Author
E. Krishnakumar
Other affiliations: Free University of Berlin, California Institute of Technology, Raman Research Institute ...read more
Bio: E. Krishnakumar is an academic researcher from Tata Institute of Fundamental Research. The author has contributed to research in topics: Ion & Electron ionization. The author has an hindex of 25, co-authored 126 publications receiving 2148 citations. Previous affiliations of E. Krishnakumar include Free University of Berlin & California Institute of Technology.
Papers published on a yearly basis
Papers
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Abstract: A pulsed electron beam and ion extraction method is used to measure normalized values of partial ionization cross sections for rare gases from threshold to 1000 eV. Cross sections obtained for singly ionized species are used to calibrate the mass transmission efficiency of the ion extraction/analyzer/detection system by the relative flow technique, and this mass transmission curve is then used to determine the absolute cross sections of the multiply ionized species. Total ion cross sections are found by summation of the individual partial cross sections with proper weighting for charge.
255 citations
Tomsk State University1, Drake University2, Universidade Católica de Brasília3, International Atomic Energy Agency4, University of Cambridge5, National Autonomous University of Mexico6, California Institute of Technology7, Harvard University8, Centre national de la recherche scientifique9, Uppsala University10, University College London11, Tata Institute of Fundamental Research12, INAF13, National Research Nuclear University MEPhI14, University of Belgrade15, University of Manchester16, Open University17, Queen's University Belfast18, École Polytechnique19, University of Mons20, University of Innsbruck21, National Institute of Standards and Technology22, Russian Academy of Sciences23, University of Cologne24, University of Grenoble25, University of Reims Champagne-Ardenne26
TL;DR: This paper describes how the VAMDC Consortium is organised for the optimal distribution of atomic and molecular data for scientific research and urges authors of research papers using data cite the original experimental and theoretical papers as well as the relevant databases.
Abstract: The Virtual Atomic and Molecular Data Centre (VAMDC) Consortium is a worldwide consortium which federates atomic and molecular databases through an e-science infrastructure and an organisation to support this activity. About 90% of the inter-connected databases handle data that are used for the interpretation of astronomical spectra and for modelling in many fields of astrophysics. Recently the VAMDC Consortium has connected databases from the radiation damage and the plasma communities, as well as promoting the publication of data from Indian institutes. This paper describes how the VAMDC Consortium is organised for the optimal distribution of atomic and molecular data for scientific research. It is noted that the VAMDC Consortium strongly advocates that authors of research papers using data cite the original experimental and theoretical papers as well as the relevant databases.
140 citations
TL;DR: In this paper, a set of electron impact ionization cross-section data for O2 for electron impact energies from threshold to 1000 eV was generated using a crossed electron beam-molecular beam collision geometry and the relative flow technique measurements.
113 citations
TL;DR: The results point to a simple way of controlling chemical reactions as well as interpreting the DEA data from bigger biological molecules.
Abstract: Functional group dependence is observed in the dissociative electron attachment (DEA) to various organic molecules in which the DEA features seen in the precursor molecules of the groups are retained in the bigger molecules. This functional group dependence is seen to lead to site-selective fragmentation of these molecules at the hydrogen sites. The results are explained in terms of the formation of core-excited Feshbach resonances. The results point to a simple way of controlling chemical reactions as well as interpreting the DEA data from bigger biological molecules.
108 citations
TL;DR: In this paper, a megaelectronvolt beam of atoms is generated by ionizing argon clusters, and then neutralizing the ions using Rydberg atoms, which demonstrates a high neutral yield and could find an important application as a sensitive probe of matter.
Abstract: A megaelectronvolt beam of atoms is now generated by ionizing argon clusters, and then neutralizing the ions using Rydberg atoms. The compact system demonstrates a high neutral yield, and could find an important application as a sensitive probe of matter.
78 citations
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TL;DR: In this paper, a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) is presented.
