J/A+A/600/A85 He-like ions (Z=20-42) effective collision strengths (Si+, 2017) ================================================================================ Electron impact excitation for He-like ions with Z = 20 - 42. Si R., Li S., Wang K., Guo X.L., Chen Z.B., Yan J., Chen C.Y., Brage T., Zou Y.M. =2017A&A...600A..85S (SIMBAD/NED BibCode) ================================================================================ ADC_Keywords: Atomic physics Keywords: atomic data, atomic processes Abstract: Spectral lines of He-like ions are among the most prominent features in X-ray spectra from a large variety of astrophysical and high-temperature fusion plasmas. A reliable plasma modeling and interpretation of the spectra require a large amount of accurate atomic data related to various physical processes. In this paper, we focus on the electron-impact excitation (EIE) process. We adopted the independent process and isolated resonances approximation using distorted waves (IPIRDW). Resonant stabilizing transitions and decays to lower-lying autoionizing levels from the resonances are included as radiative damping. To verify the applicability of the IPIRDW approximation, an independent Dirac R-matrix calculation was also performed. The two sets of results show excellent agreement. We report electron impact excitation collision strengths for transitions among the lowest 49 levels of the 1snl(n<=5,l<=(n-1)) configurations in He-like ions with 20<=Z<=42. The line ratios R and G are calculated for Fe XXV and Kr XXXV. Description: Transition energy differences, transition rates and effective collision strengths for transitions of He-like ions with Z = 20 - 42. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 152 26835 Effective collision strengths -------------------------------------------------------------------------------- See also: J/A+A/592/A135 : SiXIII and SXV collision strengths (Fernandez-Menchero+, 2016) Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 2 I2 --- Z Atomic number 5- 6 I2 --- i Lower level index 9- 17 A9 --- Leveli Lower level identification, n ^S^L_J_ == 1snl ^S^L_J_ 20- 21 I2 --- j Upper level index 24- 32 A9 --- Levelj Upper level identification, n ^S^L_J_ == 1snl ^S^L_J_ 35- 44 E10.4 eV DeltaE Transition energy difference 46- 53 E8.2 s-1 Aji ? Sum of E1, M1, E2, and M2 transition rates for transition i-j 55- 62 E8.2 --- ECS1k Effective collision strengths for transition i-j at electron temperature of (Z-1)^2^*10^3^K 64- 71 E8.2 --- ECS2k Effective collision strengths for transition i-j at electron temperature of (Z-1)^2^*2*10^3^K 73- 80 E8.2 --- ECS5k Effective collision strengths for transition i-j at electron temperature of (Z-1)^2^*5*10^3^K 82- 89 E8.2 --- ECS10k Effective collision strengths for transition i-j at electron temperature of (Z-1)^2^*10^4^K 91- 98 E8.2 --- ECS20k Effective collision strengths for transition i-j at electron temperature of (Z-1)^2^*2*10^4^K 100-107 E8.2 --- ECS50k Effective collision strengths for transition i-j at electron temperature of (Z-1)^2^*5*10^4^K 109-116 E8.2 --- ECS100k Effective collision strengths for transition i-j at electron temperature of (Z-1)^2^*10^5^K 118-125 E8.2 --- ECS200k Effective collision strengths for transition i-j at electron temperature of (Z-1)^2^*2*10^5^K 127-134 E8.2 --- ECS500k Effective collision strengths for transition i-j at electron temperature of (Z-1)^2^*5*10^5^K 136-143 E8.2 --- ECS1000k Effective collision strengths for transition i-j at electron temperature of (Z-1)^2^*10^6^K 145-152 E8.2 --- ECS2000k Effective collision strengths for transition i-j at electron temperature of (Z-1)^2^*2*10^6^K -------------------------------------------------------------------------------- Acknowledgements: Ran Si, rsi13(at)fudan.edu.cn ================================================================================ (End) Patricia Vannier [CDS] 13-Jan-2017