis I present the results of studies on the influence of solar photospheric back–scatter on Hard X–Ray (HXR) flare diagnostics. Specifically the thesis presented is concerned with the effect of back–scatter photons upon the morphology of the Hard X–Ray photon spectrum and its effect on the inferred parent electron spectrum. I present a theoretical investigation into Compton reflected HXR photons, known as the photospheric Albedo, and explore the effect of photospheric albedo on observations of global flare hard X-ray spectra for isotropic emission. I examine, for the Kramers cross-section, the consequences of ignoring the albedo correction in using observed spectra to infer flare source electron spectra for thin and thick target interpretations and show that the effects are very significant in terms of inferred spectral shape, especially for hard spectra. I extend this investigation to consider the effect of the photospheric albedo on observations of global flare hard X-ray spectra for anisotropic primary photon emission by examining, for the Kramers cross-section, the consequences of ignoring the albedo correction in using observed spectra to infer flare source electron spectra for thin and thick target interpretations. For an energy dependent multiplier α I find that the results for anisotropic emission are similar in shape to isotropic emission when I assume a linear model for the anisotropy. I then explore two complementary techniques for determining the Compton back-scattered component of the observed photon spectrum using a model independent Greens function approach. The first is a matrix based technique developed by Kontar & Brown (2006) which I extend to include anisotropic primary photon emission using an Eddington hemispheric approach along with an empirical fit to published data. The second is a full radiative transfer Greens function approach developed by Poutanen et al. (1996) which I also extend to include anisotropic primary photon emission again using an empirical fit to published data. In both cases I investigate how anisotropic primary photon emission effects the observed photon spectrum by studying the differences in the size and shape of the albedo. In the final chapter I use the results from the anisotropic Eddington hemispheric Greens function approach and the anisotropic full radiative transfer Greens function approach to investigate the findings published in Kontar & Brown (2006) using the Stereoscopic electron spectroscopy technique. I conclude from the results of this comparison that doing a full anisotropic scattering properly does not fundamentally change the findings of Kontar and Brown which are specifically that the electron distribution is nearly isotropic to such a degree of confidence that it casts doubt on models which are based upon beaming such as the collisional thick target (Brown 1971).
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Kole, Merlin. "Background Studies for the Balloon-Borne Hard X-ray Polarimeter PoGOLite." Doctoral thesis, KTH, Partikel- och astropartikelfysik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-155754.
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The polarisation degree and angle of the X-ray flux emitted by astrophysical objects holds valuable information on the responsible emission mechanisms and on the emission environments. PoGOLite is a balloon-borne hard X-ray polarimeter designed to measure polarisation using a segmented plastic scintillator array. The instrument was launched for its first scientific, near-circumpolar, flight in July 2013 from the Esrange Space Centre in Northern Sweden. The primary observation target for this flight, the Crab, was observed during the first 2 days of flight. One of the main challenges for PoGOLite is the relatively high measurement background, predicted to be induced by atmospheric neutrons. No measurement data on the neutron environment for the flight conditions of PoGOLite is however available, making exact predictions impossible. This environment was therefore studied in detail. A Monte Carlo based model of the atmospheric neutron flux was developed. This model is capable of providing differential neutron energy spectra for all altitudes, latitudes and solar activities. The predictions of this model were found to be in good agreement both with measurement data, measured by high altitude aircraft, and with predictions by location and time specific models. The results from the model were verified with data recorded by a purpose-build balloon-borne neutron detector, PoGOLino. The PoGOLino instrument uses novel neutron sensitive LiCAF scintillators sandwiched between BGO crystals which serve as an anti-coincidence system. PoGOLino was launched from the Esrange Space Centre to an altitude of 31 km on March 20th 2013 and performed the first successful measurements of the neutron flux for the PoGOLite flight conditions. Using the developed model the background as measured by the PoGOLite mission in 2013 was studied. Monte Carlo simulations were used to confirm that the PoGOLite background during flight is dominated by neutrons. The simulated neutron induced signal rate and its variations with time were furthermore found to be in good agreement with measurements. Based on these results the implications of the background on the polarisation measurements of the Crab were studied. Lastly, based on the acquired knowledge of the background, changes to the instrument geometry for potential future flight of PoGOLite were studied along with the expected achievable improvement in performance for such flights.QC 20141113
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Grätz, Matthias. "Characterisation and application of a laser-based hard X-ray source." Lund : Lund Institute of Technology, 1998. http://catalog.hathitrust.org/api/volumes/oclc/68945036.html.
