The 4d–4p transitions and soft X-ray laser wavelengths in Si-like ions

Abstract

The transitions between 4p and 4d levels have been studied to examine the possibility of laser wavelength production in the soft X-ray region. The oscillator strengths of the transitions 3p4p ( 3 S, 3 P, 3 D) ¡ 3p4d ( 3 P o , 3 D o , 3 F o ) have been calculated using CIV3 code. Using calculated oscillator strengths, the excitation rate coefficients, reduced populations, and gain coefficients for Si-like Ni XV, Zn XVII, Ga XVIII, Ge XIX, and As XX at electron temperatures 1/4, 1/2, and 3/4 the ionization potential have been calculated. The method by Palumbo and Elton has been used in the calculation of laser parameters. The present calculated data show promising values for the production of laser wavelengths in the soft X-ray region. The maximum values of the gain factor lie within the range ␣ ϳ 10 9 cm −1 and wavelength ≤ 469 Å. PACS Nos.: 30., 32.30.-r, 42.55.-f, 52.50.Jm.Résumé : Nous étudions les transitions entre les niveaux 4p et 4d, afin d'examiner la possibilité de produire des lasers dans la longueur d'onde des rayons X mous. Utilisant le programme CIV3, nous calculons les forces d'oscillateur des transitions 3p4p ( 3 S, 3 P, 3 D) ¡ 3p4d ( 3 P 0 , 3 D 0 , 3 F 0 ). Utilisant ces forces d'oscillateur calculées, nous évaluons les coefficients de taux d'excitation, les populations réduites et les coefficients de gain des ions de type Si suivants : Ni XV, Zn XVII, Ga XVIII, Ge XIX et As XX, aux températures égales à 1/4, 1/2 et 3/4 du potentiel d'ionisation. Nous utilisons la méthode de Palumbo et Elton pour calculer les paramètres laser. Les valeurs calculées sont prometteuses pour la production de laser X mous. Les valeurs maximales pour le facteur de gain sont autour de ␣ ϳ 10 9 cm −1 et la longueur d'onde est ≤ 469 Å. [Traduit par la Rédaction]

Population Inversion and X-Ray Laser Gain by Electron Impact Excitation of Ni-Like Tin

“…The configuration array 3d 9 4d upper laser levels are more populated than the 3d 9 4p lower laser levels in electron collisional excitation. In spite of the fact that the 3d 9 4d upper laser levels are optically forbidden and have no optical connection to the ground level, and it is strongly optically connected to the 3d 9 4p levels therefore laser transition is favorable [36]. The population inversion is largest where electron collisional de-excitation rate for upper level is comparable to the radiative decay for this level [18,24].…”

Advances in atomic physics

“…8 and 9 . The studies include helium isoelectronic sequence [77] , beryllium isoelectronic sequence [69,78] , boron isoelectronic sequence [79–81] , carbon isoelectronic sequence [82] , sodium isoelectronic sequence [83–85] , magnesium isoelectronic sequence [86–88] , aluminum isoelectronic sequence [89] , silicon isoelectronic sequence [90–92] , sulfur isoelectronic sequence [93] , potassium isoelectronic sequence [94] , scandium isoelectronic sequence [95] , and nickel isoelectronic sequence [96] . Most of the heavy members of the isoelectronic sequences studied radiate in the XUV and Soft X-Ray spectral regions ( λ between 50 and 1000 Å).…”