This paper calculates the electron impact excitation rate coefficients from the ground term 2s22p2 3P to the excited terms of the 2s22p2, 2s2p3, 2s22p3s, 2s22p3p, and 2s22p3d configurations of N II. In the calculations, multiconfiguration Dirac-Fork wave functions have been applied to describe the target-ion states and relativistic distorted-wave calculation has been performed to generate fine-structure collision strengths. The collision strengths are then averaged over a Maxwellian distribution of electron velocities in order to generate the effective collision strengths. The calculated rate coefficients are compared with available experimental and theoretical data, and some good agreements are found for the outer shell electron excitations. But for the inner shell electron excitations there are still some differences between the present calculations and available experiments.
The multi-configuration Dirac-Fock(MCDF) method is implemented to study doubly excited 2s2p ^(1,3)P_1 resonances of the helium atom and the interference between photoionization and photoexcitation autoionization processes.In order to reproduce the total photoionization sprectra,the excited energies from the ground 1s^2 ~1S_0 state to the doubly excited 2s2p ^(1,3)P_1 states and the relevant Auger decay rates and widths are calculated in detail.Furthermore,the interference profile determined by the so-called Fano parameters q and ρ~2 is also reproduced.Good agreement is found between the present results and other available theoretical and experimental results.This indeed shows a promising way to investigate the Fano resonances in photoionization of atoms within the MCDF scheme,although there are some discrepancies in the present calculations of the 2s2p ~3P_1 state.
In this paper, the capabilities of laser-induced breakdown spectroscopy (LIBS) forrapid analysis to multi-component plant axe illustrated using a 1064 nm laser focused onto thesurface of folium lycii. Based on homogeneous plasma assumption, nine of essential micronutrientsin folium lycii are identified. Using Saha equation and Boltzmann plot method electron densityand plasma temperature are obtained, and their relative concentration (Ca, Mg, Al, Si, Ti, Na,K, Li, and Sr) are obtained employing a semi-quantitative method.
