Effect of Wall Conditioning on Neutral Gas Transport in the Gas-Dynamic Confinement System

A system of electric arc evaporators for fast Ti-coating has been installed inside the gas dynamic trap (GDT) of the Budker Institute Novosibirsk. In this way the vacuum conditions could be substantially improved and consequently the plasma parameters especially those of the fast ions remarkably increased. The fast ion lifetime raised up by more than one order of magnitude. Under the new conditions special experiments were carried out to study the neutral gas dynamics inside the GDT and to compare with numerical results which were obtained by means of the Monte Carlo code TUBE.