Effects of time on the evolution of a wave packet in the tunneling dynamics

We investigate the time-dependent electron wave packet in a one-dimensional geometry with the potential bent by a homogeneous external field. Based on the behaviors of the wave packet over time, we observe a crossover time. After this crossover time, the temporal evolution of the wave packet comes into a new regime, where the wave packet evolves in a self-similar structure. To establish the time scale of this crossover quantitatively, we utilize the Loschmidt Echo function, through which the time at which the crossover occurs can be extracted. We also find the time of the maximum ionization velocity can be comparable with the semi-classical tunneling delay time.

Hard X-ray impact on the ionosphere D-layer: new results from VLF measurements

<p>The ionospheric electron density reacts to a change of ionization condition by a time delay Δt. Appleton (1953) demonstrated that this time delay is inversely proportional to the product of the electron density Ne and recombination rate coefficient α. Thus, the evaluation of the time difference between the peak time of VLF emission, which is supposed to represent the instant of maximum ionization, and the ionization source's peak time provides an easy way to estimate α Ne. First used to evaluate the increase of electron density at noon from H α peak emission, this technic was also employed to estimate the recombination rate during solar flares. The GOES Soft X-ray emissions (i.e. in the range 1.5-12keV) are then considered to determine the ionising source peak time.</p><p>Based on VLF measurements obtained from the SUPERSID antenna installed at the Meudon site of the Paris Observatory (France), we computed each flare's time delay from January 2017. We benefit from the events of September 2017, the strongest from the last 10 years. We thus demonstrate the prominent role of Hard X-Rays in ionizing the D-layer of the ionosphere.  </p>

Maximum Ionization in Restricted and Unrestricted Hartree-Fock Theory

In this paper, we investigate the maximum number of electrons that can be bound to a system of nuclei modelled by Hartree-Fock theory. We consider both the Restricted and Unrestricted Hartree-Fock models. We are taking a non-existence approach (necessary but not sufficient), in other words we are finding an upper bound on the maximum number of electrons. In giving a detailed account of the proof of Lieb’s bound [Theorem 1, Phys. Rev. A 29 (1984), 3018] for the Hartree-Fock models we establish several new auxiliary results, furthermore we propose a condition that, if satisfied, will give an improved upper bound on the maximum number of electrons within the Restricted Hartree-Fock model. For two-electron atoms we show that the latter condition holds.

O VI Profiles of Solar Quiet and Active Areas Recorded by OSO-8 L.P.S.P. Experiment

O VI resonance line (2s2S - 2p2PO , 103.19 nm) is formed in the chromosphere-corona transition zone with a temperature of maximum ionization of 350 000°C (Jordan, 1969). The OSO-8/LPSP experiment has observed this line with a 0.006 nm resolution, few arcseconds angular resolution and a time resolution up to few seconds. We present the shape of the line in different areas on the sun (quiet and active). As transition lines are used to determine propagation of wave from chromosphere to corona, we compare width of the O VI line with other measurements obtained with lines of lower ionization temperature. From successive profiles we consider the possibility of direct measurements of wave propagating.