Understanding the mechanism of electron molecule collision can help predict the operation of ITER reactor fusion chamber. In a new paper, physicists calculated the efficiency of a reaction involving an incoming electron kicking an electron out of a metal beryllium (be) or its hydrogen compound molecule.

Understanding the mechanism of electron molecule collision can help predict the operation of ITER reactor fusion chamber.

An international team of physicists has calculated the efficiency of a reaction in an article to be published in the European Journal of Physics D, which involves an incoming electron kicking an electron out of a metal beryllium (be) or its hydrogen compound molecule.

The efficiency depends in part on the speed of electron entry and is encapsulated in a quantity called electron impact ionization cross section (EICS). Electron molecule interactions are important because they appear in a wide range of applications, from the simplest fluorescent lamps to the most complex applications, such as ionized substances found in plasmas, such as the latest generation of screens, outer space of the universe, and fusion reactors.

In the prototype of the future fusion reactor currently being built in southern France, beryllium enters the plasma because it is one of the constituent materials of the fusion chamber wall. When contacting with hot hydrogen plasma, the wall is eroded to form gaseous beryllium and beryllium hydride, beh and beh2, which exist in various forms of charge and state.

Considering the invasion of beryllium in hydrogen plasma, nuclear fusion requires the knowledge of EICS to predict and simulate its operation. The problem is that EICS is difficult to calculate accurately. On the contrary, the author relies on two approximate methods, namely deutsch-m ä rk (DM) and binary encounter bethe (beb). Although these methods are not new, they have never been applied to beryllium and its derivatives before.

In order to use these models, the authors first collected the necessary input data obtained from quantum chemical calculations, such as orbital energy, kinetic energy and orbital population. In order to facilitate the ITER team to use their EICS, the author finally converted the numerical cross section into the equation used in the simulation code.