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.
Cowan Code: 50 Years of Growing Impact on Atomic Physics
The famous Cowan’s book, “The Theory of Atomic Structure and Spectra”, published in 1981, and his suite of computer codes based on it, continue to be highly influential in atomic physics and many other research areas. As of September 2018, there have been more than 5000 citations to Cowan’s book and codes, and each year adds about 150 citations to this list. The present work briefly describes what these codes do and why they are responsible for most of the current progress in the analyses of atomic spectra. Various modifications of these codes, including my own, will also be described.
The analysis of the 5d3, 5d26s and 5d26p configurations of quadruply ionized rhenium (Re V)
The spectrum of rhenium was photographed in the 300-2000 A region on a 3m normal incidence spectrograph using a triggered spark and a sliding spark source. The (5d3 + 5d26s)–5d26p transitions of Re V were analysed. All 19 levels of the 5d3 configuration, 15 of 16 levels of the 5d26s configuration and all 45 levels of the 5d26p configuration have been established. 381 lines have been classified in Re V. The least-squares-fitted (LSF) and Hartree-Fock (HF) calculations satisfactorily interpret the spectrum.