Abstract: An almost complete set of electron-molecule cross sections has been assembled independently from the databases that are currently in use on LXCat. The assembly combined an exhaustive gathering (up to 2022) of experimental cross sections, accurate quantum mechanical calculations and simple analytical representations. The modelling of elastic scattering is based on our article for calculating differential cross sections of electrons scattering elastically from diatomic molecules. A thorough documentation of the process for constructing the new cross section database is included as well. It provides an overview of techniques for fitting experimental data and comparisons of various electron-molecule cross section databases currently in use.

Abstract: A simple model is proposed to compute electron-diatomic molecule elastic differential cross-sections at intermediate energies within the framework of an analytical local optical potential. In a spherical harmonic expansion of the molecular potential we treat the isotropic term with the partial-wave decomposition and apply the independent atom model (IAM) on all higher orders. This model is seen to properly converge to the IAM at high energies, while bringing significant improvement at lower energies. We compare the results with a well-tested program called ELSEPA, tailored for high-energy electron-atom scattering and address its further extension to molecules with the method proposed. The simplicity of the calculations and the encouraging agreement in shape with experimental data could promote attractiveness among plasma physics simulations in need of coherent and well-resolved differential cross-sections.

Abstract: This document is for new contributors to LXCat.

Abstract: Technologies based on non-equilibrium, low-temperature plasmas are ubiquitous in today’s society. Plasma modeling plays an essential role in their understanding, development and optimization. An accurate description of electron and ion collisions with neutrals and their transport is required to correctly describe plasma properties as a function of external parameters. LXCat is an open-access, web-based platform for storing, exchanging and manipulating data needed for modeling the electron and ion components of non-equilibrium, low-temperature plasmas. The data types supported by LXCat are electron- and ion-scattering cross-sections with neutrals (total and differential), interaction potentials, oscillator strengths, and electron- and ion-swarm/transport parameters. Online tools allow users to identify and compare the data through plotting routines, and use the data to generate swarm parameters and reaction rates with the integrated electron Boltzmann solver. In this review, the historical evolution of the project and some perspectives on its future are discussed together with a tutorial review for using data from LXCat.

Abstract: This file merges all presentations made during the discussion session with the exception talk presented by Jacob Stephens which was a walk through the website.

Abstract: Racah and Paschen notation are two common notatin schemes for excited atomic levels. This document contains a set of tables to aid in the conversion between the two notations. These tables are taken from the PhD thesis of Wouter Graef.

Abstract: It has come to our attention that certain commercial interests may have incorporated data downloaded from the LXCat site directly into their commercial products. Consequently, it appears necessary to elaborate a policy statement about redistribution of data by third parties. The purposes of the policy are to ensure the integrity of data circulating through the community, to give LXCat contributors and people who generate data proper credit for their work, and to maintain the visibility of LXCat as an open-access source of data needed for modeling plasmas.

Abstract: LXCat is an open-access platform (www.lxcat.net) for curating data needed for modeling the electron and ion components of technological plasmas. The data types presently supported on LXCat are scattering cross sections and swarm/transport parameters, ion-neutral interaction potentials, and optical oscillator strengths. Twenty-four databases contributed by different groups around the world can be accessed on LXCat. New contributors are welcome; the database contributors retain ownership and are responsible for the contents and maintenance of the individual databases. This article summarizes the present status of the project.

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. (OPEN ACCESS).

Abstract: LXCat is a web-based, community-wide project on the curation of data needed in the modelling of low-temperature plasmas. LXCat is organized in databases, contributed by members of the community around the world and indicated by the contributor's chosen title. This paper presents the status of the data available on the IST-LISBON database with LXCat. IST-LISBON contains up-to-date electron-neutral collisional data (together with the measured swarm parameters used to validate these data) resulting from the research effort of the Group of Gas Discharges and Gaseous Electronics with Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Lisbon, Portugal. Presently, the IST-LISBON database includes complete and consistent sets of electron scattering cross sections for argon, helium, nitrogen, oxygen, hydrogen and methane.

