Electric-field singlet-triplet anticrossings of the 1snd configurations of 3He atoms

Analytical dependences on a static electric field F 0 are derived for the wavefunctions, matrix elements and probabilities of radiation transitions between multiplet substates interacting in field in pairs, ranging from ordinary doublet states with spin S = 1/2, pairwise interacting sublevels of triplet and quintet states with the magnetic quantum number M = 0, to the most general case of states with arbitrary angular L and spin S momenta and maximal magnitude of the magnetic quantum number |M| = L + S − 1. Equalization of doublet line intensities in the anticrossing field region and vanishing of one of the two doublet lines in the high-field regime are demonstrated. A general relation is determined between the anticrossing field F A , multiplet splitting and tensor polarizability. The data of numerical computations with the Fues' model potential for polarizabilities of triplet states in helium and doublet states in alkali atoms are extrapolated with a three-term polynomial including 5th, 6th and 7th powers of effective principal quantum number and providing accuracy better than 0.5% in a wide range of the principal quantum number n, up to n = 1000.

Section: Numerical Data For Scalar and Tensor Polarizabilities Of Mul...mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Electric-field-induced redistribution of radiation transition probabilities in atomic multiplet lines

Kamenski¹,

Ovsiannikov²

2006

“…Finally we note that the relatively large amplitudes of the 1s5d 1 × 3 anticrossing (dA) at F z = +4.7 kV cm −1 in the 80 keV spectrum is due to the fact that the detection of light emitted by projectile atoms could not be suppressed sufficiently in the energy range, where σ cap (5 1 D) > σ dir (5 1 D). (The amplitude of this anticrossing resonance was significantly smaller when using 60 keV 3 He + instead of 80 keV 4 He + projectiles [11]. )…”

Section: Discussionmentioning

confidence: 90%

Anticrossing spectroscopy of He atoms excited by 30–300 keV He⁺impact

Busch¹,

Drozdowski²,

Ludwig³

et al. 2004

Self Cite

By measuring the anticrossing spectra of the 1s4 and 1s5 He I levels, we investigate single-electron excitation in 30-300 keV He + -He collisions. The post-collisional He I states are highly coherent superpositions of spherical states with large electric dipole moments. These superposition states vary gradually with the impact energy from purely parabolic states at 30 keV to superpositions of 2 states at 300 keV. The results indicate that for the whole energy range single-electron excitation should be considered as a process mainly localized in the saddle region of the two-centre Coulomb potential of the (He + ) 2 molecular core. A theoretical model based on the symmetry of the collision system is discussed.

“…The anticrossing spectra were measured using an apparatus used previously for investigating 4 He + -4 He collisions [2]. The He + ion beam was crossed with a He atomic beam.…”

Section: Measurementsmentioning

confidence: 99%

“…In this case one can take advantage of the fact that there are two stable He isotopes, namely 4 He with nuclear spin I = 0 and 3 He with I = 1/2. The anticrossing spectra of these isotopes differ significantly due to the strong hyperfine coupling present in 3 He, but absent in 4 He [4].…”

Section: Introductionmentioning

confidence: 99%

Anticrossing spectra of³He and⁴He atoms excited by He⁺–He collisions

Busch

Ludwig

Drozdowski

et al. 2006

Self Cite

Singlet–triplet anticrossing spectra of the helium isotope 3He have been measured for the first time. These anticrossing spectra differ strongly from those of the isotope 4He due to the hyperfine interaction. We exploited this difference for distinguishing between the excitation of target atoms and the formation of excited projectile atoms by electron capture in experimental investigations on the symmetric collision system He+–He.