Wall conditioning and neutral gas transport at the GDT facility

The effect of wall conditioning on a plasma was studied in the Gas Dynamic Trap (GDT) facility by means of titanium coating of the containment wall. A fter depositing titanium on the inner surface of the vacuum chamber the cha rge-exchange losses of the fast ions turned out to be much less than in for mer, non-conditioned discharges. The temporal and spatial variation of the neutral gas density was measured during typical shots and calculated by mea ns of a Monte Carlo transport code. The comparison of the results numerical simulation with the experimental data are presented.