NEW RELATIVISTIC APPROACH TO COMPUTING SPECTRAL PARAMETERS OF MULTICHARGED IONS IN PLASMAS

It is presented a new relativistic approach to computing the spectral parameters of multicharged ions in plasmas for different values of the plasmas screening (Debye) parameter (respectively, electron density, temperature). The approach used is based on the generalized relativistic energy approach combined with the optimized relativistic many-body perturbation theory (RMBPT) with the Dirac-Debye shielding model as zeroth approximation, adapted for application to study the spectral parameters of ions in plasmas. An electronic Hamiltonian for N-electron ion in plasmas is added by the Yukawa-type electron-electron and nuclear interaction potential. The special exchange potential as well as the electron density with dependence upon the temperature are used.

Fabrication of a Robust In2O3 Nanolines FET Device as a Biosensor Platform

Field-effect transistors (FETs) are attractive biosensor platforms for rapid and accurate detection of various analytes through surface immobilization of specific bio-receptors. Since it is difficult to maintain the electrical stability of semiconductors of sensing channel under physiological conditions for long periods, passivation by a stable metal oxide dielectric layer, such as Al2O3 or HfO2, is currently used as a common method to prevent damage. However, protecting the sensing channel by passivation has the disadvantage that the distance between the target and the conductive channel increases, and the sensing signal will be degraded by Debye shielding. Even though many efforts use semiconductor materials directly as channels for biosensors, the electrical stability of semiconductors in the physiological environments has rarely been studied. In this work, an In2O3 nanolines FET device with high robustness in artificial physiological solution of phosphate buffered saline (PBS) was fabricated and used as a platform for biosensors without employing passivation on the sensing channel. The FET device demonstrated reproducibility with an average threshold voltage (VTH) of 5.235 V and a standard deviation (SD) of 0.382 V. We tested the robustness of the In2O3 nanolines FET device in PBS solution and found that the device had a long-term electrical stability in PBS with more than 9 days’ exposure. Finally, we demonstrated its applicability as a biosensor platform by testing the biosensing performance towards miR-21 targets after immobilizing the phosphonic acid terminated DNA probes. Since the surface immobilization of multiple bioreceptors is feasible, we demonstrate that the robust In2O3 FET device can be an excellent biosensor platform for biosensors.

Debye screening in generalized quantum electrodynamics

In this work we study the Higgs mechanism and the Debye shielding for the Bopp–Podolsky theory of electrodynamics. We find that not only the massless sector of the Podolsky theory acquires a mass in both these phenomena, but also that its massive sector has its mass changed. Besides exploring the behavior of the screened potentials, we find a peculiar temperature [Formula: see text] associated with the Podolsky length.

Weak Violation of Electroneutrality in the Heliogeospheres: Electroneutrality Disorders

We prove that the occurrence of constant fluxes of positive ions with a large ratio of the charge number (Z) to the mass number of the ion (M) --- Z/M in the solar wind (SW) is due to an insignificant violation of the electroneutrality of the Sun and the entire heliosphere, the absence of Debye shielding of the solar charge due to due to the presence of a constant flux (current) of high-energy electrons from the Sun throughout the heliosphere and the appearance for protons, alpha particles and other positive ions with a ratio Z/M ≥ 0.107, Coulomb mirrors that reflect and accelerate them reflecting and accelerating them from the Sun. For the first time, the effective charge (1.4 kC) and other parameters of a positively charged Sun, which make it possible to estimate the electric field strength (E/N) reduced to particle density (N), were calculated from the ionic composition of SW (according to the minimum Z/M positive ions observed in experiments). This model allowed us to estimate the electric field intensity (E/N) reduced to the density of particles N in the photosphere, chromosphere, corona of the Sun (E/N ≈ 27· 103 Td), heliosphere and to investigate the conditions necessary for reflection of various positively charged particles --- ions from the positively charged Sun

Linear gyrokinetic studies with ORB5 en route to pair plasmas

The model of the global gyrokinetic particle-in-cell code ORB5 has been extended for the study of pair plasmas. This has been done by including the physics of the Debye shielding, by including the electron polarization density and by retaining the effects of the electron finite Larmor radius. This model is verified against previous numerical results for the cyclone base case tokamak scenario in deuterium plasmas, and for local pair plasma simulations. The linear dynamics of temperature-gradient driven instabilities and geodesic acoustic modes is investigated. Mass dependencies for different Debye lengths are studied.

Dust and plasma properties measured using two confined particles

We consider two isolated, interacting dust particles confined in plasma. Measurements of normal mode frequencies are used to determine the dust charge, the Debye shielding length and the anisotropy of the confining potential well. For dust particles confined near the sheath edge, the vertical electric field and an effective electron temperature are also determined. This method is used to characterize the sheath above a short rectangular trench in the powered electrode of a radio-frequency discharge.