New Spectral analysis of the Spectrum of the Zn-Like KrVII Ion

M.O. GALLARDO; J.O. SOUZA; E.E. FARIAS; M. RAINERI; J.G. REYNA ALMANDOS; E. LOPES DE AMORIM

Brasilia

Encuentro; 12º Encontro Brasileiro de Física dos Plasmas; 2013

UnB

In the last years our group has been devoted to the study of medium and highly ionized noble gases using plasma source. Continuing this line we are presenting a revised and extended analysis of the Zn-like Kr VII ion. The spectra of this sequence are of considerable interest for the diagnosis of high-temperature plasmas and very recently, the first detection of Kr VII in a white dwarf was also reported [1]. The purpose of the present study is to provide new data of atomic structure for the six times ionized krypton, including the analysis of new configurations that were not reported in previous works [2, 3]. Krypton experimental data from two different plasma light sources (a theta-pinch and a capillary discharge) were used. In both cases the energy was fed into the plasma using a capacitor bank, charged from a high-voltage power supply. The pressure range was varied between 20 and 300 mTorr. To support the analysis, other experimental data from the Zn-like isoelectronic sequence (nuclear charges Z = 30 - 47) and atomic calculations were also used. Initially we made a revised study of the 4p4d configuration and after that we studied the 4s6p, 4p5s and 4s5f odd parity configurations and also the 4s6d even parity configuration. New experimental energy level values, wavelengths and transition rates were determined which were in good agreement with the theoretical predictions. Atomic calculations for the structure of the configurations were obtained by diagonalizing the energy matrices with appropriately scaled relativistic Hartree-Fock (HFR) values for the energy parameters. For this purpose the computer code developed by Cowan [4] was used. This study was carried out in collaboration with researchers of the Centro de Investigaciones Opticas, CIOp (La Plata, Argentina). [1] Werner, K., Rauch, T., Ringat, E. and Kruk, J.W., The Astrophysical Journal Letters 753:l7, 2012 [2] Churilov, S. S., Optics and Spectroscopy, vol.93, no 6, p.826-832, 2002. [3] Raineri , M., Trigueiros, A. G., Gallardo, M. and Reyna Almandos, J. G., Physica Scripta, vol. 62, p.474-478, 2000. [4] Cowan, R.D. The Theory of Atomic Structure and Spectra. Berkeley, C.A.: University of California Press, 1981.