Absolute cross section for near-threshold two-electron photoionization ofHe−

Threshold behavior in single-photon double ionization of atomic oxygen

“…Early studies of electron impact on the He atom by Cvejanovic and Reed [13]showed that the ionization cross section does indeed follow the Wannier behavior. With the use of high power lasers, several singly charged negative ions such as H, He, and K have been tested by Donahue et al [14], Bae, Coggiola, and Peterson [15], and Bae and Peterson [16].The results of H and K are also consistent with the Wannier theory although they can be fitted equally well with the Temkin's theory. Later, Kossman, Schmidt, and Andersen [17] investigated the threshold behavior of the helium atom using vacuum uv radiation from a synchrotron storage ring.…”

Oscillations in the Double-Photoionization Cross Section of Li near Threshold

“…First attempts to verify Temkin's model showed possible oscillations in the double-photodetachment cross section of H ÿ [19], He ÿ [20], and K ÿ [21]. These experiments proved to be inconclusive, but a later analysis [22] showed that the results of both experiments reveal the presence of structure and are not in agreement with Wannier's power law.…”

Heterojunction Bipolar Transistor with an Additional Minority Carrier Reflection Barrier in the Emitter

“…In figure 6 we compare our results in the region 0.0-0.5 eV with the experimental values of Bae et al [20] and with the semiclassical calculations of Crothers and Lennon [22]. The experimental values were given large uncertainties.…”

“…Crothers and Lennon stated ( [22], p L411) that this model produced a favourable comparison with the experimental values [20], which cover the energy range from threshold to 0.41 eV above, but which were assigned large uncertainties. Actually, the interesting feature of figure 3 of [20] is that there appears to exist a plateau up to about 0.2 eV with σ ++ (E) ≈ 0.5 × 10 −20 cm 2 and then a sharp rise to σ ++ (E) ≈ 2.0 × 10 −20 cm 2 , from 0.2 to 0.4 eV. Neither the semiclassical [22] nor the present quantum mechanical calculations reproduce this feature.…”

“…Aspects of the features of the σ ++ (E) for process (1) have been published as results of measurements [20] and of two theoretical investigations [21,22]. Of the latter, the first was reported by Nicolaides [21] and covered the photon energy range 6.53-24.80 eV.…”