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Ivan, Adrian 1964. "Fabrication and characterization of multilayers for focusing hard x-ray optics." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/30006.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 2002.Includes bibliographical references.
This study investigated the growth of multilayers with depth-graded thicknesses and their performance as x- ray mirrors for the next generation of focusing telescopes. Different material combinations were studied for the first time employing a consistent methodology for the DC magnetron sputtering growth of the multilayers and their characterization by x-ray reflectivity (XRR) measurements. The width of the interfaces was identified as the most important factor that must be controlled and minimized to achieve high reflectivity. The optimization of the process parameters led to interface widths ([sigma]) of 3.0-4.5 [angstroms] for both W/Si and Pt/C, the most interesting materials for this application. The other material combinations studied were: W/C, Mo/Si, Ni/C, Ni-V/C, WSi₂/Si, and Nb/Si. The interface widths for W/C were about 4 [angstroms], but wider ([sigma] [greater than or equal to] 7 [angstroms]) for Mo/Si and Ni/C. The analysis indicated that the large Mo/Si interface width was due to the formation of a silicide compound. In the case of Ni/C, TEM and XRR measurements concurred to an island growth mode of nickel for thicknesses less than 17 [angstroms], resulting in a high roughness at the C-on-Ni interface. A trial with WSi₂/Si multilayers showed values of sigma comparable to the simpler W/Si system. For Nb/Si the interface widths were larger than 9 [angstroms]. Depth graded W/Si, Pt/C, and W/C multilayers were deposited on flat substrates in process conditions optimized for low [sigma] (3-5 [angstroms]). Their x-ray reflectivity was measured at high energy using synchrotron radiation sources and confirmed the designs for the structure of the multilayers and the reflection bandpass.
(cont.) The reflectivity was between 20 and 40 % for grazing incidence angles used in hard x-ray focusing telescopes. One of the deposition chambers built for this study has the unique capability to coat with multilayers the inside of integral conical shells that compose the telescope mirror system. We have accomplished for the first time this type of coatings and present results from their x-ray measurements.
by Adrian Ivan.
Ph.D.
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Zborowski, Charlotte. "Characterization of deeply buried interfaces by Hard X-ray Photoelectron Spectroscopy." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEC025/document.
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Cette thèse vise à améliorer la méthode d'analyse du fond continu inélastique afin de l'appliquer à des cas qui présentent un intérêt technologique. En effet, ces améliorations sont cruciales car elles portent sur des critères de précision et de gain de temps, plus particulièrement pour l’étude de dispositifs présentant plusieurs couches profondément enterrées de matériaux bien distincts. Ainsi, l'analyse du fond continu inélastique associée à la spectroscopie de photoélectrons à rayons X durs (HAXPES) présente un grand intérêt car l’HAXPES permet de sonder plus profondément dans un échantillon qu'avec la spectroscopie de photoélectrons à rayons X classique (XPS). Ce présent travail porte sur des échantillons technologiquement pertinents, principalement des transistors à haute mobilité d'électrons (HEMTs), à certaines étapes cruciales de leur processus de fabrication, tels que des recuits. Il est donc très important que ces analyses soient effectuées de manière non destructive afin de préserver les interfaces enterrées. Ce sont souvent l'emplacement de phénomènes complexes qui sont critiques pour les performances du dispositif et une meilleure compréhension est une condition préalable à l’amélioration des dispositifs. Dans ce travail, les phénomènes de diffusion en profondeur sont étudiés grâce à l’analyse du fond continu inélastique associée à l’HAXPES (en utilisant le logiciel QUASES) pour des profondeurs allant jusqu'à 60 nm. Les résultats de distribution en profondeur présentent des écarts par rapport aux mesures TEM inférieures à 5%. Le choix des paramètres d'entrée de la méthode est discuté pour une large gamme d'échantillons et des règles simples en sont issues qui rendent l'analyse réelle plus facile et plus rapide à effectuer. Enfin, il a été montré que la spectromicroscopie faite avec la technique HAXPEEM peut fournir des spectres à chaque pixel utilisables pour l’analyse