scholarly journals Dielectronic Recombination of Highly Stripped Argon Ions: Theoretical Calculations and Direct Observations in an Ebis Source

1984 ◽  
Vol 86 ◽  
pp. 262-264
Author(s):  
M. Loulergue ◽  
J. Dubau ◽  
J.P. Briand ◽  
P. Charles ◽  
H. Laurent

The dielectronic recombination is one of the most important atomic processes in highly ionised plasmas. It corresponds to the simultaneous capture of a free electron and excitation of an ion, i.e.It is a collisionally resonant process which occurs only at the energy of the corresponding autoionisation electron. We present here a preliminary theoretical analysis of the results of an experiment using a novel technique in which it is possible to observe the interaction of a given ion with an electron at a given energy and so to measure the differential dielectronic cross section corresponding to each resonant level of this ion.

1988 ◽  
Vol 102 ◽  
pp. 71-73
Author(s):  
E. Jannitti ◽  
P. Nicolosi ◽  
G. Tondello

AbstractThe photoabsorption spectra of the carbon ions have been obtained by using two laser-produced plasmas. The photoionization cross-section of the CV has been absolutely measured and the value at threshold, σ=(4.7±0.5) × 10−19cm2, as well as its behaviour at higher energies agrees quite well with the theoretical calculations.


2014 ◽  
Vol 1061-1062 ◽  
pp. 431-435
Author(s):  
Xiao He

An actual case of PTH fracture after soldering process was studied. By means of cross section analysis using metallography microscope and SEM, together with thermal analysis results, root cause of PTH fracture was concluded that a high density of twin copper weakened the mechanical strength so seriously that PTHs could not undergo thermal stress from soldering process, and higher CTE was attributed to an accelerative factor. Moreover, it is recommended to enhance current density properly and make sure the effectiveness of electroplating additives to prevent twin copper by theoretical analysis.


2007 ◽  
Vol 121-123 ◽  
pp. 1089-1092 ◽  
Author(s):  
Jian Zhong Fu ◽  
Xiao Bing Mi ◽  
Yong He ◽  
Zi Chen Chen

Theoretical analysis of the ionized fluid flowing through a cone-shaped nanopore is presented. The internal cross section of the cone-shaped channel is in the range from micro- to nanometer and gradual change from larger to smaller than the Debye length for the ions. The model is developed to predict the ionized fluid flow behaviors in cone-shaped micro/nanochannels. The velocity profiles of ion flow that occur in nanopores are obtained.


The first section of this paper is an account of some experiments on the absorption of light in sodium vapour from the series limit at 2412 Å to about 1600 Å (an energy difference of 2·6 eV). The absorption cross-section at the limit is 11·6 ± 1·2 x 10 -20 cm 2 . The cross-section decreases giving a minimum of 1·3 ± 0·6 x 10 -20 cm 2 at 1900 Å and then increases to 1600 Å. A theoretical calculation by Seaton based on the dipole-length formula gives good agreement with the experiments at the series limit and also correctly predicts the wave-length for the minimum, but it predicts a significantly lower absorption at the minimum. The experiments described in the first section of the paper conclude a series on the absorption of light in the alkali metals. The second section consists of a general discussion of the results of these experiments and of their relation to theoretical calculations. There is good agreement between theory and experiment except in regard to the magnitude of the absorption at the minimum.


1983 ◽  
Vol 50 (5) ◽  
pp. 339-342 ◽  
Author(s):  
D. S. Belic ◽  
Gordon H. Dunn ◽  
T. J. Morgan ◽  
D. W. Mueller ◽  
C. Timmer

2014 ◽  
Vol 35 ◽  
pp. 1460397
Author(s):  
BASTIAN KUBIS

The process γπ → ππ, in the limit of vanishing photon and pion energies, is determined by the chiral anomaly. This reaction can be investigated experimentally using Primakoff reactions, as currently done at COMPASS. We derive a dispersive representation that allows one to extract the chiral anomaly from cross-section measurements up to 1 GeV, where effects of the ρ resonance are included model-independently via the ππ P-wave phase shift. We discuss how this amplitude serves as an important input to a dispersion-theoretical analysis of the π0 transition form factor, which in turn is a vital ingredient to the hadronic light-by-light contribution to the anomalous magnetic moment of the muon.


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