Abstract: LXCat is an open-access website (www.lxcat.net) for exchanging data related to ion and electron transport and scattering cross sections in cold, neutral gases. At present 30 people from 12 countries have contributed to the LXCat project. This presentation will focus on the status of the data available for electrons on LXCat. These data are primarily in the form of ``complete'' sets of cross sections, compiled or calculated by different contributors, covering a range of energies from thermal up to about 1 keV. The cross section data can be used directly in Monte Carlo simulations and can also be used as input to Boltzmann equation solvers. Solution of the homogeneous, steady-state Boltzmann equation yields electron energy distribution functions (edf) as a function of reduced electric field strength, E/N, integrals over which yield electron transport and rate coefficients. The transport and rate coefficient data are required input for fluid models of low temperature plasmas. Evaluation of the cross section data sets available on LXCat is a key issue. To this end, the LXCat team has been making systematic intercomparisons of cross section data and comparisons of calculated and measured transport and rate coefficients. Our evaluations have been reported previously for noble gases and for common atmospheric gases. The LXCat team is now evaluating data for more complex molecules.

Abstract: LXCat (for ELECtron SCATtering) is an open-access website for exchanging data related to ion and electron transport and scattering cross sections in cold, neutral gases. Such data are essential for the modeling of low temperature plasmas. At present, 22 databases contributed by groups around the world can be accessed on LXCat. On-line tools enable importing and exporting data, plotting and comparing different sets of data, and for downloading data.

Abstract: This paper describes work done in the context of the Gaseous Electronics Conference (GEC) Plasma Data Exchange Project (PDEP) as discussed in the preface to this cluster issue. The purposes of this paper and its companion papers are to compare sets of cross sections for electron scattering from ground-state noble gas atoms in the energy range from thermal to about 1 keV and to comment on their applicability for plasma modelling. To these ends, we present in this paper intercomparisons of the nine independently derived sets of cross sections for electron scattering from ground-state argon atoms that have been posted in databases on the LXCat open-access website (www.lxcat.laplace.univ-tlse.fr). We show electron transport, excitation and ionization coefficients (swarm parameters) calculated using these cross section data in Boltzmann solvers and we compare calculated values with measurements. For the most part, the cross section sets have been compiled by co-authors on this paper and appendices giving details about how the various cross sections datasets were compiled have been written by the individual co-authors. Additional appendices discuss our criteria for selection of experimental data to be included in the comparisons and give a brief overview of the methods used here for solving the Boltzmann equation.

Abstract: This paper is the second of a series of four reports, describing work carried in 2011 in the context of the Plasma Data Exchange Project with the Gaseous Electronics Conference, devoted to intercomparisons between different sets of electron–neutral scattering cross sections from ground-state noble gas atoms, in the energy range from thermal to about 1 keV. The present work compares cross section sets for helium and neon, determined independently, which are available on the open access LXCat website (www.lxcat.laplace.univ-tlse.fr/). The cross sections are used as input data in an electron Boltzmann solver or in Monte Carlo simulations, to calculate different swarm parameters (transport parameters and rate coefficients). The calculated quantities are compared with measurements to assess the quality of the cross sections in providing data for modelling low-temperature plasmas or analysing experiments. The paper includes several appendices prepared by co-authors to the work, presenting details on how the various cross section datasets were compiled or evaluated.

Abstract: This paper, the third in a series of three, describes work carried in the context of Plasma Data Exchange Project of the Gaseous Electronics Conference (PDEP-GEC) to compare electron collision cross-sections sets from ground-state, noble gases atoms and to check their consistency with measured swarm parameters. Such consistency is a minimum requirement if the cross-section data are to be used for modelling low-temperature plasmas. In this paper, we present intercomparisons of the independently compiled sets of electron cross-sections from ground-state, neutral Kr and Xe atoms presently available on the LXCat open-access website (www.lxcat.laplace.univ-tlse.fr). Swarm parameters (reduced mobility, characteristic energy, reduced longitudinal diffusion coefficient, reduced ionization coefficient) calculated in a Boltzmann solver or Monte Carlo simulation using these cross-sections sets are compared with experimental data, also available online on the LXCat site.

