Charge-state correlated cross sections for the production of low-velocity highly charged Ne ions by heavy-ion bombardment

Gray, Tom J.; Cocke, C. L.; Justiniano, E.

doi:10.1103/physreva.22.849

Cited by 134 publications

(19 citation statements)

References 10 publications

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“…6). Because for q =9 double autoionizing transitions are not possible, a(n, n-2, q+4) in (6) has to be replaced by ~(n, n-2, q+3). Correcting this we get agreement with the model calculations for this charge state, too (dashed line).…”

Section: Pg(b) = Pl(o) Exp ( --B/re)mentioning

confidence: 99%

The contribution ofK-electron capture for the production of highly charged Ne recoil ions by 156 MeV bromine impact

et al. 1984

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Section: Pg(b) = Pl(o) Exp ( --B/re)mentioning

confidence: 99%

The contribution ofK-electron capture for the production of highly charged Ne recoil ions by 156 MeV bromine impact

et al. 1984

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“…In order to obtain the true yield of the recoil ions exclusively for the electron capture and for the loss processes, it is necessary to remove the unwanted contribution from the beam impurity ions. In the present case, this was done by normalizing the electron capture spectra with the direct ionization spectrum for Si ½½· ions incident on argon following the procedure of Gray et al [2]. It was noted that for the recoil ions of lower charge states (for example, for Ar · to Ar ¿· ), the corrections in the recoil ion yields after normalization ranged from 30% to almost 100%.…”

Section: Methodsmentioning

confidence: 99%

“…Additionally, applications of the cross-sections to astrophysical problems are well known. Over the years, a number of groups [2][3][4][5][6] have focused on studies of the recoil ion distributions in correlation with the scattered projectile of a given charge state. The projectile ion-recoil ion coincidence technique has been used to see the variation of the charge state distribution of the recoil ions and their partial ionization cross-sections for different ionization channels, like; direct ionization, electron capture and electron loss.…”

Section: Introductionmentioning

confidence: 99%

Multiple ionization of argon in coincidence with projectile ions in 60–120 MeV Si q+-Ar collisions

et al. 1999

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A projectile ion-recoil ion coincidence technique has been employed to study the multiple ionization and the charge transfer processes in collisions of 60-120 MeV Si Õ· (Õ -½ ) ions with neutral argon atoms. The relative contribution of different ionization channels, namely; direct ionization, electron capture and electron loss leading to the production of slow moving multiply charged argon recoil ions have been investigated. The data reported on the present collision system result from a direct measurement in the considered impact energy for the first time. The total ionization cross-sections for the recoil ions are shown to scale as Õ ½ / ¼ Ô , where Ô is the energy in MeV of the projectile and Õ its charge state.The recoil fractions for the cases of total-and direct ionizations are found to decrease with increasing recoil charge state . The total ionization fractions of the recoils are seen to depend on Õ and to show the presence of a 'shell-effect' of the target. Further, the fractions are found to vary as ½ ¾ upto · . The average recoil charge state increases slowly with Õ and with the number of lost or captured electrons from or into the projectile respectively. The projectile charge changing cross-sections Õ Õ ¼ are found to decrease with increasing Õ for loss ionization and to increase with Õ for direct-and capture ionization processes respectively. The physics behind various scaling rules that are found to follow our data for different ionization processes is reviewed and discussed.

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“…Charge state correlated cross sections were available since 1980 [2] and usually analyzed by forming products of independently obtained single-particle capture and ionization probabilities [13]. The separation of the contributions to recoil production into direct MI, single capture and MI, double capture and MI provides a much more stringent test for theory.…”

Section: Classical Lrajectory Methodsmentioning

confidence: 99%

“…In the early work only the recoil ions were detected [2] (recoil ion production cross sections) while a coincidence count of projectile ions with known charge state with the recoils yields charge state correlated cross sections [3]. Most theories dealing with this problem do not rely on a quantum mechanical (QM) description, but on semiclassicat or classical approximations.…”

Section: Pi+ + T -+ P(i-m)+ "C T Q+ -}" No-mentioning

confidence: 99%

Theory of multiple ionization and capture in energetic ion-atom collisions

Horbatsch

1991

Z Phys D - Atoms, Molecules and Clusters

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A b s t r a c tThis short review includes classical, semiclassica] and quantal methods. Information about charge state population as a function of scattering angle and about the distribution of ionized electrons in energy and solid angle can be extracted for projectile energies in the range of 50 keV/amu up to 1 GeV/amu. I n t r o d u c t i o nThe subject of this review concerns many electron processes in heavy ion collisions, mainly capture and multiple ionization (MI). We discuss the following problem: a bare nucleus of charge i impinges on a neutral target atom with N electrons and produces a q-fold charged recoil ion by capturing m and ionizing n electrons:In the early work only the recoil ions were detected [2] (recoil ion production cross sections) while a coincidence count of projectile ions with known charge state with the recoils yields charge state correlated cross sections [3]. Most theories dealing with this problem do not rely on a quantum mechanical (QM) description, but on semiclassicat or classical approximations. This works well for the prediction of the population of charge states on projectile and target after the collision and for information differential in projectile (and target) scattering angle and for electron emission spectra. Detailed QM information, such as quasiresonant K-K shell exchange can be obtained in density functional theory (DFT). The problem of N electrons and the two colliding nuclei is usually reduced to an explicitly time dependent (TD) N -b o d y problem with a fixed nuclear trajectory. This elimination of two degrees of freedom is convenient as long as one is interested in total charge state production cross sections. For information differential in the projectile or target scattering angle it poses a problem insofar as the information about deflection is contained in the phase of the nuclear scattering wave function. A further common simplification is to reduce the remaining explicitly TD many body problem to an independent particle model (IPM), such as e.g. the TD ttartree-Fock approximation or simplifications thereof. For many purposes it is sufficient to further simplify and give up on shell structure. At this level the model becomes statistical in nature, is based on the h = 0 limit and is related either to the TD Thomas-Fermi or the Vtasov model. To regain QM information it is possible to use the mean field potential from such a calculation in an effective single-particle TD SehrSdinger equation (SE), which amounts to a DFT approach.Three other approaches that do not rely on this 'standard' sequence of approximation have been applied: (i) an IPM based on perturbative expansions from stationary scattering theory, (ii) classical N+2-body calculations, and (iii) purely statistical models (energy deposition model) which do not attempt to follow the detailed evolution of the collision [1]. This review does not contain material about heavy ion collisions at low energies, where highly charged recoil ions are predominantly produced by capture. Theory 2.I S1ationary scatte...

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Charge-state correlated cross sections for the production of low-velocity highly charged Ne ions by heavy-ion bombardment

Cited by 134 publications

References 10 publications

The contribution ofK-electron capture for the production of highly charged Ne recoil ions by 156 MeV bromine impact

The contribution ofK-electron capture for the production of highly charged Ne recoil ions by 156 MeV bromine impact

Multiple ionization of argon in coincidence with projectile ions in 60–120 MeV Si q+-Ar collisions

Theory of multiple ionization and capture in energetic ion-atom collisions

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