A. M. Costa

Age-related migration patterns in Larus fuscus spp.

Migration is a critical period in a bird’s life that can affect the fitness of individuals. Intra-population migratory patterns and the way different sex and/or age classes within a population differ in timing and/or distance of migration are not completely understood. The present study aims to observe inter- and intra-population migratory patterns in the western population of Lesser Black-backed Gulls (Larus fuscus spp.), shedding light on age-related differences of temporal patterns of occurrence in the Portuguese coastal areas during migration and winter. One thousand seven hundred and fifty-four colour ring records were analysed matching a 30-year period of observations on the Portuguese coast between 1975 and 2005. During migration, the graellsii population represents 90% of the migratory flow of L. fuscus through Portugal with the intermedius accounting for 9% and the fuscus population, being vestigial in this period, accounting for 1%. Nevertheless, interesting significant differences were observed between the age classes of the three populations during this period, the graellsii population having a large number of first winters (40% of the migratory contingent of this population) followed by immatures and adults whilst in the intermedius and fuscus populations, the largest age class is the adults. During winter, no inter-population differences were found. When comparing migration and winter periods, intra-population differences were found in the graellsii and fuscus populations regarding distribution and age classes. These results indicate different migratory routes amongst different populations suggesting a leapfrog migration in L. fuscus and also a differential age-related migration pattern that might result from first winters migrating further south in search of a wintering place since adults heavily occupy the closest wintering quarters in their attempt to arrive earlier at their breeding ground.

Interpretation of x-ray spectra emitted by Ar ions in an electron-cyclotron resonance ion source

We examine the most important processes leading to the creation of excited states from the ground configurations of Ar8+ to Ar16+ ions in an electron-cyclotron resonance ion source, which lead to the emission of K x-ray lines. Theoretical values for inner-shell excitation and ionization cross sections, including double KL ionization, transition probabilities and energies for the de-excitation processes, are calculated in the framework of the multi-configuration Dirac-Fock method. With reasonable assumptions about the electron energy distribution, a theoretical Kα x-ray spectrum is obtained, which reproduces very closely a recent experimental result.

Relativistic calculation of two-electron one-photon and hypersatellite transition energies for 12 ⩽ Z ⩽ 30 elements

Energies of two-electron one-photon transitions from initial double K-hole states were computed using the Dirac–Fock model. The transition energies of competing processes, the Kα hypersatellites, were also computed. The results are compared with experiment and to other theoretical calculations.

Production and decay of chlorine ion excited species in an electron cyclotron resonance ion source plasma

The most important processes for the creation of chlorine ion excited states from the ground configurations of Cl10+ to Cl15+ ions in an electron cyclotron resonance ion source, leading to the emission of K x-ray lines, were studied. Theoretical values for inner-shell excitation and ionization cross-sections, including double KL and triple KLL ionization, transition probabilities and energies for the de-excitation processes, were calculated in the framework of the multi-configuration Dirac–Fock method. With reasonable assumptions about the electron energy distribution, a theoretical Kα x-ray spectrum was obtained, which was then compared with recent experimental data.

X-ray-spectroscopy analysis of electron-cyclotron-resonance ion-source plasmas

Analysis of x-ray spectra emitted by highly charged ions in an electron-cyclotron-resonance ion source (ECRIS) may be used as a tool to estimate the charge-state distribution (CSD) in the source plasma. For that purpose, knowledge of the electron energy distribution in the plasma, as well as the most important processes leading to the creation and de-excitation of ionic excited states are needed. In this work we present a method to estimate the ion CSD in an ECRIS through the analysis of the x-ray spectra emitted by the plasma. The method is applied to the analysis of a sulfur ECRIS plasma.

Transition probability values of the 1s22s3p 3P0 level in Be-like ions

Transition probability values from the 1s22s3p 3P0 level for selected beryllium-like ions, from Z = 5 to 92, are calculated using the multi-configuration Dirac–Fock method including QED corrections, and full correlation up to the 4f subshell in both initial and final levels, for 1s22s3s 3S1, 1s22s2p 3P2 level and 1s22p2 3P1 decay modes of this level.

Two-electron one-photon transition relativistic calculations for low-Z elements

Abstract Energies of two-electron one-photon transitions from initial double K-hole states and the transition energies of competing processes, namely K α hyper-satellites, were computed for low- Z elements, using the multi-configuration Dirac–Fock method. Transition rates are also evaluated.

Relativistic Calculations for Trapped Ions

We present recent results in the field of total binding energy calculations, Lande factors, quantum electrodynamics corrections and lifetime that are of interest for ion traps and ion sources. We describe in detail MCDF and RMBPT calculation of ionic binding energies, which are needed for the determination of atomic masses from highly charged ion measurements. We also show new results concerning Lande factor in 3-electron ions. Finally we describe how relativistic calculations can help understand the physics of heavy ion production ion sources.

K X-Ray Energies and Transition Probabilities for He-, Li- and Be-like Praseodymium ions

Theoretical transition energies and probabilities for He-, Li and Be-like Praseodymium ions are calculated in the framework of the multi-configuration Dirac-Fock method (MCDF), including QED corrections. These calculated values are compared to recent experimental data obtained in the Livermore SuperEBIT electron beam ion trap facility [1].