Abstract: In 2010 the Gaseous Electronics Conference (GEC), a major international conference for the low temperature plasma science (LTPS) community, initiated the Plasma Data Exchange Project (PDEP). The PDEP is an informal, community-based project that aims to address, at least in part, the well-recognized needs for the community to organize the means of collecting, evaluating and sharing data both for modelling and for interpretation of experiments. The emphasis to date in the PDEP has been on data related to the electron and ion components of these plasmas rather than on the plasma chemistry. At the heart of the PDEP is the open-access website, LXCat [1], developed by researchers at LAPLACE (Laboratoire Plasma et Conversion d'Energie, Toulouse, France). LXCat is a platform for archiving and manipulating collections of data related to electron scattering and transport in cold, neutral gases, organized in databases set-up by individual members or institutions of the LTPS community. At present, 15 databases of electron scattering data, contributed by groups around the world, can be accessed on LXCat. These databases include complete sets of electron cross sections, over an energy range from thermal to nominally 1 keV, for almost 40 ground-state neutral species and partial sets of data for about 30 other neutral, excited and ionized species. 'Complete' implies that all the major electron momentum and energy loss processes are well described in the dataset. Such 'complete' datasets can be used as input to a Boltzmann calculation of the electron energy distribution function (generally non-Maxwellian), and electron transport and rate coefficients can be obtained in pure gases or mixtures by averaging over the distribution function. Online tools enable importing and exporting data, plotting and comparing different sets of data. An online version of the Boltzmann equation solver BOLSIG+ [2] is also available on the LXCat site. Other members of the community have contributed their collections of transport and rate coefficient data, and comparisons of calculated and measured data can also be made online through the LXCat site. A large body of data for ion scattering and transport is available on the sister site, ICECat [3], which is now being merged into a new and improved LXCat platform [4] under development. The GEC hosted workshops on the PDEP in 2011 and 2012, with the third in the series being planned for October 2013. The purpose of these workshops has been to report progress towards the evaluation of data available on LXCat or elsewhere. The focus of the 2011 workshop was electron scattering and transport in noble gases, and the articles in this cluster issue were originally reported at that occasion. The 2012 workshop focused on electron transport in simple molecular gases, and plans are to publish documentation and evaluations of datasets for H2, N2 and O2, as reported at the 2012 GEC. The focus topic for the 2013 workshop is electron scattering in H2O and other complex molecules. The first three papers (paper I on Ar, by Pitchford et al [5], paper II on He and Ne, by Alves et al [6], and paper III on Kr and Xe, by Bordage et al [7]) in this cluster issue aim to provide documentation of the datasets available on LXCat for noble gases. Paper IV by Klaus Bartschat [8] gives an overview of theoretical methods for calculations of electron–atom scattering cross sections. This is important because, in some cases, theory has now advanced to the point of being able to provide complete sets of electron scattering cross-sections in noble gases to the accuracy required for use in plasma modelling. The discussion provided in the four papers in this cluster issue is intended to help users decide which datasets best fit their needs. We urge the users of these data to include complete and proper references in all publications. Open-access data should not become anonymous data! Finally, it is with sadness that we acknowledge the passing of our colleague Art Phelps in December 2012. Art was a key person on the GEC Plasma Data Exchange Project and a major contributor to the LXCat site, having made available his compilations of electron and ion scattering cross sections as well as many of his unpublished notes and documents on related issues. Throughout his long and remarkably productive career, Art Phelps held the bar high for the entire GEC community. We can only aspire to his example. We dedicate this cluster issue to him with the knowledge that he could have improved on these papers but with the hope that he would have been satisfied with their final versions.

Abstract: Transport and reaction coefficients for electrons in Ar, H2, N2, O2, and dry air calculated using the cross sections in ELECTRON_CS.pdf.

