| 1. |
- Bengtsson, Peter, et al.
(författare)
-
Energy structure and transition rates in the Ne-like sequence from relativistic CI calculations
- 2012
-
Ingår i: Europhysics Conference Abstracts;36C. - : European Physical Society. ; , s. 128-128
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Atomic data are important in astrophysical applications and transition rates can be used in the determination of element abundances and plasma diagnostics. To provide for the extensive data needs a number of general computer codes such as SUPERSTRUCTURE, CIV3, and ATSP2K have been developed. As an alternative to these codes, which all rely on the Breit-Pauli approximation, the fully relativistic GRASP2K code can be used. GRASP2K is based on the multiconfiguration Dirac-Hartree-Fock method and implements a bi-orthogonal transformation method that permits initial and final states in a transition array to be optimized separately, which, in many cases, leads to more accurate values of the resulting rates. The GRASP2K package also contains modules to compute diagonal and off-diagonal hyperfine interaction constants, isotope shifts, Land´e gJ factors, and splittings of magnetic sub-state in intermediate and strong magnetic fields. In this work, GRASP2K has been applied to provide highly accurate spectroscopic data for ions in the Ne-like sequence between Mg III and Kr XXVII. Valence, core-valence, and core-core correlation effects were accounted for through SD-MR expansions to increasing sets of active orbitals. In Mg III, Al IV, Si V, P VI, S VII, and Ar IX, for which experimental energies are known to high accuracy, the mean error in the calculated energies is only 0.011%. For ions with no available experimental energy levels the calculated values should be most valuable in various applications. The high accuracy of the calculated energies makes it possible, in some cases, to to point out experimental values that are in error. Babushkin (length) and Coulomb (velocity) forms of transition rates are computed and agree to within a few percent for the majority of the allowed transitions. Computed lifetimes for states belonging to the 2p33s and 2p53d configurations are in good agreement with values from beam-foil measurements as well as from accurate MCHF Breit-Pauli calculations.
|
|
| 2. |
- Ekman, Jörgen, et al.
(författare)
-
A spectral study of Te V from MCDHF calculations
- 2013
-
Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 46:9
-
Tidskriftsartikel (refereegranskat)abstract
- State-of-the-art multiconfiguration Dirac-Hartree-Fock calculations for Te V have been performed and energies, LS-compositions, radiative lifetimes and Lande gJ-factors for 51 odd and even parity states are presented. In addition, predictions on transition rates and oscillator strengths for a multitude of transitions between these states are reported for the first time. To describe the atomic system accurately, by means of configuration interaction, valence and core-valence electron correlation effects were taken into account. Calculated energies and lifetimes of excited states agree very well with experimental data.
|
|
| 3. |
- Ekman, Jörgen, et al.
(författare)
-
Calculations with spectroscopic accuracy : energies, transition rates, and Landé g_J-factors in the carbon isoelectronic sequence from Ar XIII to Zn XXV
- 2014
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 564
-
Tidskriftsartikel (refereegranskat)abstract
- Extensive self-consistent multiconfiguration Dirac-Hartree-Fock (MCDHF) calculations and subsequent relativistic configuration in- teraction calculations are performed for 262 states belonging to the 15 configurations 2s22p2, 2s2p3, 2p4, 2s22p3l, 2s2p23l, 2p33l and 2s22p4l (l = 0,1,2) in selected carbon-like ions from Ar XIII to Zn XXV. Electron correlation effects are accounted for through large configuration state function expansions. Calculated energy levels are compared with existing theoretical calculations and data from the Chianti and NIST databases. In addition, Landé gJ -factors and radiative electric dipole transition rates are given for all ions. The accuracy of the calculations are high enough to facilitate the identification of observed spectral lines.
|
|
| 4. |
|
|
| 5. |
- Ekman, Jörgen, et al.
(författare)
-
Validation and Implementation of Uncertainty Estimates of Calculated Transition Rates
- 2014
-
Ingår i: Atoms. - : MDPI. - 2218-2004. ; 2:2, s. 215-224
-
Forskningsöversikt (refereegranskat)abstract
- Uncertainties of calculated transition rates in LS-allowed electric dipole transitions in boron-like O IV and carbon-like Fe XXI are estimated using an approach in which differences in line strengths calculated in length and velocity gauges are utilized. Estimated uncertainties are compared and validated against several high-quality theoretical data sets in O IV, and implemented in large scale calculations in Fe XXI.
|
|
| 6. |
- Fors, Andreas, 1977, et al.
