Photoionization cross sections of H2+ and H2with complex Gaussian-type basis functions optimized for the frequency-dependent polarizabilities

2008 ◽  
Vol 29 (14) ◽  
pp. 2471-2478 ◽  
Author(s):  
Masato Morita ◽  
Satoshi Yabushita
Keyword(s):  
Cross Sections ◽  
Basis Functions ◽  
Frequency Dependent ◽  
Gaussian Type

scholarly journals 2-D reconstruction of atmospheric concentration peaks from horizontal long path DOAS tomographic measurements: parametrisation and geometry within a discrete approach

2006 ◽  
Vol 6 (3) ◽  
pp. 847-861 ◽  
Author(s):  
A. Hartl ◽  
B. C. Song ◽  
I. Pundt
Keyword(s):  
Cross Sections ◽  
Measurement Errors ◽  
Concentration Field ◽  
Basis Functions ◽  
Linear Functions ◽  
Background Concentration ◽  
Atmospheric Concentration ◽  
Piecewise Constant ◽  
Reconstruction Quality ◽  
Norm Principle

Abstract. In this study, we theoretically investigate the reconstruction of 2-D cross sections through Gaussian concentration distributions, e.g. emission plumes, from long path DOAS measurements along a limited number of light paths. This is done systematically with respect to the extension of the up to four peaks and for six different measurement setups with 2-4 telescopes and 36 light paths each. We distinguish between cases with and without additional background concentrations. Our approach parametrises the unknown distribution by local piecewise constant or linear functions on a regular grid and solves the resulting discrete, linear system by a least squares minimum norm principle. We show that the linear parametrisation not only allows better representation of the distributions in terms of discretisation errors, but also better inversion of the system. We calculate area integrals of the concentration field (i.e. total emissions rates for non-vanishing perpendicular wind speed components) and show that reconstruction errors and reconstructed area integrals within the peaks for narrow distributions crucially depend on the resolution of the reconstruction grid. A recently suggested grid translation method for the piecewise constant basis functions, combining reconstructions from several shifted grids, is modified for the linear basis functions and proven to reduce overall reconstruction errors, but not the uncertainty of concentration integrals. We suggest a procedure to subtract additional background concentration fields before inversion. We find large differences in reconstruction quality between the geometries and conclude that, in general, for a constant number of light paths increasing the number of telescopes leads to better reconstruction results. It appears that geometries that give better results for negligible measurement errors and parts of the geometry that are better resolved are also less sensitive to increasing measurement errors.

COUPLED-CHANNELS ANALYSES OF 6He BREAKUP REACTIONS

2009 ◽  
Vol 24 (11) ◽  
pp. 2191-2197 ◽  
Author(s):  
T. MATSUMOTO ◽  
T. EGAMI ◽  
K. OGATA ◽  
Y. ISERI ◽  
M. KAMIMURA ◽  
...  
Keyword(s):  
Cross Sections ◽  
Reaction System ◽  
Basis Functions ◽  
Coulomb Breakup ◽  
Body Model ◽  
Coupled Channels ◽  
Gaussian Basis Functions ◽  
Three Body ◽  
Good Agreement ◽  
The Continuum

We present analyses of breakup effects of 6 He on the elastic scattering by the continuum-discretized coupled-channels method, in which the reaction system is described as a four-body model, n+n+4 He +target. In this analysis, three-body breakup continuum of 6 He is discretized by daiagonalizing the internal Hamiltonian of 6 He in a space spanned by the Gaussian basis functions. The calculated elastic cross sections are in good agreement with the experimental data, which shows that nuclear and Coulomb breakup effects are significant.

PHOTOEMISSION CALCULATION WITH A SIMPLE MODEL FOR THE PHOTON FIELD: APPLICATION TO ALUMINIUM

1991 ◽  
Vol 05 (01) ◽  
pp. 65-72 ◽  
Author(s):  
P. DAS ◽  
R.K. THAPA ◽  
N. KAR
Keyword(s):  
Experimental Data ◽  
Simple Model ◽  
Fermi Level ◽  
Dielectric Function ◽  
Cross Sections ◽  
Free Electron ◽  
Surface Region ◽  
Field Application ◽  
Frequency Dependent ◽  
Photon Field

Photoemission cross-sections are calculated, using a simple “local” dielectric function for computing the photon field in the surface region and free electron wavefunctions. Comparisons are made with the experimental data for the frequency-dependent normal photoemission from the Fermi level of aluminium, and the importance of the variation of the photon field in the surface region is pointed out.

Periodic Oscillations of the Frequency-Dependent Photoelectric Cross Sections of Surface States: Theory and Experiment

1980 ◽  
Vol 44 (8) ◽  
pp. 549-553 ◽  
Author(s):  
Steven G. Louie ◽  
P. Thiry ◽  
R. Pinchaux ◽  
Y. Pétroff ◽  
D. Chandesris ◽  
...  
Keyword(s):  
Cross Sections ◽  
Surface States ◽  
Periodic Oscillations ◽  
Frequency Dependent ◽  
Theory And Experiment

Contracted Gaussian-type basis functions revisited. IV. Atoms Rb to Xe

2002 ◽  
Vol 108 (1) ◽  
pp. 41-45 ◽  
Author(s):  
Toshikatsu Koga ◽  
Shigeyoshi Yamamoto ◽  
Tsuyoshi Shimazaki ◽  
Hiroshi Tatewaki
Keyword(s):  
Basis Functions ◽  
Gaussian Type
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