Results 221 to 230 of about 73,179 (247)

Positron lifetime calculations of defects in titanium

AIP Conference Proceedings, 2019
This work uses quantum-mechanical electronic-structure calculations based on the Density Functional Theory (DFT). Investigation of empty nano-voids and vacancy clusters with different hydrogen or helium concentrations in Titanium. Mono vacancy relaxation and its impact on positron lifetime (PLT) calculation has been studied.
Kolev, B., Troev, T., Popov, E., Peneva, S.   +3 more
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Lifetime measurements and calculations in La I

The European Physical Journal D, 2004
Radiative lifetime measurements have been performed, with a time-resolved laser-induced fluorescence technique, for 20 odd-parity levels of La I belonging to the configurations 5d(2)6p, 5d6s6p and 4f5d6s. The new results are compared with the few experimental data available in the literature and with theoretical calculations including configuration ...
E. Biémont, P. Quinet, S. Svanberg, H. L. Xu   +3 more
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Calculated Lifetimes in the Neon Isoelectronic Sequence

Physica Scripta, 1979
Calculations of energies and lifetimes of levels for configurations 2s22p53l and 2s2p63l were performed for the Mg, Si, S, Ar, Ca, Ti, V, Cr, Fe, Ni ions. The intermediate coupling scheme was used. The initial energy matrix was derived in the LS-scheme. Relativistic corrections were calculated using the Breit operator.
L A Bureeva, U I Safronova
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Calculation of positron lifetimes in bulk materials

Journal of Physics: Condensed Matter, 1991
The authors have calculated positron lifetimes in different bulk materials using the LMTO (linear muffin-tin orbitals) method. Electron-positron correlation effects have been included in the calculation through the enhancement factor calculated within the local density approximation (LDA) by Jarlborg and Singh (1989). Following Jensen and Puska (1987),
B Barbiellini, P Genoud, T Jarlborg
openaire   +1 more source

Multidimensional WKB approximation and the lifetime calculation

Physical Review A, 2001
A Wentzel-Kramers-Brillouin (WKB) approach for calculating the lifetime of the ground state of two coupled oscillators with the most probable escape path along one of the coordinate axes is suggested. The WKB approximation of the wave function in the neighborhood of this path is obtained by scaling the corresponding variable.
J. Zamastil, V. Špirko, J. Čížek, L. Skála, O. Bludský   +4 more
openaire   +1 more source

The Calculation of Positron Lifetimes

1984
A recent admirable review by Drachman, 1 given on the occasion of the first conference in this series, contains a helpful section on lifetime calculations. Drachman reviews two interesting techniques for improving the accuracy of calculated lifetimes which are based not upon calculating better wave functions but rather upon operator transformations. In
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Comment on the Calculation of Neutron Lifetime

Nuclear Science and Engineering, 1969
(1969). Comment on the Calculation of Neutron Lifetime. Nuclear Science and Engineering: Vol. 38, No. 2, pp. 178-179.
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Minority Carrier Lifetime Calculation in Solar Cell

2020
This paper presents the analysis and calculation of minority carrier lifetime in silicon solar cell with different three of recombination processes: radiative recombination, Auger recombination and SRH recombination. The power conversion efficiency of solar cell is directly proportional to the minority carrier lifetime of solar cell, because of the ...
Thein Htike, Hla Myo Tun
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Comparison of methods for calculating decay lifetimes

Physical Review C, 1978
A simple scattering model is used to test alternative methods for calculating decay lifetimes, or equivalently, resonance widths. We consider the scattering of s-wave particles by a square well with a square barrier. Exact values for resonance energies and resonance widths are compared with values calculated from Wigner-Weisskopf perturbation theory ...
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WKB Approach to Calculating the Lifetime of Quasistationary States

Physical Review Letters, 2000
A novel WKB approach to calculating the lifetime of quasistationary states in the potential wells of the form V(x)=P(x)-muQ(x), where P(x) is the radial part of the potential for the spherically symmetric harmonic oscillator or the hydrogen atom and Q(x) is a polynomial, is suggested.
J, Zamastil, J, Cízek, L, Skála
openaire   +2 more sources