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1.
The KLL dielectronic recombination processes for highly charged krypton, iodine and barium ions 下载免费PDF全文
The KLL dielectronic recombination (DR) processes of
ions from highly charged helium-like to oxygen-like krypton, iodine
and barium ions are studied systematically in the relativistic
distorted-wave approximation with configuration interaction. The KLL
DR resonant energies, the corresponding resonant strengths and the
theoretical spectra for each highly charged ion species are
obtained. The results accord well with other available values. The
behaviour of KLL resonant strengths for He-like ions with atomic
number Z is analysed. 相似文献
2.
González Martínez AJ López-Urrutia JR Braun J Brenner G Bruhns H Lapierre A Mironov V Soria Orts R Tawara H Trinczek M Ullrich J Scofield JH 《Physical review letters》2005,94(20):203201
We present experimental data on the state-selective quantum interference between different pathways of photorecombination, namely, radiative and dielectronic recombination, in the KLL resonances of highly charged mercury ions. The interference, observed for well resolved electronic states in the Heidelberg electron beam ion trap, manifests itself in the asymmetry of line shapes, characterized by "Fano factors," which have been determined with unprecedented precision, as well as their excitation energies, for several strong dielectronic resonances. 相似文献
3.
Based on the multi-configuration Dirac-Fock method, theoretical calculations are carried out for the dielectronic recombination (DR) rate coefficients and the collision excitation rate coefficients of Sn^10+ ions. It is found that the total DR rate coefficient has its maximum value between 10eV and 100eV and is greater than either the radiative recombination or three-body recombination rate coefficients (the number of free electrons per unit is 10^21 cm^3) for the ease of Te 〉 1 eV. Therefore, DR can strongly influence the ionization balance of laser produced multi-charged tin ions. The related dieleetronie satellite cannot be ignored at low temperature Te 〈 5 eV. 相似文献
4.
A.I. Magunov D. Batani A.Y. Faenov G. Lucchini T. Desai F. Padoan T.A. Pikuz I.Y. Skobelev F. Canova N. Chiodini 《Applied physics. B, Lasers and optics》2006,82(1):19-24
Radiation emission of silicon and aluminum plasmas produced by 40-ps laser pulses with peak intensity above 1014 W/cm2 was studied. High-resolution soft X-rayspectra of H-like and He-like ions were analyzed to determine plasma parameters. We
compared the line shape of resonance transitions and their intensity ratios to corresponding dielectronic satellites and the
intensities of the intercombination lines of He-like ions with the results of model calculations. Such comparisons gave average
values of the electron number density Ne=(1-1.9)×1021 cm-3 and the electron temperature Te=460–560 eV for Si plasmas and about 560 eV for Al plasmas produced by the first and the second laser harmonics. The plasma
size is about 100 μm. According to our estimations, more than 1012 photons were produced within the resonance line spectral width and in the solid angle 2π during the total decay period.
PACS 41.50.+h; 52.25.Os; 52.50.Jm 相似文献
5.
D. Batani T. Desai G. Lucchini F. Canova A. I. Magunov A. Ya. Faenov 《辐射效应与固体损伤》2013,168(10-12):507-514
High-resolution soft X-ray spectra of H-like and He-like ions were produced from laser irradiated silicon and aluminum targets. Plasma size was about 100 μm. X-ray spectra were analyzed to determine plasma parameters. We compared the line shape of resonance transitions and their intensity ratios to corresponding dielectronic satellites and the intensities of the inter combination lines of He-like ions, with the results of model calculations. Such comparison gave average values of the electron density N e=(1?1.9)×1021 cm?3 and the electron temperature T e=460–560 eV for Si plasmas and about 560 eV for Al plasmas produced by the first and the second laser harmonics. According to our estimations, more than 1012 photons were produced within the resonance line spectral width and in the solid angle 2π steredian during the total decay period. 相似文献
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A first temperature measurement of the expanded electron beam from a super-conducting magnet in the cooler of CRYRING is reported.
It is based on detection of a dielectronic recombination resonance in C2+. For this measurement C3+ was stored in the ring at 3 rm{MeV/amu} energy. A fit to the resonance with free transverse and longitudinal temperatures
gave 3.9 × 10-3 eV and 4.5 × 10-5 eV, respectively. The result is also compatible with the values of 10-3 eV for the transverse and 6.7 ×10-5 eV for the longitudinal component, in good agreement with expected values.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
8.
Effects of the nuclear charge distribution upon the total cross-section of dielectronic recombination are investigated. We calculated isotope shifts of resonance energies for H-, He- and Li-like heavy ions in the relativistic domain from Z = 54 to Z = 94. We point out that the position of the resonances is most influenced in KLL transitions in very heavy elements and their shifts are most likely to be measurable for systems with intra-shell transitions. For these systems, dielectronic recombination experiments provide a new method to determine the parameters of the nuclear charge distribution.Received: 26 July 2004, Published online: 5 October 2004PACS:
34.80.Lx Electron-ion recombination and electron attachment - 31.30.Jv Relativistic and quantum electrodynamic effects in atoms and moleculesR. chiopu: Now at Institut für Physik, Johannes-Gutenberg-Universität, Mainz, Germany. 相似文献
9.
The KLn dielectronic recombination processes of trapped highly charged B-like through He-like Cu ions are studied theoretically, and the theoretical results are used to analyse our previous experimental data at Heidelberg electron beam ion trap (EBIT). The theoretical resonant positions agree with the experimental resonant positions to a precision of 0.4%, in comparison with the resonant positions of those highest peaks between theory and experiment. The experimental spectra are then fitted using a formula with the theoretical resonant energies and strengths, the result shows good overall agreement between theory and experiment over a wide electron energy range. The distribution of highly charged states is obtained from the fitting parameters. 相似文献
10.
