Fully relativistic atomic structure calculations for W XLIV for determination of plasma diagnostic terms

2017 ◽  
Vol 95 (10) ◽  
pp. 950-957
Author(s):  
Arun Goyal ◽  
Rinku Sharma ◽  
A.K. Singh ◽  
Man Mohan

We report accurate calculations of W XLIV through application of multi-configuration Dirac–Fock wave functions. We have calculated the energies for the lowest 100 fine structure levels, transition wavelengths, radiative rates, oscillator strengths, and line strengths for electric (E1) and magnetic dipole (M1) transitions with the extended average level multi-configurational Dirac–Fock method in the General-Purpose Relativistic Atomic Structure Package (GRASP). We have taken into account the electron correlations, quantum electrodynamics (QED) and Breit corrections in our calculations. We have also performed parallel calculations with the flexible atomic code (FAC) to assess the accuracy of our calculations. This is a fully relativistic code that provides a variety of atomic parameters, and (generally) yields results for energy levels and radiative rates comparable to GRASP. Our calculated results match well with experimentally observed results that are obtained in ASDEX upgrade Tokamak. Additionally, we have also provided the line intensity ratios and electron density for W XLIV, which is useful and important in plasma diagnostics and modeling in future International Thermonuclear Experimental Reactor (ITER) experiments. We believe that our results would be beneficial in the areas of fusion plasma research and astrophysical investigations and applications.

2014 ◽  
Vol 92 (3) ◽  
pp. 177-183 ◽  
Author(s):  
Man Mohan ◽  
Sunny Aggarwal ◽  
Narendra Singh

Energy levels, lifetimes, and wavefunction compositions have been calculated for all levels of odd parity 3s23p5 ground configuration as well as 3s3p6 and 3s23p43d even parity excited configurations in highly charged Cl-like tungsten ion. Transition probabilities, oscillator strengths, and line strengths for E1, E2, M1, and M2 transitions have been obtained using the fully relativistic multiconfiguration Dirac–Fock (MCDF) approach including the correlations within the n = 3 complex, some n = 3 → n = 4 single and double excitations and Breit and quantum electrodynamics effects. For comparison from our calculated energy levels, we have also calculated the energy levels by using the fully relativistic flexible atomic code (FAC). The validity of the method is assessed by comparison with previously published experimental and theoretical data. The excellent agreement observed between our calculated results and those obtained using different approaches confirm the accuracy of our results. Additionally, we have predicted some new atomic data for W57+ that are not available so far and may be important for plasma diagnostic analysis in fusion plasma.


2015 ◽  
Vol 93 (5) ◽  
pp. 487-495 ◽  
Author(s):  
Arun Goyal ◽  
Indu Khatri ◽  
Sunny Aggarwal ◽  
A.K. Singh ◽  
Man Mohan

Energy levels, wavefunction compositions, and lifetimes are computed for all levels of 4s24p5, 4s24p44d, and 4s4p6 configurations in Br-like ions (Z = 47–50). We use the multiconfigurational Dirac–Fock method to generate the wavefunctions. We also present the transition wavelengths, oscillator strengths, transition probabilities, and line strengths for the electric dipole (E1) transition from the ground state configuration. We compare our calculated results with the available data in the literature and good agreement is obtained, which confirms the quality of our results. Moreover, we predict some new atomic data that have not been available so far and may be important for plasma diagnostic analysis in fusion plasma.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Norah Alonizan ◽  
Rabia Qindeel ◽  
Nabil Ben Nessib

Energy levels and oscillator strengths for neutral oxygen have been calculated using the Cowan (CW), SUPERSTRUCTURE (SS), and AUTOSTRUCTURE (AS) atomic structure codes. The results obtained with these atomic codes have been compared with MCHF calculations and experimental values from the National Institute of Standards and Technology (NIST) database.


2017 ◽  
Vol 95 (4) ◽  
pp. 393-401 ◽  
Author(s):  
K. Wang ◽  
S. Li ◽  
R. Si ◽  
C.Y. Chen ◽  
J. Yan ◽  
...  

Energies, wavelengths, lifetimes, oscillator strengths, electric dipole (E1), electric quadrupole (E2), magnetic dipole (M1), and magnetic quadrupole (M2) transition rates among the 42 fine structure levels belonging to the 3s23p4, 3s23p33d, and 3s3p5 configurations for S-like Fe and S-like ions with 41 ≤ Z ≤ 49 are calculated using the fully relativistic multiconfiguration Dirac–Fock (MCDF) method. In the calculations, contributions from correlations within the n = 6 complex, Breit interaction, and quantum electrodynamics effects are included. Detailed comparisons are made between the present results and the available experimental and other theoretical data. We found that our calculated energy levels generally agree within ≤0.5% with the experimentally compiled results, and the transition rates agree within ≤12% with other theoretical results for a majority of the transitions. These accurate theoretical data should be beneficial in fusion plasma research and astrophysical applications.