Abstract: Collision cross sections for electrons with H2, N2, O2, CO2, H2O, NO, SF6, He, Ne, Ar, Kr, Xe, Mg, and Na. These are all of the electron cross sections assembled by Phelps and coworkers for use with the Boltzmann code BACKPRO. Comments on more recent work are added.

Abstract: We present a description of the sets of electron-neutral scattering cross sections for N2 (4 sets) and for O2 (4 sets) presently available on the open-access LXCat site (www.lxcat.net). Three of these sets are complete in that the main momentum and energy loss processes are taken into account, if we can neglect internal excitation in the gas, and were derived using the requirement that they be consistent with available experimental swarm data. The fourth set consists of recommended values from beam experiments and theory. We describe these cross section sets and show, for each, comparisons of calculated swarm parameters with selected experimental data.

Abstract: The GEC Plasma Data Exchange Project is an informal effort on the part of the low temperature plasma community to organize the collection, evaluation, and distribution of data both for modeling and for interpretation of experiments. In the context of this project, we present a description of the four independently-compiled sets of electron-neutral scattering cross sections for H2 presently available on the open-access LXCat site (www.lxcat.net). Three of these sets were derived using the requirement that they be consistent with available experimental swarm data, and the fourth set consists of recommended values from beam experiments and theory. To assess the validity of each of these cross section sets for use in modeling low temperature plasmas, we calculated electron transport and rate coefficients using these cross sections as input and compared with measured values also available on the LXCat site. We also show the influence of rotational temperatures between 77 and 300 K, and again confirm that a two-term Boltzmann solver yields results in very good agreement with Monte Carlo simulations.

Abstract: A review the available data and mechanisms for electron attachment and detachment and ion stabilization for dry air at E/n near the cross over between net attachment and ionization.

Abstract: Gaseous Electronics Conference - GEC 2011, Poster - Extensive data are available in the literature for cross sections for electron-neutral scattering from argon and for swarm parameters in argon and argon-containing gas mixtures. Seven independently compiled sets of cross sections in argon are presently available on the LXCat website, including one set of data derived from theory. The recent theoretical elastic momentum transfer cross section is in excellent agreement with recent results from a swarm analysis. The purpose of this communication is to show intercomparisons of swarm parameters calculated using these different sets. For the most part and within the accuracy required for plasma modeling, calculated swarm parameters using the different cross section sets agree with experiment and among themselves. Swarm parameters calculated using classic 2-term Boltzmann solvers are in good agreement with those from Monte Carlo simulations except for the diffusion coefficients, where the 2-term approximation overestimates the values by about 30% in the 5 to 100 Td range. The cross section sets and measured swarm parameters used in this work are available on-line at LXCAT website.

Abstract: Gaseous Electronics Conference - GEC 2011, Poster - In the context of the recently initiated GEC Plasma Data Exchange project, we compare measured swarm parameters with those calculated using sets of cross sections, compiled by different authors, in helium and neon. These data are on-line at www.lxcat.laplace.univ-tlse.fr. The cross section compilations for electron scattering from ground state helium or neon vary mainly in the level of detail provided for inelastic excitation, ranging from one effective excitation level to many individual levels. The swarm parameters were calculated using a 2-term Boltzmann solver and a Monte Carlo simulation. Calculated swarm parameters from the various compilations show good agreement among themselves in both gases, and generally good agreement is obtained between calculated and measured swarm parameters except for ionization coefficients at low E/N where measured ionization coefficients in both gases show strong influences of Penning ionization of impurities. We conclude that the cross section compilations and their use in a 2-term Boltzmann solver yield results sufficiently accurate for plasma modeling purposes.