(författare)
-
Person-centred e-health in patients with coronary heart disease
- 2013
-
Ingår i: Sixth Geneva conference on person-centered medicine. April 29 – May 1, 2013.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Background Remote monitoring of patients with coronary heart disease (CHD) has yielded mixed and often disappointing results [1]. One reason could be that remote monitoring mirrors a disease focused of looking at the patient [2], hence only promoting a one-way communication between the patient and health care professionals. Purpose To investigate the feasibility and effect of an e-health application aimed for self-monitoring of signs and symptoms in patients with CHD. Design This study is part of an ongoing randomized controlled trial in Sweden for patients with CHD. Patients are trained at the hospital to use a smartphone application and a web-site for the following 12 months where they are able to 1) write a health diary 2) rate their current state of fatigue, motivation and concentration 3) obtain daily trend graphs of physical activity, measured via a built-in accelerometer 4) establish chat-contact with other patients in the study 5) establish contact with staff at e.g. their study clinic. Expected results To our knowledge, this is the first study that will evaluate a combined smartphone and web-based person-centred diary for patients with CHD. Tentative findings indicate a feasibility of a smartphone application for patients. Further findings will be presented at the conference. References 1. Anker, S.D., F. Koehler, and W.T. Abraham. Telemedicine and remote management of patients with heart failure. Lancet, 2011. 378(9792): p. 731-9. 2. Swedberg, K., A. Wolf, and I. Ekman. Telemonitoring in patients with heart failure. New England Journal of Medicine, 2011. 364(11): p. 1078; author reply 1079-80.
|
|
| 7. |
- Gellanki, Jnaneswari, et al.
(författare)
-
Extensive Gamma-ray Spectroscopy of Band Structures in 62Zn
- 2012
-
Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 86:3
-
Tidskriftsartikel (refereegranskat)abstract
- An experimental study of the Zn-62 nucleus has been performed by combining the data sets from four fusion-evaporation reaction experiments. Apart from the previously published data, the present results include ten new rotational band structures and two more superdeformed bands. The Gammasphere Ge-detector array in conjunction with the 4 pi charged-particle detector array Microball allowed for the detection of gamma rays in coincidence with evaporated light particles. The deduced level scheme includes some 260 excited states, which are connected with more than 450 gamma-ray transitions. Spins and parities of the excited states have been determined via directional correlations of. rays emitted from oriented states. The experimental characteristics of the rotational bands are analyzed and compared with results from cranked Nilsson-Strutinsky calculations. The present analysis, combined with available experimental results in the A similar to 60 mass region, can be used to improve the current set of Nilsson parameters in the N = 3 and N = 4 oscillator shells.
|
|
| 8. |
- Gellanki, Jnaneswari, et al.
(författare)
-
High-spin Structure Studies in 62Zn
- 2012
-
Ingår i: Physica Scripta. - 0031-8949. ; T150
-
Tidskriftsartikel (refereegranskat)abstract
- A detailed experimental study of the Zn-62 nucleus was conducted by combining the data sets from four fusion-evaporation reaction experiments. Apart from the previous published data, the present results include ten new rotational band structures and two new superdeformed bands. The GAMMASPHERE Ge-detector array in conjunction with the 4 pi charged-particle detector array Microball allowed for detection of gamma-rays in coincidence with evaporated light particles. The deduced level scheme includes some 260 excited states, which are connected with 450 gamma-ray transitions. The multipolarities have been assigned via directional correlations of gamma-rays emitted from oriented states. The experimental characteristics of the rotational bands are analyzed and compared with the results from the cranked Nilsson-Strutinsky calculations.
|
|
| 9. |
- Grumer, Jon, et al.
(författare)
-
Atomic Data and Stark Broadening Parameters for Sn II and Sn III
- 2013
-
Ingår i: Book of abstracts. - : Institute of Modern Physics, Chinese Academy of Sciences.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Synopsis Extensive multicon guration Dirac-Hartree-Fock (MCDHF) and relativistic con guration interaction (RCI) calculations of energies, transition rates and broadening parameters are reported for Sn II and Sn III, ions which are of importance for plasma modeling. Results are compared with other recent works.
|
|
| 10. |
- Jönsson, Per, et al.
(författare)
-
Atomic Structure Calculations with Spectroscopic Accuracy : Implications for Laboratory Work
- 2014
-
Ingår i: Ninth International Conference on Atomic and Molecular Data and Their Applications: book of abstracts. ; , s. 112-112
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The observation of atomic spectra constitutes an important tool for diagnostics of astrophysical plasmas, and there is a boom of activity involving several new and planned multibillion-dollar telescopes. However, to correctly interpret observed spectra, the atomic lines must be known and identified from laboratory work. Laboratory work is hard and time-consuming, and present efforts do not in any way match the needs for data, partly due to lack of funding [1] and partly due to experimental limitations. One goal of atomic structure calculations is to provide energy differences with ”spectroscopic accuracy” to aid laboratory work. Using highly accurate calculated energy differences it should be possible to directly validate or rule out experimental energy level and line identifications. New and efficient methods for solving the Dirac-equation for many electron systems, together with today’s fast computers, indeed make it possible to perform calculations with spectroscopic accuracy for ions of medium complexity. We give a number of examples of calculations based on the relativistic configuration interaction (RCI) method in B-, C-, N-, O-, and Ne-like systems, where energies levels far up in the spectrum have been predicted with uncertainties of 0.05 % or less [2,3,4]. Depending on the spectral range, these uncertainties are in many cases close to what can be experimentally obtained. The above mentioned calculations reveal that many experimental energy levels given in the literature and in data bases are wrong and based on misidentifications. We finally show how the accuracy of atomic structure calculations can be further improved, and results extended to more complex systems, by using the novel partitioned configuration function interaction (PCFI) method [5]. Some practical consequences of the recent advances in computational methodology for laboratory work are discussed.
|
|
