M.C. Buchet-Poulizac

Beam-Foil Study of the 2s22p53l and 2s2p63l Configurations of FeXVII

The spectrum of Fe XVII has been observed in the 200-450 A wavelength range. A total of 31 lines has been measured and classified as transitions between either the 2s22p53s, 3p, 3d configurations or the 2s2p63s, 3p, 3d configurations. Energy levels of these configurations have been deduced and are compared with other available data. The uncertainty in wavelength determinations leads to a precision on energy levels of the order of 150 cm-1 in most cases.

Beam-foil spectroscopy in the extreme UV of highly ionized silicon Si XI and the isoelectronic ions AI X, S XIII and Ar XV

Spectra of highly-ionized silicon, aluminium, sulfur and argon ions produced by the beam-foil technique have been analysed in the 5-40 nm wavelength range. Numerous transitions belonging to n = 3-4, 4-5 and 3-5 transitions arrays in the beryllium-like spectra Al X, Si XI, S XIII and Ar XV were observed for the first time. The assignment of spectral lines was corroborated by comparison along the isoelectronic sequence.

Measurements of 2s-2p Transition Wavelengths in Helium- and Lithium-Like Xenon

We have measured the wavelengths of the 1s2s3S1-1s2p3P2 transition in heliumlike Xe L III and the 1s22s2S1/2-1s22p2P1/2,3/2 transitions in lithiumlike Xe L II. The measurements were made at GANIL by bean-foil spectroscopy of xenon at 27 MeV/u. The wavelength of (26.66 ± 0.10) A for the 2s3S1-2p3P2 transition in Xe L III compares favourably with the most recent calculation, which includes radiative corrections, relativistic correlations and retardation contributions. The results (103.35 ± 0.08) A and (25.18 ± 0.03) A for the Xe L II 2s2S1/2-2p2P1/2,3/2 transition wavelengths are compared to recent theoretical data resulting from multi-configuration Dirac-Fock and many-body perturbation theories.

Lifetime measurements in O vi, O v, and O iv between 100 and 1700 Å

Emission spectra of O vi, O v, and O iv have been studied in the ultraviolet region from 1700 A to 100 A and the lifetimes of approximately fifty levels of these ions are given. Comparison of these measurements with other experimental as well as theoretical results shows that simultaneous improvement of techniques and calculative methods, including configuration interactions, yields good agreement between experimental and theoretical values.

2s-2p Transitions in two-, three- and four-electron copper ions

Abstract We present wavelength measurement of 2s-2p transitions in two-, three-, and four-electron copper ions in beam-foil excited spectra at 10 MeV/amu. Results in beryllium-like Cu 25+ are compared to Edlens semi-empirical data. Our helium-like Cu 27+ 1s2s 3 S 1 − 1s2p 3 P 2 wavelength is compared with calculations including relativistic and radiative contributions. To fit our experimental value a two-electron Lamb-shift correction has to be added. The lifetime of the upper level 2p 3 P 2 has been measured.

Beam-foil spectroscopy of Mg III–V between 100 and 450 Å

Abstract Magnesium spectra between 100 and 450 A have been studied with the beam foil technique. The observed lines are mainly due to Mg III, IV and V. Radiative lifetimes of eight levels have been measured and are compared with theoretical data. The discrepancy between previous theoretical results for the resonance Mg III lines has lead us to calculate again the transition probabilities of the Mg III ion.

VUV Spectra of Multicharged Recoil-Ions: Neon and Argon

The impact of highly charged and high energy ions in a gas target produces excited recoil-ions. The speed of these ions being quite low, the Doppler shifts and broadening of emitted lines are very small. With a Kr20+ beam at 1.15 MeV/amu, we have observed the spectra of Ne ions in the wavelength range 60-570 A and of Ar ions in the range 150-290 A. In the first one, 130 lines have been identified, classified and compared to previous results. In the second one, 55 lines have been observed, 12 transitions unknown up to now are determined and compared to similar transitions for isoelectronic ions. The 3p4d configuration in Ar V is analysed, taking into account the intermediate coupling.

Beam-foil spectroscopy of nickel and copper at 1.16 MeV/amu

Abstract The beam-foil spectra of nickel and copper obtained at Orsay on the linear injector of the heavy ion accelerator with beams of 1.16 MeV/amu have been analysed in the 110–380 A range. Numerous lines attributed to Ni XVI to XX and Cu XVII to XXI transitions have been identified. The lifetimes of the upper levels of the strongest copper transitions have been measured and are compared with theory and with previous experiments.

The neonlike spectrum of Kr XXVII

Abstract The spectrum of highly-ionized krypton ions produced by the beam foil technique in the 140–270 A wavelength range has been observed. Lines of neonlike krypton Kr XXVII have been identified by isoelectronic sequence extrapolation and compared with ab initio relativistic calculations. The 2p 5 3 l energy levels have been deduced.

Projectile energy loss and final charge state distribution in Xeq+–C60 collisions at low energy

Abstract The projectile final charge state distribution and the energy loss have been studied in frontal collisions between Xeq+ ions (q=15–30) at low velocity (v=0.28 a.u.) and C60 molecule. In our experiment, the frontal collisions are separated from the peripheral collisions by analysing the kinetic energy of the outgoing projectile in coincidence with the recoil ions (stable C60r+ or fragments of C60) and the number of ejected electrons. The energy losses are found equal to 760±150, 900±150 and 1300±300 eV for Xe15+, Xe25+, Xe30+ incident ions respectively.