Abstract: Gaseous Electronics Conference, GEC 2011, Poster - Xenon is used in a number of application areas ranging from light sources to x-ray detectors for imaging in medicine, border security and high-energy particle physics. There is a correspondingly large body of data available for electron scattering cross sections and swarm parameters in Xe, whereas data for Kr are more limited. In this communication we show intercomparisons of the cross section sets in Xe and Kr presently available on the LXCat site. Swarm parameters calculated using these cross sections sets are compared with experimental data, also available on the LXCat site. As was found for Ar, diffusion coefficients calculated using these cross section data in a 2-term Boltzmann solver are higher than Monte Carlo results by about 30{\%} over a range of E/N from 1 to 100 Td. We find otherwise good agreement in Xe between 2-term and Monte Carlo results and between measured and calculated values of electron mobility, ionization rates and light emission (dimer) at atmospheric pressure. The available cross section data in Kr yield swarm parameters in agreement with the limited experimental data. The cross section compilations and measured swarm parameters used in this work are available on-line at LXCAT website.

Abstract: The LXCat project is an open-access website for exchanging data related to electron scattering and transport in cold, neutral gases, critically important to modeling low temperature plasmas, by using Boltzmann or Monte Carlo codes.

Abstract: The open-access, on-line databases available on www.lxcat.net contain data relevant to electron and ion scattering and transport in low-temperature plasmas, in forms suitable for use in modeling such plasmas. The site was restructured in 2012, and data evaluation is a continuing activity.

Abstract: ICAMDATA 7 21–24 September 2010, Vilnius.

Abstract: ICPIG 2011, LXCat is a dynamic, open-access, website for collecting, displaying, and downloading ELECtron SCATtering cross sections and swarm parameters required for modeling low temperature, non-equilibrium plasmas. Contributors set up individual databases, and the available databases include electron-neutral scattering cross sections or swarm parameters. On-line tools include options for browsing, plotting, and downloading data. The electron energy distribution functions in low temperature plasmas are in general non-Maxwellian, and LXCat provides an option for execution of an on-line Boltzmann equation solver to calculate the edf in homogeneous electric elds. LXCat is part of a larger, community-wide eort aimed at collecting, evaluating, and sharing data relevant to modeling low temperature plasmas.

Abstract: LXCat is a dynamic, open-access, website for collecting, displaying, and downloading ELECtron SCATter- ing cross sections and swarm parameters (mobility, diffusion coefficient, reaction rates, etc.) required for modeling low temperature, non-equilibrium plasmas. Contributors set up individual databases, and the available databases, indicated by the contributor’s chosen title, include mainly complete sets of electron-neutral scattering cross sections, although the option for introducing partial sets of cross sections exists. A database for measured swarm parameters is also part of LXCat, and this is a growing activity. On-line tools include options for browsing, plotting, and downloading cross section data. The electron energy distribution functions (edfs) in low temperature plasmas are in general non- Maxwellian, and LXCat provides an option for execution of an on-line Boltzmann equation solver to calculate the edf in homogeneous electric fields. Thus, the user can obtain electron transport and rate coefficients (averages over the edfs) in pure gases or gas mixtures over a range of values of the reduced electric fields strength, E/N, the ratio of the electric field strength to the neutral density, using cross sections from the available databases. New contributors are welcome and anyone wishing to create a database and upload data can request a username and password. LXCat is part of a larger, commu- nity-wide effort aimed at collecting, evaluating, and sharing data relevant to modeling low temperature plasmas. To illustrate the utility of LXCat in this context, we compare electron swarm parameters in argon calculated using the different compilations of cross sections presently available on LXCat. These compilations include quite different groupings of excited states, yet lead to swarm parameters in good agreement.

Abstract: Cross sections for collisions of electrons, positive and negative ions, and neutral atoms and molecules with H2 and surfaces for modeling low pressure discharges in H2. This file incorporates notes previously posted separately for individual processes.

Abstract: Collision cross sections for identical and non-identical rare-gas atom pairs for energies from 0.01 eV to 10 keV.

Abstract: Differential cross sections for symmetrical ion-atom collisions in the rare gases.

Abstract: The difference between rate coefficients calculated by BOLSIG+ and collision frequencies calculated by the older Boltzmann solver, BOLSIG is described.

Abstract: Description of "effective momentum transfer" cross sections.