Abstract: Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These
9,929 citations
TL;DR: In this paper, a non-equilibrium discharge in nitrogen-oxygen mixtures is developed, which almost wholly describes chemical transformations of particles in the cold (200 K
Abstract: A kinetic scheme for non-equilibrium discharge in nitrogen-oxygen mixtures is developed, which almost wholly describes chemical transformations of particles in the cold (200 K
1,558 citations
Ohio State University1, University of Iowa2, University of Antwerp3, University of Minnesota4, Stanford University5, University of Bologna6, Ruhr University Bochum7, Centrum Wiskunde & Informatica8, Eindhoven University of Technology9, University of Illinois at Urbana–Champaign10, University of Bari11, University of California, Berkeley12, Osaka University13, Indiana University14, Nagoya University15, Princeton Plasma Physics Laboratory16, University of Michigan17, Open University18, University of Orléans19, Clarkson University20, University of Greifswald21, Toyohashi University of Technology22, University of Poitiers23, Commonwealth Scientific and Industrial Research Organisation24, United States Department of Agriculture25, University of Maryland, College Park26, University of Belgrade27, University of Toulouse28, Tsinghua University29, Applied Materials30, University of Shiga Prefecture31, Tohoku University32, University College London33, University of Tokyo34, Dublin City University35, University of Limoges36
TL;DR: The 2017 plasmas roadmap as mentioned in this paper is the first update of a planned series of periodic updates of the Plasma Roadmap, which was published by the Journal of Physics D: Applied Physics in 2012.
Abstract: Journal of Physics D: Applied Physics published the first Plasma Roadmap in 2012 consisting of the individual perspectives of 16 leading experts in the various sub-fields of low temperature plasma science and technology. The 2017 Plasma Roadmap is the first update of a planned series of periodic updates of the Plasma Roadmap. The continuously growing interdisciplinary nature of the low temperature plasma field and its equally broad range of applications are making it increasingly difficult to identify major challenges that encompass all of the many sub-fields and applications. This intellectual diversity is ultimately a strength of the field. The current state of the art for the 19 sub-fields addressed in this roadmap demonstrates the enviable track record of the low temperature plasma field in the development of plasmas as an enabling technology for a vast range of technologies that underpin our modern society. At the same time, the many important scientific and technological challenges shared in this roadmap show that the path forward is not only scientifically rich but has the potential to make wide and far reaching contributions to many societal challenges.
677 citations
TL;DR: The UMIST Database for Astrochemistry (UDfaa) as discussed by the authors contains 6173 gas-phase reactions involving 467 species, 47 of which are new to this release.
Abstract: We present the fifth release of the UMIST Database for Astrochemistry (UDfA). The new reaction network contains 6173 gas-phase reactions, involving 467 species, 47 of which are new to this release. We have updated rate coefficients across all reaction types. We have included 1171 new anion reactions and updated and reviewed all photorates. In addition to the usual reaction network, we also now include, for download, state-specific deuterated rate coefficients, deuterium exchange reactions and a list of surface binding energies for many neutral species. Where possible, we have referenced the original source of all new and existing data. We have tested the main reaction network using a dark cloud model and a carbon-rich circumstellar envelope model. We present and briefly discuss the results of these models.
608 citations
TL;DR: In this article, the binary encounter Bethe (BEB) model is applied to neutral molecules, which combines the binary-encounter theory and the Bethe theory for electron impact ionization, and uses minimal theoretical data for the ground state of the target molecule.
Abstract: A theoretical model for electron‐impact ionization cross sections, which has been developed primarily for atoms and atomic ions, is applied to neutral molecules. The new model combines the binary‐encounter theory and the Bethe theory for electron‐impact ionization, and uses minimal theoretical data for the ground state of the target molecule, which are readily available from public‐domain molecular structure codes such as GAMESS. The theory is called the binary‐encounter Bethe (BEB) model, and does not, in principle, involve any adjustable parameters. Applications to 19 molecules, including H2, NO, CH2, C6H6, and SF6, are presented, demonstrating that the BEB model provides total ionization cross sections by electron impact from threshold to several keV with an average accuracy of 15% or better at the cross section peak, except for SiF3. The BEB model can be applied to stable molecules as well as to transient radicals.
483 citations