Spectral Data and Grotrian Diagrams for Highly Ionized Vanadium, V VI through V XXIII

Dielectronic recombination (DR) has been studied in highly charged Helike Ti ions using an electron beam ion trap. X-rays emitted from radiative recombination (RR) and DR were observed as the electron beam energy was scanned through the resonances. Differential DR resonant strengths were determined by normalizing the DR x-ray intensity to the RR intensity using theoretical RR cross sections. KLn (2 n 5) resonant strengths were determined for He-like Ti ions. The differential resonant strengths were calibrated without reference to any theoretical DR calculations while the electron energy scale was derived with reference to the well-known energy for ionization of the He-like and H-like ions from the ground state. Calibration in this way facilitates a more exacting comparison between theory and experiment than has been reported previously. To facilitate this comparison, total and differential theoretical resonance strengths were calculated. These calculations were found to be in good agreement with the measured results.

Section: Discussionmentioning

confidence: 99%

“…is the ionization energy of H-like Ti ions. Hence the electron beam energy scale was determined with reference to well-known x-ray energies from radioisotopes [28] and ionization energies of He and H-like ions [29].…”

Section: Discussionmentioning

confidence: 99%

Dielectronic recombination in He-like titanium ions

O’Rourke

Kuramoto²,

et al. 2004

“…Critical data compilations based on the available theoretical and experimental sources are given in [48][49][50][51][52][53][54][55] and online [56]. We refer to these compilations as recommended National Institute of Standards and Technology (NIST) data in the text below.…”

Section: Introductionmentioning

confidence: 99%

Relativistic many-body calculations of electric-dipole lifetimes, transition rates and oscillator strengths for 2l⁻¹3l′ states in Ne-like ions

Cowan

2005

Transition rates, oscillator strengths and line strengths are calculated for electric-dipole (E1) transitions between odd-parity 2s22p53s, 2s22p53d and 2s2p63p states and even-parity 2s22p53p, 2s2p63s and 2s2p63d states in Ne-like ions with the nuclear charges ranging from Z = 14 to 100. Relativistic many-body perturbation theory (RMBPT), including the Breit interaction, is used to evaluate retarded E1 matrix elements in length and velocity forms. The calculations start from a 1s22s22p6 Dirac–Fock potential. First-order RMBPT is used to obtain intermediate coupling coefficients and second-order RMBPT is used to calculate transition matrix elements. Contributions from negative-energy states are included in the second-order E1 matrix elements to ensure the gauge independence of transition amplitudes. Transition energies used in the calculation of oscillator strengths and transition rates are from second-order RMBPT. Lifetimes of the 16 even-parity and 18 odd-parity levels are given for Z = 14–100. Transition rates, line strengths and oscillator strengths are compared with critically evaluated experimental values and with results from other recent calculations. These atomic data are important in the modelling of L-shell radiation spectra of heavy ions generated in electron beam ion trap experiments and in L-shell diagnostics of plasmas.

“…The experimental results were gathered and critically evaluated by a group at the National Institute of Standards and Technology (NIST). We have used the resulting data [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] for comparison. Recently, energies of 2l3l -2l2l transitions in Be-like xenon (Z = 54) were measured at the Grand Accelerateur National d'Ions Lourds (GANIL) at Caen using the Lawrence Livermore National Laboratory highresolution dual-crystal spectrometer [25].…”

Section: Introductionmentioning

confidence: 99%

Relativistic many-body calculations of energies ofn= 3 states of Be-like ions

Johnson

1997

Be-like ions with nuclear charges Z in the range 4-30 and for Z = 54 are determined to second order in relativistic many-body perturbation theory starting from a frozen-core Dirac-Fock basis. Secondorder Coulomb and second-order Breit-Coulomb correlation energies are evaluated. Corrections for the frequency dependence of the Breit interaction are taken into account in lowest order. Lamb-shift corrections to the energies are also included in lowest order. Comparisons are made with other theoretical calculations and with experimental data. We obtain an excellent agreement with experiment for term splitting, even for low-Z ions. Results for the 2p-3d excitation energies for Xe 50+ are also in very good agreement with experiment.