Lifetime studies of Ar-2p-vacancies travelling through solids

Feldman, L. C.; Silvėrman, P. J.; Fortner, R. J.

doi:10.1016/0029-554x(76)90706-0

Cited by 27 publications

(5 citation statements)

References 5 publications

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“…[9][10][11] Unfortunately, as for vacant 2pσ molecular orbitals (MOs) production, Morenzoni et al, Knudson et al, and Feldman et al argued that they originate from 2pσ -2pπ electron promotion, whether or not there are vacancies in higher-Z partner L-shell, i.e., 2pπ vacant MOs, before interactions with target atoms. [9,[12][13][14][15][16] In contrast, Winters et al and Mizogawa et al argued that the light-Z partner K-shell electrons can be directly removed to a level higher than 2p or continuum states, and then these vacancies evolve to 2pσ and share between two partners. Only if the higher-Z partners bear the L-shell vacancies, will the 2pσ -2pπ electron promotion predominate the 2pσ generation.…”

Section: Introductionmentioning

confidence: 98%

Production of projectile and targetK-vacancy in near-symmetric collisions of 60–100 MeV Cu⁹⁺ions with thin Zn target

et al. 2016

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We report studies on both target and projectile K-shell ionization by collisions of Cu 9+ ions on the thin Zn target in the energy range of 60-100 MeV. In this work, the relative ratio for the production of the target to projectile K-vacancy is measured. The result shows that it almost remains stable over this energy range and has good consistency with the predictions by vacancy transfer via the 2pσ -1sσ rotational coupling, which gives experimental evidence for K-vacancy sharing between two partners. Furthermore, the discussion for comparisons between the experimental ionization cross sections and the possible theoretical estimations is presented. These comparisons suggest that the experimental data agree well with those predicted by the Binary-Encounter approximation (BEA) model but are not in good agreement with the modified BEA calculations. It allows us to infer that the direct ionization (and/or excitation) is of importance to initial K-vacancy production before 2pσ -1sσ transitions in the present collision condition.

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Section: Introductionmentioning

confidence: 98%

Production of projectile and targetK-vacancy in near-symmetric collisions of 60–100 MeV Cu⁹⁺ions with thin Zn target

et al. 2016

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“…They also measured the 'effective' K-shell x-ray production of Al targets with varied thicknesses ranging from 0.5 to 25 µg cm −2 to study ion charge state effects for different target thicknesses. These studies stimulated interest in the charge state dependence of heavy ions as a function of target thickness [8,10,16,[18][19][20][21][22][23][24][25][26][27][28]. In the work by Betz et al [10] the rates of vacancy production, charge exchange and quenching for the projectile moving inside the solid target were included.…”

Section: Introductionmentioning

confidence: 99%

“…In the work by Betz et al [10] the rates of vacancy production, charge exchange and quenching for the projectile moving inside the solid target were included. The variation of x-ray yield with target thickness for heavy ion collisions was fitted to a 2-component model [16,20,22,24] for projectiles containing 0 and 1 K-shell vacancy and later a 3-component model [27][28][29][30] that describes fractions of projectiles with 0, 1, and 2 K-shell vacancies inside the target. If the solid target is thin enough and approximately single-collision conditions exist [23,24,30], the x-ray production cross section can be determined as a function of the projectile charge state.…”

Section: Introductionmentioning

confidence: 99%

Charge state dependence of copper L-shell x-ray production by 4 - 14 MeV oxygen ions

Azordegan

Sun

et al. 1997

J. Phys. B: At. Mol. Opt. Phys.

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Charge state dependence of L-shell x-ray production cross sections in bombarded by 4 - 14 MeV ions with charge states from q = 3+ to 8+ was measured using a Si(Li) x-ray detector with a resolution of 96 eV at 1 keV. An ultra-thin copper foil was used to ensure single-collision conditions. The data for the total L x-ray production cross sections are compared to the predictions of the first Born and the ECPSSR calculations for L-shell ionization converted to x-ray production cross sections using a single-hole fluorescence yield. Except at the lowest projectile velocity, the ECPSSR theory gives satisfactory agreement with the data while the first Born theory overpredicts all the data in the investigated energy range by almost two orders of magnitude. Measurements of the charge state dependence of the target L-shell x-ray production cross sections allowed the separate contributions of the electron capture (EC) and the direct ionization (DI) to the inner-shell ionization to be determined. The EC contributions were extracted from the x-ray measurements with two, one, and no K-shell vacancies in the oxygen ions. These EC cross sections are compared with the results of an OBK approximation and the ECPSSR theory, and found to be significantly smaller than both EC calculations.

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“…A similar model was used to determine the number of 2p vacancies of an Ar projectile impinging on aluminium targets of varying thickness [12]. If the target radiation is not detectable the probe-layer technique can be advantageous [10,13,14,17].…”

Section: Introductionmentioning

confidence: 99%

Charge-state distributions and the population of x-ray emitting states

1979

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The population of excited states of neon projectiles has been deduced from highresolution x-ray spectra. From the comparison of the satellite and the hypersatellite spectrum we conclude that the population of the outer shells is insensitive to the presence of either one or two K-shell vacancies. On the basis of a model of independent electrons the population distribution including states with filled K-shell can be estimated. The deduced mean charge states compare rather well with results obtained from beam analysis over a projectile energy range from 5 to 18 MeV.

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Lifetime studies of Ar-2p-vacancies travelling through solids

Cited by 27 publications

References 5 publications

Production of projectile and targetK-vacancy in near-symmetric collisions of 60–100 MeV Cu⁹⁺ions with thin Zn target

Production of projectile and targetK-vacancy in near-symmetric collisions of 60–100 MeV Cu⁹⁺ions with thin Zn target

Charge state dependence of copper L-shell x-ray production by 4 - 14 MeV oxygen ions

Charge-state distributions and the population of x-ray emitting states

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Lifetime studies of Ar-2p-vacancies travelling through solids

Cited by 27 publications

References 5 publications

Production of projectile and targetK-vacancy in near-symmetric collisions of 60–100 MeV Cu9+ions with thin Zn target

Production of projectile and targetK-vacancy in near-symmetric collisions of 60–100 MeV Cu9+ions with thin Zn target

Charge state dependence of copper L-shell x-ray production by 4 - 14 MeV oxygen ions

Charge-state distributions and the population of x-ray emitting states

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Production of projectile and targetK-vacancy in near-symmetric collisions of 60–100 MeV Cu⁹⁺ions with thin Zn target

Production of projectile and targetK-vacancy in near-symmetric collisions of 60–100 MeV Cu⁹⁺ions with thin Zn target