Prebreakdown current inside anode-grid gap of a thyratron

Despite of the fact, that the thyratron was invented more than 50 years ago, it remains as the main switch in high-voltage impulse generators. The process of the discharge formation inside the anode grid gap of a thyratron happens in conditions when the mean free path of electrons is more than the interelectrode anode-grid distance (left-hand side of the Pashen curve). This type of the discharge has been assigned as a high-voltage one, which is the least investigated. In this-connection the objective of the paper is learning processes happening in the anode-grid gap of a thyratron at the prebreakdown period. It is also necessary to work out the method of a measurement of the prebreakdown current