Gas-insulated high or medium voltage circuit breaker

A gas-insulated high or medium voltage circuit breaker comprising:

• a first arcing contact and a second arcing contact, wherein at least one of the two arcing contacts is axially movable along a switching axis, wherein during a breaking operation, an arc between the first arcing contact and the second arcing contact is formed in an arcing region;
• a nozzle including a channel directed to the arcing region, for blowing an arc-extinguishing gas to the arcing region during the breaking operation;
• a diffuser portion adjacent to the nozzle, for transporting the arc-extinguishing gas from the arcing region to a region downstream of the diffuser portion;
• a buffer volume directly downstream of the diffuser portion;
• an enclosure confined within a housing of the circuit breaker, wherein the enclosure substantially surrounds the buffer volume circumferentially;
• and
• a buffer dividing member connected to the diffuser portion as to divide the buffer volume into a first and a second buffer sub-volume, wherein the buffer dividing member has one or more apertures allowing a flow of gas between the first and the second buffer sub-volume through the buffer dividing member,
• wherein the buffer dividing member is substantially disc-shaped and substantially extending radially.