Ionization Cross Sections in the Collision between Two Ground State Hydrogen Atoms at Low Energies

Saed J Al Atawneh,Gergő I Pokol,Borbála Szondy,Károly Tőkési,Örs Asztalos

doi:10.3390/atoms8020031

Abstract

The interaction between two ground state hydrogen atoms in a collision was studied using the four-body classical trajectory Monte Carlo method. We present the total cross sections for the dominant channels, namely for the single ionization of the target, the ionization of the projectile, resulting from pure ionization, and also from the electron transfer (capture or loss) processes. We also present cross sections for the complete break of the system, resulting in the final channel for four free particles. The calculations were carried out at low energies, relevant to the interest of fusion research. We present our cross sections in the projectile energy range between 2.0 keV and 100 keV and compare them with previously obtained theoretical and experimental results.

Highlights

Beam emission spectroscopy (BES) is an active plasma diagnostic tool used for density measurements in fusion research [1]
We present a comparative study between atomic collision calculation methods, such as the classical trajectory Monte Carlo method, convergent close coupling (CCC) approach, semi-quantal method, and Born method, in collisions between two ground state hydrogen atoms
To study the collision between two ground state hydrogen atoms, we performed a classical simulation with an ensemble of 5 × 105 primary trajectories for each energy

Summary

Introduction

Beam emission spectroscopy (BES) is an active plasma diagnostic tool used for density measurements in fusion research [1] In this technique, a high energy neutral beam of 2.0–100 keV, composed of typically hydrogen atom, light alkali atoms or their isotopes, is injected into the plasma. The classical trajectory Monte Carlo (CTMC) method is largely employed in collision physics from low to high projectile energies to determine excitation, charge exchange, and ionization cross sections [4]. Atoms 2020, 8, 31 classical trajectory Monte Carlo method was utilized to calculate the doubly-differential cross section of projectile ionization at forward observation angles in the H + H collision system at an impact energy of 70 keV/amu. The theoretical results are compared with the experimental data

Theory

Results and Discussion

Conclusions