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Calibration and commissioning results of the NUCLEUS experiment
Get PDFNeutrinos, despite outnumbering every other particle in the entire universe, have eluded discovery for more than 25 years after being postulated and still pose a challenge both to theorists and experimentalists.
There are diverse neutrino-matter interactions which span a broad range of energies, with a common denominator: the smallness of the cross-section. For MeV neutrinos, this cross-section is below and makes the observation of these particles in laboratory experiments extremely challenging, as years of dedicated neutrino oscillation experiments have demonstrated. One notable exception to this rule is the \cevns[.] This weak neutral current interaction stands out by having a large, by neutrino standards, Standard Model cross-section, which is more than 2 orders of magnitude higher than other neutrino processes. This is a game changer in the experimental landscape, as it allows the study of neutrinos using relatively small detectors (with masses ranging from 10~g to 1~kg), as opposed to ton or multitone experiments such as Borexino or Juno. On the other hand, the only \cevns observable is the energy of the induced nuclear recoil, which is at the 100~eV scale, meaning that this process is renown to be difficult to measure because detectors with an energy threshold as low as O(10~eV) are needed.
Among the many physics motivations to study \cevns[,] a precision measurement of its cross-section would provide the means to unveil new physics beyond the Standard Model, like non-standard interactions or an unforeseen scaling of the weak mixing angle. Moreover, the detector miniaturization, allowed by the high cross-section, will give rise to new branches of neutrino applications for both civilian and military purposes.
This thesis develops in the context of the NUCLEUS experiment, which aims to detect \cevns using the high anti-neutrino flux from the two 4.25~GW reactors cores of the Chooz-B nuclear power plant in France. NUCLEUS will exploit an innovative detection system that consists of a 10~g array of cubic CaWO and AlO crystals as target detectors. The energy deposited in the crystals is read with superconductive \acl{TES}s deposited on the material surface. This technique allowed the NUCLEUS collaboration to develop detectors that reach the low energy thresholds required for a successful \cevns observation.
At the start of this Ph.D. research, the NUCLEUS experiment was in its preliminary stage and only the basic setup for detector development was present. Over recent years, substantial improvements have been made to both the experimental setup and data analysis.
A crucial issue facing cryogenic calorimeters, designed to measure energy depositions as low as O(10~eV), is the characterization of their response. To tackle this, NUCLEUS adopted a novel calibration technique based on the use of optical photons shining on the target calorimeter. The LANTERN project was developed in the context of this work to provide a highly scalable and cost-effective hardware setup to perform this calibration. LANTERN proved to be an elegant and simple solution that can be employed to achieve a full characterization of the detector response, both in terms of calibration and non-linearity evaluation, and will be deployed in the NUCLEUS setup in its final configuration.
The NUCLEUS target detectors are expected to respond equally to both electron and nuclear recoils. To validate this, the NUCLEUS collaboration conducted a calibration campaign using the absorption of thermal neutrons from the nuclei present in the target detectors. The absorption produces an excited nuclear state that, by decaying to its ground state, generates a high energetic photon, that escapes detection, and a nuclear recoil of 100~eV, exactly in the region of interest of the NUCLEUS experiment. Detecting an interaction at 100~eV with a noise level of 10~eV (as for the NUCLEUS detectors) is difficult due to the low signal-to-noise ratio. Therefore, a suitable data analysis procedure was developed and used to observe the first direct detection of nuclear recoils with the NUCLEUS target detectors, achieving a significance. Since neutrinos interacting via \cevns produce nuclear recoils in the same 100~eV energy range, this data was the perfect test-bed to define the fundamental analysis aspects that need to be followed for a fruitful neutrino detection. Due to the importance of the developed data analysis, a thorough description is presented in this work along with the results of the nuclear recoil calibration.
At the time of completing this thesis, the NUCLEUS collaboration commissioned its experimental setup and performed a long background characterization campaign. The interplay between the main subsystems, including LANTERN, was demonstrated and stable operation of the NUCLEUS detectors over an extended period of time (a few weeks) was achieved. The analysis of the data taken during this period is defined and presented in this work, with focus on the development of the first combined use of the active muon veto and target detectors as devised for the final configuration of NUCLEUS setup. At the end of this thesis, a discussion over the achieved background results is conducted.
In summary, this thesis presents an overview of the \cevns interaction and the status of its searches with focus on the NUCLEUS experiment, which is the experimental context of this work. The central theme of this dissertation is the characterization and use of the cryogenic calorimeters employed for the detection of nuclear recoils at the few hundreds of electron volt scale. This topic is addressed from both the experimental and the analysis points of view, with the development of an optical calibration, as well as assessing the accuracy of these new procedures with the observation of calibrated nuclear recoils induced by neutron absorption. Finally, the results of the background characterization campaign and the setup commissioning are shown
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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