du fond continu inélastique. Cela peut fournir une cartographie 3D de la distribution en profondeur des éléments de manière non-destructiveThis thesis aims at improving the inelastic background analysis method in order to apply it to technologically relevant samples. Actually, these improvements are utterly needed as they concern criteria of accuracy and time saving particularly for analysis of devices presenting deeply buried layers with different materials. For this purpose, the interest of the inelastic background analysis method is at its best when combined with hard X-ray photoelectron spectroscopy (HAXPES) because HAXPES allows to probe deeper in the sample than with conventional X-ray photoelectron spectroscopy (XPS). The present work deals with technologically relevant samples, mainly the high-electron mobility transistor (HEMT), at some crucial steps of their fabrication process as annealing. Actually, it is very important that these analyses shall be performed non-destructively in order to preserve the buried interfaces. These are often the location of complex phenomena that are critical for device performances and a better understanding is often a prerequisite for any improvement. In this thesis, the in-depth diffusion phenomena are studied with the inelastic background analysis technique (using the QUASES software) combined with HAXPES for depth up to 60 nm. The depth distribution results are determined with deviations from TEM measurements smaller than a typical value of 5%. The choice of the input parameters of the method is discussed over a large range of samples and simple rules are derived which make the actual analysis easier and faster to perform. Finally, it was shown that spectromicroscopy obtained with the HAXPEEM technique can provide spectra at each pixel usable for inelastic background analysis. This is a proof of principle that it can provide a 3D mapping of the elemental depth distribution with a nondestructive method
Denne afhandling har til formål at forbedre den uelastiske baggrundsanalysemetode til anvendelser i den til teknologiske industri. Faktisk er disse forbedringer absolut nødvendige, for at opnå nøjagtighed og tidsbesparelse, især for analyse af prøver med dybt begravede lag af forskellige materialer. Til det formål er interessen for den uelastiske baggrundsanalysemetode bedst i kombination med hård røntgenfotoelektron-spektroskopi (HAXPES), fordi HAXPES gør det muligt at probe dybere i prøven end med konventionel røntgenfotoelektron-spektroskopi (XPS). Dette arbejde beskæftiger sig med teknologisk relevante prøver, hovedsagelig høj-elektron mobilitetstransistor (HEMT), på nogle afgørende trin i deres fremstillingsproces som fx annealing. Faktisk er det meget vigtigt, at disse analyser udføres på en ikke-destruktiv måde for at bevare de begravede grænseflader. Det er ofte her de komplekse fysiske fænomener opstår, som er kritiske for fuktionaliteten, og en bedre forståelse af grænsefladerne er ofte en forudsætning for at kunne forbedre denne. I denne afhandling studeres de dybdegående diffusionsfænomener med den uelastiske baggrundsanalyse teknik (ved hjælp af QUASES software) kombineret med HAXPES for dybder op til 60 nm. Dybdestributionsresultaterne har afvigelser fra TEM-målinger mindre end en typisk værdi på 5%. Valget af input parametre for metoden er diskuteret på bagground af et stort udvalg af prøver samt omfattende simuleringer og enkle regler er udledt, hvilket gør den praktiske analyse nemmere og hurtigere at udføre. Endelig blev det vist, at spektromikroskopi opnået med HAXPEEM-teknikken kan tilvejebringe spektre ved hver enkelt pixel som kan anvendes til uelastisk baggrundsanalyse. Dette viser at i princippet kan en 3D-billeddannelse af den elementære dybdefordeling bestemmes ikke destruktivt
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Fioretti, Valentina <1982>. "Background minimization issues for next generation hard X-ray focusing telescopes." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3858/.
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The hard X-ray band (10 - 100 keV) has been only observed so far by collimated and coded aperture mask instruments, with a sensitivity and an angular resolution lower than two orders of magnitude as respects the current X-ray focusing telescopes operating below 10 - 15 keV.
The technological advance in X-ray mirrors and detection systems is now able to extend the X-ray focusing technique to the hard X-ray domain, filling the gap in terms of observational performances and providing a totally new deep view on some of the most energetic phenomena of the Universe.
