Abstract: A gas-laser arrangement in which the laser medium is optically pumped. An arc or spark discharge is formed to a helix, particularly by an axial magnetic field. The volume surrounded by the helical arc or spark discharge is optically excited, unimpeded by a physical wall, by radiation from the discharge, especially in the vacuum-uv spectral region, or by resonance lines. Due to the temperature difference between the helical discharge and the gas column along the helix axis, an inversion may be produced in the vicinity of the axis by appropriate choice of gas and the gas composition.

Abstract: An improved arc quenching arrangement for a gas-flow circuit breaker apparatus of the type including a housing; a body of electrical insulation material disposed within the housing and forming an arc quenching gap therewithin; at least one gas flow canal disposed within the body of insulation material for directing a quenching gas from a space within the housing to the vicinity of the quenching gap; fixed and movable electrical contacts disposed within the housing adjacent the housing quenching gap; and a check valve disposed in the flow canal for permitting the flow of the arc quenching gas only from the space within the housing to the quenching gap formed by the body of insulation material. The improvement of the invention comprises the extension of the gas flow canal to the arc quenching gap formed by the body of insulation material and the disposition of the check valve at the end of the flow canal at the arc quenching gap. An improved arc quenching effect for large current flow is thereby achieved.