IDEN2 - A program for visual identification of spectral lines and energy levels in optical spectra of atoms and simple molecules
Abstract The article describes a Java program that can be used in a user-friendly way to visually identify spectral lines observed in complex spectra with theoretically predicted transitions between atomic or molecular energy levels. The program arranges various information about spectral lines and energy levels in such a way that line identification and determination of positions of experimentally observed energy levels become much easier tasks that can be solved fast and efficiently. Program summary Program title: IDEN2 Program Files doi: http://dx.doi.org/10.17632/mwr2tk84sw.1 Licensing provisions: GPLv3 Programming language: Java v.1.8 Nature of problem: Line identification problem in atomic and molecular spectra that have a limited number of previously known low-excited energy levels and a large number of unidentified spectral lines (emission or absorption). The line identification consists of finding the lower and upper energy levels of transitions corresponding to each observed spectral line. Solution method: For each energy level (experimentally known or unknown), the list of observed spectral lines is displayed on a wavenumber scale as an image. This image is repeated with certain vertical shifts in several columns corresponding to other levels connected with the investigated one by theoretically predicted transitions. In each such column, the image of the line spectrum is shifted by the value corresponding to the energy of the connecting level. Then the problem of location of an unknown level is reduced to scrolling the screen until several spectral lines in different columns align along the same horizontal line. Various gadgets provide complete information about all pertinent entities, such as the level identities, wavelengths, observed and calculated intensities. Additional comments including restrictions and unusual features: A practical limitation on the size of the problem is imposed by the available RAM, which is typically sufficient to treat spectra with up to 100 000 spectral lines and 10 000 energy levels. The visual appearance of all gadgets, including font sizes, colors, and window sizes and positions, is completely customizable. An extensive Help system and User Guide are included.
Transition arrays in atomic spectroscopy with a commercial spreadsheet program
In deducing the experimental energy levels of an atom from its observed spectral lines, a two-dimensional transition array showing all the predicted and identified electric-dipole transitions can be of great help. A system for using a commercial spreadsheet program to construct these arrays is described. Use of such a program facilitates the generation of large arrays with little computer coding. The basic principles should be applicable to other areas where it is desired to organize experimental and theoretical data in a two-dimensional array. © 1997 American Institute of Physics.
Continuous calibration of a vacuum ultraviolet system from 65 to 125 nm by a cascade arc and comparison with the calibrated line radiation of a hollow cathode.
A high-power stationary helium cascade arc has been developed as a standard source for continuum radiation in the VUV spectral range from 65 to 125 nm. The calibration of the VUV system response was based on the calculated and measured continuum radiation of a 2-mmphi pure He arc. Diagnostics of the arc plasma in partial thermal equilibrium yielded the electron density and the temperature that were inserted in the calculations of the continuous radiation. The results were compared with the helium, argon, and krypton radiation lines of a high-current hollow cathode lamp. This lamp was built according to the construction drawings of a hollow cathode, which was calibrated by means of the electron synchrotron radiation at the Physikalisch Technische Bundesanstalt Berlin.