In order to reach a sensitivity of 1 muCrab in the 10 - 40 keV energy range, a great care in the background minimization is required, a common issue for all the hard X-ray focusing telescopes.
In the present PhD thesis, a comprehensive analysis of the space radiation environment, the payload design and the resulting prompt X-ray background level is presented, with the aim of driving the feasibility study of the shielding system and assessing the scientific requirements of the future hard X-ray missions.
A Geant4 based multi-mission background simulator, BoGEMMS, is developed to be applied to any high energy mission for which the shielding and instruments performances are required. It allows to interactively create a virtual model of the telescope and expose it to the space radiation environment, tracking the particles along their path and filtering the simulated background counts as a real observation in space.
Its flexibility is exploited to evaluate the background spectra of the Simbol-X and NHXM mission, as well as the soft proton scattering by the X-ray optics and the selection of the best shielding configuration.
Altough the Simbol-X and NHXM missions are the case studies of the background analysis, the obtained results can be generalized to any future hard X-ray telescope. For this reason, a simplified, ideal payload model is also used to select the major sources of background in LEO.
All the results are original contributions to the assessment studies of the cited missions, as part of the background groups activities.
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Langer, Max. "Phase retrieval in the Fresnel region for hard X-ray tomography." Lyon, INSA, 2008. http://theses.insa-lyon.fr/publication/2008ISAL0094/these.pdf.
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The aim of this work was to extend the validity of phase retrieval from Fresnel diffraction patterns to strongly absorbing objects. To this effect, new linear contrast model is presented. It is valid for slowly varying objects and unifies the transport of intensity equation and contrast transfer function in that it approaches each in the limit of small propagation distance and weak absorption respectively. We go on to notice that, due to how the phase information is propagated to the recorded images, the phase retrieval is sensitive to noise in the low-frequency range and is actually singular at zero frequency. We propose two regularization schemes, one based on regularization in the Fourier and wavelet domains, and one based on the assumption that the imaged object has homogeneous composition. For the latter, we also develop an algorithm for automatic regularization parameter selection. The algorithm based on the homogeneous composition assumption proves to be useful for a wide range of samples. As examples, three applications are presented. The application of the algorithm to the imaging of a fossil allowed the discovery of the first fossilized brain found. In paleontology, the samples often show a high degree of homogeneity. The algorithm was also applied to the imaging of artificial bone scaffolds grown in vitro with bone cells, for use in tissue engineering. It allows quantitative analysis of scaffold composition and more importantly, 3D analysis of an uncalcified matrix deposited by the cells. Finally, the algorithm is applied to small animal imaging. The imaging of a blackbird embryo is shown, where it allows the segmentation of both bone and soft tissue. Finally, future directions of phase retrieval in the Fresnel region are considered. No general algorithm exists yet. The possibility of further development of linearized algorithms is discussed. Non-linear algorithms, namely the iterative algorithms used in Fraunhofer phase retrieval, are also considered. Three variants are adapted to the Fresnel case, with several recorded images, and are applied to simulated data. It is concluded that application of this class of algorithms to the Fresnel diffraction case is not trivial and that they are not suitable in their present formLe but de cette étude était d'étendre la validité de la reconstruction de phase dans la région de Fresnel au cas d'objet très absorbant. Nous présentons ici un nouveau modèle linéaire de contraste. Ce modèle est valide pour les objets présentant peu de contraste de densité et regroupe les modèles TIE et CTF du fait qu'il approche chacune des limites de ces modèles, à savoir les courtes distances de propagations et les objets peu absorbants. C'est pourquoi nous l'appelons l'approche mixte. La TIE, la CFT et l'approche mixte, ainsi que l'application de la TIE au cas des faibles absorptions ont étés évalué en utilisant à la fois des données simulées et expérimentales. Ces différentes comparaisons ont montrées que dans la pratique, l'approche mixte donnait