3dnd J = 4, 5 autoionizing levels in Ca: laser optogalovanic spectroscopy and theoretical analysis (Journal article)

Assimopoulos, S./ Bolovinos, A./ Luc-Koenig, E./ Cohen, S./ Lyras, A./ Tsekeris, P./ Aymar, M.

We report the even parity J = 4,5 autoionizing spectra of calcium below the 3d threshold, investigated by two-step laser excitation from the 3d4s metastables through the 3d4p F-3(3, 4), F-1(3) intermediate states and subsequent optogalvanic detection. The 3d4s states are populated by electronic collisions in a d.c. glow discharge sustained in a Ca heat-pipe. More than a hundred resonant transitions have been measured with an accuracy of similar to 0.2 cm(-1) for the narrow ones using standard laser calibration techniques. The high lying levels are assigned to all expected 3dnd J = 4, 5 autoionizing series. Moreover, some 3dng J = 4, 5 levels are observed. The theoretical interpretation is achieved by a combination of the nearly ab initio eigenchannel R-matrix and multichannel quantum-defect (MQDT) methods as well as by an empirical determination of the MQDT parameters in the phase-shifted formulation. Theoretical energy level positions and excitation profiles are compared with the experimental data confirming the identification of the observed structures. Strong mixing between 3dnd J = 4 series is found, while the 3dng ones do not couple with the 3dnd series. Further insight into the strong channel mixing in the studied energy range is provided by a comprehensive review of the excitation profiles in the vicinity of the 4p5p D-3(3) perturber as obtained from a number of intermediate levels used in the present and in earlier experiments. Systematic electron correlation trends for Ndnd J = 4 series of Ca(N = 3), Sr(N = 4) and Ba(N = 5) are discussed.
Institution and School/Department of submitter: Πανεπιστήμιο Ιωαννίνων. Σχολή Επιστημών και Τεχνολογιών. Τμήμα Βιολογικών Εφαρμογών και Τεχνολογιών
Keywords: quantum-defect theory,r-matrix calculation,optogalvanic spectroscopy,neutral barium,spectrum,calcium,series,states,limit
URI: https://olympias.lib.uoi.gr/jspui/handle/123456789/16832
ISSN: 1434-6060
Link: <Go to ISI>://000073581700004
Appears in Collections:Άρθρα σε επιστημονικά περιοδικά ( Ανοικτά)

Files in This Item:
File Description SizeFormat 
Assimopoulos-1998-3dnd J = 4, 5 autoio.pdf462.78 kBAdobe PDFView/Open    Request a copy

 Please use this identifier to cite or link to this item:
  This item is a favorite for 0 people.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.