Method for sterilizing packaging material, comprising an emitter that is adapted to emit charge carriers, in particular electrons, wherein the charge carriers form at least one cloud, and wherein the emitter and the packaging material are moved relative to each other so that a flow of a gaseous medium is established in between the emitter and the packaging material comprising the steps of: - controlling a movement profile (90', 90") between the emitter and the packaging material; - sterilizing, by the at least one cloud, the flow of the gaseous medium in between the emitter and the packaging material by adjusting the movement profile (90', 90"), wherein the packaging material is basically tube-shaped, and wherein the emitter is adapted for sterilization of at least the interior of the tube-shaped packaging material through an opening of the tube-shaped packaging material - performing a mutual relative movement between the emitter and the tube-shaped packaging material, during which movement a portion of the emitter is temporarily inserted through the opening of the tube-shaped packaging material, such that interior sterilization of the packaging material takes place, wherein inserting the emitter into the basically tube-shaped packaging material creates basically an outflow of the medium out of the basically tube-shaped packaging material through the opening, and wherein pulling the emitter out of the basically tube-shaped packaging material creates basically an inflow of the medium into the basically tube shaped packaging material, - adapting an inflow-speed and an outflow-speed of the medium using the movement profile (90', 90"), wherein the movement profile (90', 90") comprises at least a first position, wherein at the first position the emitter, in particular its electron exit window, and the opening of the basically tube shaped packaging material are basically on the same level, and a second position, wherein at the second position the emitter, in particular its electron exit window, is located inside the basically tube-shaped packaging material, and - adjusting the movement profile (90', 90") so that a time span for moving from the first position to the second position, defined as run-in, is shorter than a time span for moving from the second position to the first position, defined as run-out. - controlling a movement profile (90', 90") between the emitter and the packaging material; - sterilizing, by the at least one cloud, the flow of the gaseous medium in between the emitter and the packaging material by adjusting the movement profile (90', 90"), wherein the packaging material is basically tube-shaped, and wherein the emitter is adapted for sterilization of at least the interior of the tube-shaped packaging material through an opening of the tube-shaped packaging material - performing a mutual relative movement between the emitter and the tube-shaped packaging material, during which movement a portion of the emitter is temporarily inserted through the opening of the tube-shaped packaging material, such that interior sterilization of the packaging material takes place, wherein inserting the emitter into the basically tube-shaped packaging material creates basically an outflow of the medium out of the basically tube-shaped packaging material through the opening, and wherein pulling the emitter out of the basically tube-shaped packaging material creates basically an inflow of the medium into the basically tube shaped packaging material, - adapting an inflow-speed and an outflow-speed of the medium using the movement profile (90', 90"), wherein the movement profile (90', 90") comprises at least a first position, wherein at the first position the emitter, in particular its electron exit window, and the opening of the basically tube shaped packaging material are basically on the same level, and a second position, wherein at the second position the emitter, in particular its electron exit window, is located inside the basically tube-shaped packaging material, and - adjusting the movement profile (90', 90") so that a time span for moving from the first position to the second position, defined as run-in, is shorter than a time span for moving from the second position to the first position, defined as run-out.