les meilleurs résultats, d'après les critères d'évaluation choisit. Il a été noté que, étant donné la façon dont la phase est propagé jusqu'aux images enregistrées, la reconstruction de phase est sensible au bruit dans la gamme des basses fréquences et qu'elle est singulière à fréquence 0. Pour cela, nous proposons deux schémas de régularisations, un basé sur la régularisation dans les domaines de Fourriers et des ondelettes, et un second basé sur une hypothèse de composition homogène pour l'objet imagé. Pour ce dernier, nous avons aussi développé un algorithme de sélection automatique des paramètres de régularisation. L'algorithme basé sur l'hypothèse de composition homogène se révéla être utile dans une gamme très variée d'échantillon. Son application à l'imagerie de fossile inclus dans la roche permis la découverte du premier cerveau de poisson fossilisé. En paléontologie, les échantillons montrent souvent un grand degré d'homogénéité. Cet algorithme fut aussi appliqué à l'imagerie de biomatériaux cultivés in vitro avec des cellules osseuses, pour utilisation dans ingénierie tissulaire. Cela permit l'analyse quantitative de la composition de l'échafaudage et plus important, l'analyse 3D d'une matrice non-calcifié déposée par les cellules. Enfin, les perspectives pour la reconstruction de la phase dans la région de Fresnel sont présentées. Pour le moment, il n'existe aucun algorithme général. La possibilité de développement d'autres algorithmes linéarisés est brièvement abordée. Des algorithmes non-linéaires, à savoir les algorithmes itératifs utilisés dans la reconstruction de phase pour le phénomène de diffraction de Fraunhofer, sont aussi considérés. Trois variantes de cet algorithme sont adaptées au cas de la diffraction de Fresnel, avec plusieurs images enregistrées à différences de propagation, et sont appliqués à des données simulées. Leur adaptation à la diffraction de Fresnel pour le cas des courtes distances de propagation avec plusieurs images n'est pas triviale. Bien que trois schémas numériques aient été proposés et testés sur des données simulées, nous concluons qu'ils ne conviennent pas. .
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Cederström, Björn. "A multi-prism lens for hard X-Rays." Doctoral thesis, KTH, Fysik, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3423.
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This thesis describes a new type of refractive lens for hardx-rays. It is shown that a linear array of prisms, slightlyinclined with respect to the optical axis, will form a linefocus at a certain distance from the lens. Hence, the namemulti-prism lens. These lenses are free from sphericalaberration and are similar to planar parabolic compoundrefractive lenses in terms of performance. However, theydistinguish themselves in that only planar surfaces need to befabricated. A special feature is that the focal length can beeasily varied by adjusting the inclination angle. Theoretical calculations, based on geometrical and physicaloptics, are used to characterize the lenses. Aberrations arediscussed, as well as the sensitivity to fabricationimperfections, and insufficient flatness is identified as apotential problem. Ray-tracing is used to test theapproximations and assumptions used in the theory. Applicationsin x-ray microscopy and mammography are discussed. Lenses have been made of beryllium, silicon, epoxy anddiamond using different methods. Results from measurements ofsurface roughness and figure error show that the imperfectionsof the silicon and epoxy lenses should have a small impact,while the beryllium lenses should suffer from strongscattering. Experiments were performed at the EuropeanSynchrotron Radiation Facility and sub-µm focal linewidths, close to theoretical expectations, were measured forsilicon and epoxy lenses at 30 keV and 14 keV, respectively.Insertion gains up to 40 were reached. Two crossed lenses wereused to obtain focusing in two dimensions and a point focus.The smallest measured focal spot size was 1.0 µm by 5 .4µm, and an insertion gain exceeding 100 was achieved usingepoxy lenses. The diamond lenses suffered from voids in the materialformed in the chemical vapor deposition process, butnevertheless provided focal lines less than 2 µm in width,albeit at at relatively low insertion gain of 13. Due to theirexcellent thermal properties, these lenses are put forward ascandidates for optics at the next generationultra-high-intensity synchrotron beams and x-ray free electronlasers. Keywords:x-ray, optics, refractive, lens, mammography,synchrotron.QC 20100524
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Damauskaitė, Jovita. "Research And Application Of Hard Cosmic Ray Flux For Forecasting Meteorological Conditions." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20101222_130615-72153.