2019 ◽  
Vol 97 (4) ◽  
pp. 436-442
Author(s):  
A.K. Singh ◽  
Mayank Dimri ◽  
Dishu Dawra ◽  
Alok K.S. Jha ◽  
Man Mohan

An extended calculation of energy levels, radiative rates, and lifetimes are reported for sodium-like chromium. Extensive configuration interaction calculations have been performed using general-purpose relativistic atomic structure package (GRASP). The radiative rates, oscillator strengths, and line strengths are listed for all electric dipole (E1) transitions. However, for magnetic dipole (M1), electric quadrupole (E2), and magnetic quadrupole (M2) transitions, only radiative rates are listed. The importance of valence–valence (VV) and core–valence (CV) correlation effects in the calculation of energy levels have also been shown. To confirm the accuracy of the present results for energy levels by GRASP, independent calculations have been performed by using Flexible Atomic Code (FAC) and configuration interaction method (CIV3). The accuracy of the present levels, wavelengths, transition rates, and lifetimes are assessed by comparing them to available experimental and other theoretical results. We believe that our extensive results may be beneficial in fusion plasma research and astrophysical investigations and applications.


2014 ◽  
Vol 92 (6) ◽  
pp. 545-550 ◽  
Author(s):  
Kanti M. Aggarwal ◽  
Francis P. Keenan

We report calculations of energy levels and oscillator strengths for transitions in W XL, undertaken with the general-purpose relativistic atomic structure package (GRASP) and flexible atomic code (FAC). Comparisons are made with existing results and the accuracy of the data is assessed. Discrepancies with the most recent results of S. Aggarwal et al. (Can. J. Phys. 91, 394 (2013)) are up to 0.4 Ryd and up to two orders of magnitude for energy levels and oscillator strengths, respectively. Discrepancies for lifetimes are even larger, up to four orders of magnitude for some levels. Our energy levels are estimated to be accurate to better than 0.5% (i.e., 0.2 Ryd), whereas results for oscillator strengths and lifetimes should be accurate to better than 20%.


2016 ◽  
Vol 94 (9) ◽  
pp. 839-852
Author(s):  
Arun Goyal ◽  
Indu Khatri ◽  
Narendra Singh ◽  
A.K. Singh ◽  
Rinku Sharma ◽  
...  

In the present work, we provide a most extensive and detailed study of highly ionized Cu-like ions and diagnose extreme ultraviolet (EUV) and soft X-ray (SXR) transitions with N-shell electron excitation to M-shell and higher shells. We have determined energy levels and lifetimes for lowest 27 fine-structure levels by adopting multiconfiguration Dirac–Fock (MCDF) with the inclusion of quantum electrodynamics (QED) as well as Breit corrections as a first-order perturbation theory. We have also reported complete radiative data for strong electric dipole transitions within lowest 27 levels. We have compared our calculated results with theoretically calculated and experimentally measured results available in the literature, to measure the credibility and genuineness of our results, and achieve good agreement. Further, because of insufficiency of adequate and complete atomic data for higher levels of highly ionized Cu-like ions in the literature, we have performed other equivalent parallel calculations by implementing fully relativistic distorted wave flexible atomic code (FAC) to ensure the accuracy of our results. Additionally, we have also presented transition wavelengths of Nα transitions of high-Z Cu-like ions by using Moseley’s law. We believe that the large amount of atomic data presented in this paper may be useful in fusion and astrophysical plasma and in several applications, especially in lithography and cell biology.


2016 ◽  
Vol 94 (8) ◽  
pp. 712-723 ◽  
Author(s):  
Arun Goyal ◽  
Narendra Singh ◽  
Sunny Aggarwal ◽  
A.K. Singh ◽  
Man Mohan

In this work, we provide a detailed and elaborate theoretical study of atomic data along with plasma parameters for Kr XXIV. We have computed energy levels, lifetimes, and wave-function compositions for the lowest 148 fine-structure levels by implementing the multi-configuration Dirac–Fock method with the addition of quantum electrodynamics as well as Breit corrections. We have also given the radiative data among 148 levels for electric dipole (E1) transition, which lie in the extreme ultraviolet range. We have compared our calculated results with NIST and other theoretical results available in the literature and attain a good agreement. Because of the unavailability of sufficient and complete data for higher excited levels for Kr XXIV in the literature, a similar calculation has also been compiled using fully relativistic flexible atomic code (FAC) to access the credibility and integrity of our results. On the other hand, we have also presented the line intensity ratio and plasma parameters for optically thin plasma, which are not published anywhere in the literature, and we believe that our presented results may be advantageous in plasma modeling and astrophysical and fusion plasma research applications.


2014 ◽  
Vol 92 (11) ◽  
pp. 1285-1296 ◽  
Author(s):  
Sunny Aggarwal ◽  
Nupur Verma ◽  
A.K. Singh ◽  
Narendra Singh ◽  
Rinku Sharma ◽  
...  

We present accurate atomic structure calculations for the lowest 200 fine structural energy levels for oxygen-like nickel, which may be a useful ion for both astrophysical and fusion plasmas. For the calculations of energy levels and radiative rates, we have used the multiconfigurational Dirac–Fock method. Our results are compared with those obtained using other numerical methods and experiments so that their accuracy can be assessed. The transition wavelengths, oscillator strengths, and radiative rates are reported for electric dipole (E1) transitions from the ground state. We have also presented the transition probabilities and transition wavelength of some forbidden transitions. Finally, we predict new energy levels, oscillator strengths, and transition probability data, where no other theoretical or experimental results are available, which may be useful for future experimental work.


Sign in / Sign up

Export Citation Format

Share Document