V.L. Jacobs J. Davis J.E. Rogerson M. Blaha 《Journal of Quantitative Spectroscopy & Radiative Transfer》1978,19(6):591-598
The results of calculations of the ionization equilibrium and radiative energy loss rates for C, N and O ions in low-density plasmas are presented for electron temperatures in the range 104–107 °K (~1–103 eV). The ionization structure is determined using the steady-state corona model, in which electron impact ionization from the ground states is balanced by direct radiative and dielectronic recombination. Using an improved theory, detailed calculations are carried out for the dielectronic recombination rates in which account is taken of all radiative and autoionization processes involving a single-electron electricdipole transition of the recombining ion. The radiative energy loss processes considered are electron-impact excitation of resonance line emission, direct radiative recombination, dielectronic recombination, and electron-ion bremsstrahlung. For all three elements, resonance line emission resulting from 2s?2p transitions produces a broad maximum in the energy loss rate near 105°K(~ 10 eV). 相似文献
11.
O. Uwira A. Müller J. Linkemann T. Bartsch C. Brandau M. Schmitt A. Wolf D. Schwalm R. Schuch W. Zong H. Lebius W.G. Graham J. Doerfert D.W. Savin 《Hyperfine Interactions》1997,108(1-3):149-154
Recombination of Au49+, Au50+, and Au51+ ions has been studied at the TSR. With Au50+ ions a storage lifetime of only 2 to 4 s was observed with the magnetically expanded electron beam of the cooler at a density
of ne = 107 cm-3. This short storage time is a consequence of the highest recombination rate coefficient ever observed with an atomic ion
(1.8·10-6 cm3 s-1 at zero relative energy Erel = 0 between electrons and ions). At about 30 meV a huge dielectronic recombination resonance is found with a record small
width of only about 15 meV. Such resonances fortuitously occurring near Erel=0 are probably the main reason for the enhanced recombination rates observed with Au50+, with Pb53+ (in a recent experiment at LEAR) as well as with other complex ions. For Au49+ and Au51+ the recombination rates are smaller by an order of magnitude.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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In this work, the KLL dielectronic recombination (DR) processes of highly charged He-like to O-like xenon ions are studied systematically by using a DR program, which is based on the multi-configuration Dirac-Fock (MCDF) method. The KLL DR resonant energies and the corresponding resonant strengths are calculated, asizing especially the effect of the Breit interaction on the DR strengths. The theoretical KLL DR spectra are obtained and compared with the latest experimental results obtained in the Shanghai Electron Beam Ion Trap. 相似文献
15.
T. Bartsch A. Müller W. Spies J. Linkemann H. Danared D.R. DeWitt H. Gao W. Zong R. Schuch A. Wolf G.H. Dunn 《Hyperfine Interactions》1998,114(1-4):251-256
The enhancement of dielectronic recombination by applied electric fields has been observed and measured for the first time
in a wide range of controlled and measurable fields using multiply charged ions. The heavy ion storage ring, CRYRING, at Stockholm
University was used to store a beam of Si11+ and collide it with a cold electron target. The observation of a substantial monotonic increase of the rate coefficient for
the group of higher Rydberg states is in puzzling disagreement with theoretical calculations of electric field enhanced dielectronic
recombination.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
16.
O. Uwira A. Müller W. Spies A. Frank J. Linkemann C. Brandau T. Cramer C. Kozhuharov J. Klabunde N. Angert P.H. Mokler R. Becker M. Kleinod N.R. Badnell 《Hyperfine Interactions》1997,108(1-3):167-175
Recombination of multiply charged ions with electrons at very low relative energies has become a major topic of interest,
due to the observation of rates which are enhanced beyond the expectations for radiative recombination. We present results
for Ar16+ and Ar18+ ions from systematic measurements along the argon isonuclear sequence using a high density cold electron beam target (ne = 7 × 109 cm-3) at the UNILAC of GSI. The transverse and longitudinal temperatures of the electron beam were determined from DR resonance
features observed with metastable Ar16+ (23S) ions. The rate at Erel = 0 for radiative recombination of completely stripped Ar18+ calculated with electron beam temperatures kT∥ = 0.002 eV, kT⊥ = 0.2 eV amounts to α = 10-9 cm3 s-1. This is exceeded by nearly a factor of 10 by the rate measured in experiments with Ar18+ ions.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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在相对论多组态Dirac-Fock理论基础上,利用近期发展的计算双电子复合截面的程序,系统研究了高离化态类氦到类硼Hg和U离子的KLL双电子复合过程. 讨论了Breit效应和量子电动力学(QED)效应对Hg离子共振双激发态能级的贡献,得到了双激发态的共振能、总线宽和相应的双电子复合共振强度,所得结果与其他理论和实验结果都符合得很好. 在此基础上进一步研究了高离化态U离子的KLL双电子复合过程,并与已有的实验和理论结果作了比较.
关键词:
双电子复合
MCDF 相似文献
19.
本文用全量子力学方法计算了Ti、Cr类He总双电子复合速率系数和态-态双电子复合速率系数,给出了Ti、Cr类He态-态双电子复合速率系数与旁观主量子数、与原子实耦合对称性,以及与谱项多重性、对称性和角动量之间的关系.计算结果显示1s2pnp→1s2np和1s2pnd→1s2nd两衰变通道的双电子复合速率系数占总双电子复合速率系数的75%,成为对总双电子复合速率系数贡献最大的两个复合通道.本文得到了能用于冕区等离子体诊断目的的Ti、Cr类 He双电子复合数据. 相似文献