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Temperature anisotropy and rotation upgrades to the ICRF modules in SNAP and TRANSP
Get PDFFokker-Plank and transport codes have significantly better velocity-space treatment of the plasma than do the RF deposition models: FPP uses a 2 or 3D velocity space calculation, TRANSP uses Monte-Carlo particles, e.g., 3D in velocity space, many 2 and 3D spatial RF deposition codes are based on Maxwellians, with a single velocity-space parameter, i.e., the isotropic temperature. The ultimate goal of this effort was to provide the deposition codes with better velocity-space physics. For ICRH heating on TFTR, two important physics issues are velocity-space anisotropy (because of high energy tails), and plasma rotation (because of simultaneous NBI-RF heating). In addition, these two physical effects are among the suite of experimentally measurable quantities, and most of the required new formulas already exist in the literature
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Continued development of modeling tools and theory for rf heating. Final report
Get PDFThe work performed during the grant has been reported long before this date, specifically in: (1) the grant`s annual performance report for 1991, MRC/WDC-R-277; (2) the published AIP Conference Proceedings {number_sign}244, Radio Frequency Power in Plasmas, Charleston, SC 1991, ``Evaluation of Wave Dispersion, Mode-Conversion, and Damping for ECRH with Exact Relativistic Corrections,`` by D.N. Smithe and P.L. Colestock; and (3) an unpublished paper entitled ``Temperature Anisotropy and Rotation Upgrades to the ICRF Modules in SNAP and TRANSP``, presented at the 1992 ICRF Modeling and Theory Workshop, at the Princeton Plasma Physics Laboratory. This final report contains copies of number (1). The specifics of the grant`s final months` activities, which to the authors recollection have never been reported to the DOE, are as follows. The original grant, which was to terminate August 15, 1991, was extended without additional funds to October 31, 1992. The primary reason for the extension was to permit attendance at the 1992 ICRF Modeling and Theory Workshop at the Princeton Plasma Physics Laboratory (PPPL), which was finally held August 17--18, 1992, after having been rescheduled several times during the summer of 1992. The body of this report contains copies of the 1991 annual report, which gives detailed discussion of the work accomplished
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
Local full-wave energy in nonuniform plasmas
Get PDFThe subject of local wave energy in plasmas is treated via quasilinear theory from the dual perspectives of the action-angle formalism and gyrokinetics analysis. This work presents an extension to all orders in the gyroradius of the self-consistent wave-propagation/quasilinear-absorption problem using gyrokinetics. Questions of when and under what conditions local energy should be of definite sign are best answered using the action-angle formalism. An important result is that the ''dielectric operators'' of the linearized wave equation and of the local energy are not the same, a fact which is obscured when the eikonal or WKB assumption is invoked. Even though the two dielectrics are very different in character (one operates linearly on electric field for the plasma current, the other operates quadratically for the energy), it is demonstrated that they are nevertheless related by a simple mathematical statement. This study was originally motivated by concern and lively discussion over the questions of local energy for rf-heating of plasmas, where in certain instances, full-wave effects such as refraction, strong absorption, and mode conversion are of primary importance. Fundamentally, the rf-absorption must equate with the energy moment of the quasilinear term to achieve a correct energy balance. This fact governs the derivation (as opposed to postulation) of the local absorption. The troublesome ''kinetic flux'' may then be chosen (it is not unique) to satisfy a wave-energy balance relation with the Poynting flux and local absorption. It is shown that at least one such choice reduces asymptotically to the Stix form away from nonuniformities, thereby demonstrating energy conservation to all orders in Larmor radius. 25 refs
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Evaluation of wave dispersion, mode-conversion, and damping for ECRH with exact relativistic corrections
No full textThe complex dispersion functions of Eq. (3) in Ref. 1 have recently been computed accurately and reliably over their entire range of parameters, without recourse to the usual slightly-relativistic approximation, which may have difficulty for oblique incidence. In the future, the local dispersion properties of ECRF waves will be reevaluated for parameters of interest to ECRF conditions in several existing and proposed fusion experiments, with particular emphasis on the damping and mode-conversion of both ordinary and extraordinary waves to electrostatic waves near the upper hybrid and cyclotron frequencies
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
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