Journal of Atomic, Molecular, Condensed Matter and Nano Physics

Ionization of the \(1S\) and \(nS\) States of the Atomic Hydrogen by Positron and Electron Impacts

A. K. Bhatia — 2025-10-26

The ionizations of the \(1S\) and \(nS\) states of the atomic hydrogen have been carried out using the hybrid theory, which is variationally correct and has been obtained by modifying the method of polarized orbitals. Earlier, we calculated cross sections of exciting the higher states from the ground state, and cross sections of photoabsorption. Now, we apply the same approach to the ionization of states. The distortion of the orbit is considered due to the incident positron or electron. The distortion takes place whether the incident particle is outside or inside the orbit. Temkin considered distortion of the target electron only when the incident particle is outside the orbit of the target. However, there is no simple way to consider distortion of \(nS\) states of atomic hydrogen. The cross sections are calculated by considering the distortion in the initial state as well as in the final state only in the \(1S\) state and are compared with the previous calculations and the experimental results. The present cross sections have a maximum at an energy which is the same as the incident energy in the experimental results.

Variational Principles and Their Applications

A. K. Bhatia — 2025-10-26

There are many variational calculations of energies of various systems which have applications in Rydberg states and polarizabilities of these systems. There are variational calculations of scattering functions which have applications in calculations of excitation, photoabsorption, and radiative attachment cross sections. A few of these applications are mentioned.

New Q-\(\beta\)-Decay theory applied to the calculations of the rest mass energy \(m_0c^2\) of the electron and of the Q-value for \(\beta^+\)-decay transitions in mirrors nuclei \(A = 2Z – 1\)

Ibrahima Sakho — 2025-10-26

4F and 5F Excitations of Atomic Hydrogen by Electron Impact

Anand K. Bhatia — 2025-10-26

The excitation cross sections of the 4F and 5F states of atomic hydrogen by electron impact have been calculated at incident energies 1.00 to 42.25 Ry, using the hybrid theory, which is variationally correct. The present calculation is a single-channel or a distorted wave calculation. Partial waves ranged from L=3 to 14 to obtain converged results. Excitations of higher states are needed for diagnostics of the solar and astrophysical plasmas. They are also needed to model plasma in fusion research, because they indicate the possibility that a state will be excited to a higher state when colliding with another state. Transition rates to the lower states can be measured by observing decays of the excited states.

Excitation of (1s2s) 1S, the Singlet State of Helium Atoms by Positron Impact

Anand K. Bhatia — 2025-10-26

The excitation of the (1s2s) 1S state of a helium atom has been calculated using scattering functions obtained by the method of polarized orbitals. In this method, the distortion of each orbital is considered due to the presence of the incident particle. The distortion takes place only when the incident particle is outside the target orbital. This method has been widely used in the scattering of electrons and positrons from various targets. Plane-wave normalization of the continuum function is considered, while it has been neglected in calculations carried out by Mandal et al. and Willis and McDowell. Consequently, the present results are higher than those obtained by them.

Concentration Method of Nanobubble Aqueous Solutions at External Electric Field

Hyokmin Ri — 2025-10-26

Nanobubbles have been widely applied in wastewater treatment, cleaning, medical and agricultural fields. The concentration of nanobubbles in nanobubble solutions generated by different nanobubble generation methods is very small, as low as <109 ml-1 (0.001 vol%). So, it is difficult to measure the size and concentration of the generated nanobubble solutions using a laser particle size analyzer (LPSA). To solve this problem, we proposed a method to concentrate nanobubble solutions using an external electric field. To account for the feasibility of the proposed method, the concentration process is simulated using “COMSOL Multiphysics” program. Based on the simulation results, the concentration experiments of nanobubble solutions prepared by ultrasonic cavitation is carried out. The measurements of the nanobubble solution before and after concentration using the LPSA device confirmed that the nanobubble solution can be concentrated by applying an external electric field.