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The thesis investigates cosmic rays and their scattering in the atmosphere and the change in their intensity caused by the frequency of meteorological phenomenon. The main objective of the research is the change in cosmic rays as well as atmospheric pressure and estimation of their connection. A thorough analysis and interpretation allow to supplement meteorological information for weather forecasts.Disertacijoje nagrinėjama kosminė spinduliuotė ir jos sklaida atmosferoje bei jos intensyvumo kaita, kurią lemią meteorologinių reiškinių dažnumas. Pagrindinis tyrimo objektas yra kietosios kosminės spinduliuotės ir atmosferos slėgio pokyčiai bei jų sąryšio įvertinimas. Kosminės spinduliuotės duomenų detali analizė ir interpretacija leidžia papildyti meteorologinę informaciją orų prognozei.
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Lyu, Chunhai [Verfasser], and Christoph H. [Akademischer Betreuer] Keitel. "Narrow-band hard-x-ray lasing / Chunhai Lyu ; Betreuer: Christoph H. Keitel." Heidelberg : Universitätsbibliothek Heidelberg, 2018. http://d-nb.info/1177252597/34.
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Lingham, Manohar. "Plasma-assisted sputter deposition of multilayer mirrors for hard X-ray synchrotron." Thesis, University of London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298365.
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Chakrabarty, Deepto Prince Thomas A. Prince Thomas A. "Hard X-ray detection and timing of accretion-powered pulsars with BATSE /." Diss., Pasadena, Calif. : California Institute of Technology, 1996. http://resolver.caltech.edu/CaltechETD:etd-09022008-132322.
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Carstairs, Ian Ruthven. "Kernel density estimators applied to hard X-ray observations of the Crab Pulsar." Thesis, University of Southampton, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315292.
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Brocksopp, Catherine. "Multiwavelength variability of black hole x-ray binaries in the low/hard state." Thesis, [n.p.], 2000. http://oro.open.ac.uk/19112/.
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Stampanoni, Marco. "A novel approach towards hard X-ray submicrometer computer tomography with synchrotron radiation." [S.l. : s.n.], 2002. http://e-collection.ethbib.ethz.ch/ecol-pool/diss/fulltext/eth14884.pdf.
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Chen, Chi Ming Hubert Harrison Fiona A. "Development of hard X-ray imaging detectors for the High Energy Focusing Telescope /." Diss., Pasadena, Calif. : California Institute of Technology, 2008. http://resolver.caltech.edu/CaltechETD:etd-04202008-135222.
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Scaringi, Simone. "Machine learning from hard X-ray surveys : applications to magnetic cataclysmic variable studies." Thesis, University of Southampton, 2009. https://eprints.soton.ac.uk/161197/.
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Within this thesis are discussed two main topics of contemporary astrophysics. The first is that of machine learning algorithms for astronomy whilst the second is that of magnetic cataclysmic variables (mCVs). To begin, an overview is given of ISINA: INTEGRAL Scouce Identifiction Network Algorithm. This machine learning algorithm, using random forests, is applied to the IBIS/ISGRI data set in order to ease the production of unbiased future soft gamma-ray source catalogues. The feature extraction process on an initial candidate list is described together with feature merging. Three trainng and testing sets are created in order to deal with the diverse time-scales encountered when dealing with the gamma-ray sky: one dealing with faint persistent source recognition, one dealing with strong persistent sources and a final one dealing with transients. For the latter, a new transient detection technique is introduced and described: the transient matrix. Finally the performance of the network is assessed and discussed using the testing set and some illustrative source examples. ISINA is also compared to the more conventional approach of visual inspection. Next mCVs are discussed, and in particular the properties arising from a hard X-ray selected sample which has proven remarkably efficient in detecting intermediate polars and asynchronous polars, two of the rarest type of cataclysmic variables (CVs). This thesis focuses particularly on the link between hard X-ray properties and spin/orbital periods. To this end, a new sample of these objects is constructed by cross-corelating candidate sources detected in INTEGRAL/IBIS observations against catalogues of known CVs. Also included in the analysis are hard X-ray Observations from Swift/BAT and SUZAKU/HXD in order to make the study more complete. It is found that most hard X-ray detected mCVs have Pspin/Porb<0.1 above the period gap. In this respect, attention is given to the very low number of detected systems in any ban between Pspin/Porb = 0.3 and Pspin/Porb = 1 and the apparent peak of the Pspin/Porb distribution at about 0.1. The observational features of the Pspin - Porb plane are discussed in the context of mCV evolution scenarios. Also presented is evidence for correlations between hard X-ray spectral hardness and Pspin, Porb and Pspin/Porb. An attempt to explain the observed correlations is made in th context of mCV evolution and accretion footpring geometrirs on the whit dwarf surface.
