Excitation Of Cu Research Articles

Thermal spike model of defect production by electron excitation in Cu

The thermal spike model is investigated theoretically in order to clarify the mechanism of defect production by electron excitation in Cu [Iwase et al., J. Phys. Soc. Jpn 61 (1992) 3878]. The electron temperature and the lattice temperature are calculated numerically solving the heat-flow equation. It is clarified that the maximum lattice temperature is about 100 K when the electronic stopping power of the incident ion is 100 keV/nm and the initial lattice temperature is 10 K. This means that no defect is created by purely thermal processes induced by electron excitation in the case of Cu.

Defect Production by Electron Excitation in Cu and Ag

It has been found in ion-irradiated Cu and Ag thin foils that lattice defects are produced not only through elastic collisions, but also through a process strongly associated with electronic stopping power S e . In the latter process, the defect production cross section is proportional to S e 1.7 in Cu and S e 1.5 in Ag. The nearly quadratic dependence of the defect production cross section on S e suggests that the mutual Coulomb repulsion of ions positively charged by electron excitation causes the defect production in Cu and Ag.

Electron-impact excitation of atomic copper.

Cross sections are calculated for excitation of Cu for elastic scattering of electrons from the 4s ground state and for excitation to excited states 3d/sup 9/4s/sup 2/, 4p, and 4d. A three-state close-coupling approximation is used for the energy range 3.8 < E < 10 eV, and a four-state one for 6 < E < 100 eV. Accurate target functions are used in the expansion. Poor agreement is obtained with renormalized experimental data of Trajmar et al.

New Experimental Investigations of the Density Effect on Inner-Shell Excitation and Energy Loss

The large spread in $\ensuremath{\gamma}$ values (${1\ensuremath{-}10}^{5}$) for gigaelectronvolt secondary beams has been used in a novel technique to measure the relativistic effects on inner-shell excitation in Cu and Al and energy loss in Si and Ge. In $K$-shell excitation, a pronounced influence of density effect is found for the first time, in apparent contradiction to earlier measurements, where the lack of density effects has been a great mystery. These problems are explained as target-thickness effects in connection with transition radiation.

Photoluminescence, lifetimes, and discharge excitation of Cu 2

Photoluminescence, lifetimes, and discharge excitation of Cu 2

Jet-Controlled Arc: I, Excitation of Second Spectra

A new spectroscopic light source, which is essentially an enclosed dc arc with annular jets of gas sweeping past each electrode, is described. The composition and pressure of the carrier gas of this source can be chosen so that the character of the spectra obtained range from similarity to open-arc spectra to Schuler-lamp spectra. The effects of source conditions on the excitation of Cu i and Cu ii spectra are discussed. Spectrograms are included which illustrate the usefulness of a stigmatic image in differentiating between atomic and ionic spectral lines.

Core excitations in Cu 63

Experimental results on Cu/sup 63/ are compared with the predictions of three models that have been proposed to explain the properties of the low lying levels in odd-A