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Tsuboi, Yoko. "Hard X-ray Probing of Dark Clouds : Protostar Structure and the Magnetic Activities." 京都大学 (Kyoto University), 1999. http://hdl.handle.net/2433/181945.
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Almqvist, Heléne. "Studies on root hard-tissue demineralization and remineralization measured by ¹²⁵I absorptiometry." Stockholm : Karolinska Institutet, 1993. http://catalog.hathitrust.org/api/volumes/oclc/29572338.html.
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Jeanjean, Sébastien. "Vers l' optimisation du rayonnement d' un haut-parleur dans un habitacle automobile : résolution des problèmes de modélisation." Paris 6, 2005. http://www.theses.fr/2005PA066314.
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Baumgartner, Wayne. "Elemental abundances via X-ray observations of galaxy clusters and the InFOC[mu]S [i.e. InFOCuS] hard X-ray telescope." College Park, Md. : University of Maryland, 2004. http://hdl.handle.net/1903/1387.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2004.InFOCuS on t.p. of PDF has the Greek letter for MU instead of u. Thesis research directed by: Astronomy. InFOCuS in PDF has the Greek letter for mu instead of u. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Hoffmann, Agnes Irene Dorothee [Verfasser]. "Analysis of hard X-ray emission from selected very high energy γ-ray [gamma-ray] sources observed with INTEGRAL / vorgelegt von Agnes Irene Dorothee Hoffmann." Reutlingen, Bruno-Matzke-Str.15 : A. Hoffmann, 2009. http://d-nb.info/999640429/34.
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Geck, Jochen. "Spins, charges, and orbitals in perovskite manganites : resonant and hard x-ray scattering studies /." Berlin : Mensch & Buch Verl, 2004. http://www.loc.gov/catdir/toc/fy0804/2007464041.html.
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Ion, Valentina. "Nonlinear approaches for phase retrieval in the Fresnel region for hard X-ray imaging." Phd thesis, INSA de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-01015814.
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The development of highly coherent X-ray sources offers new possibilities to image biological structures at different scales exploiting the refraction of X-rays. The coherence properties of the third-generation synchrotron radiation sources enables efficient implementations of phase contrast techniques. One of the first measurements of the intensity variations due to phase contrast has been reported in 1995 at the European Synchrotron Radiation Facility (ESRF). Phase imaging coupled to tomography acquisition allows threedimensional imaging with an increased sensitivity compared to absorption CT. This technique is particularly attractive to image samples with low absorption constituents. Phase contrast has many applications, ranging from material science, paleontology, bone research to medicine and biology. Several methods to achieve X-ray phase contrast have been proposed during the last years. In propagation based phase contrast, the measurements are made at different sample-to-detector distances. While the intensity data can be acquired and recorded, the phase information of the signal has to be "retrieved" from the modulus data only. Phase retrieval is thus an illposed nonlinear problem and regularization techniques including a priori knowledge are necessary to obtain stable solutions. Several phase recovery methods have been developed in recent years. These approaches generally formulate the phase retrieval problem as a linear one. Nonlinear treatments have not been much investigated. The main purpose of this work was to propose and evaluate new algorithms, in particularly taking into account the nonlinearity of the direct problem. In the first part of this work, we present a Landweber type nonlinear iterative scheme to solve the propagation based phase retrieval problem. This approach uses the analytic expression of the Fréchet derivative of the phase-intensity relationship and of its adjoint, which are presented in detail. We also study the effect of projection operators on the convergence properties of the method. In the second part of this thesis, we investigate the resolution of the linear inverse problem with an iterative thresholding algorithm in wavelet coordinates. In the following, the two former algorithms are combined and compared with another nonlinear approach based on sparsity regularization and a fixed point algorithm. The performance of theses algorithms are evaluated on simulated data for different noise levels. Finally the algorithms were adapted to process real data sets obtained in phase CT at the ESRF at Grenoble.