The present approach relates to generating seed electrons at a spark gap in the absence of .sup.85Kr. The present approach utilizes electron emission from a triple-point instead to provide seed electrons to reduce the statistical time lag of a spark gap. In one such implementation, a spark gap a spark gap may be fabricated and/or operated without a radioactive component without otherwise changing its overall form or function of the spark gap.

The present approach relates to generating seed electrons at a spark gap in the absence of .sup.85Kr. The present approach utilizes electron emission from a triple-point instead to provide seed electrons to reduce the statistical time lag of a spark gap. In one such implementation, a spark gap a spark gap may be fabricated and/or operated without a radioactive component without otherwise changing its overall form or function of the spark gap.

A spark plug having an insulating body defining a longitudinal axis and including a base portion and an obstruction portion, a first electrode including a proximal portion, a sheathed portion and a distal portion, the sheathed portion of the first electrode extending through the base portion of the insulating body, and a second electrode including a proximal portion, a sheathed portion and a distal portion, the sheathed portion of the second electrode extending through the base portion and the obstruction portion of the insulating body, wherein the obstruction portion axially extends beyond the distal portion of the first electrode.

A gas turbine igniter includes an igniter rod disposed within a guide tube configured for travel between a hot-end region and a cold-end region and a cap connected to the guide tube, the cap defining an access passageway for the igniter rod. An attachment structure is provided for reducing the moment loading at the cold end of the igniter rod. The attachment structure has threaded outer surface configured to engage in a threaded connection with a threaded inner surface of the cap in an end portion of the cap that is proximate to the cold-end region, whereby the attachment structure is attachable to the end portion of the cap via the threaded connection. An inner surface of the attachment structure forms a guide surface for the igniter rod, at a reduced radial clearance with the igniter rod in comparison to the cap, proximate to the cold-end region.

A gas turbine igniter includes an igniter rod disposed within a guide tube configured for travel between a hot-end region and a cold-end region and a cap connected to the guide tube, the cap defining an access passageway for the igniter rod. An attachment structure is provided for reducing the moment loading at the cold end of the igniter rod. The attachment structure has threaded outer surface configured to engage in a threaded connection with a threaded inner surface of the cap in an end portion of the cap that is proximate to the cold-end region, whereby the attachment structure is attachable to the end portion of the cap via the threaded connection. An inner surface of the attachment structure forms a guide surface for the igniter rod, at a reduced radial clearance with the igniter rod in comparison to the cap, proximate to the cold-end region.

A combustion chamber for a gas turbine is provided. The combustion chamber has a pilot burner device, a fuel injector and an ignitor unit. The pilot burner device has a pilot body with a pilot surface which is facing an inner volume of the combustion chamber. The fuel injector has a fuel outlet for injecting a fuel into the inner volume. The ignitor unit is adapted for igniting the fuel inside the inner volume, wherein the ignitor unit is arranged at the pilot surface such that fuel which passes the ignitor unit is ignitable. The pilot body includes a recess, wherein the fuel outlet is arranged within the recess.

A combustion chamber for a gas turbine is provided. The combustion chamber has a pilot burner device, a fuel injector and an ignitor unit. The pilot burner device has a pilot body with a pilot surface which is facing an inner volume of the combustion chamber. The fuel injector has a fuel outlet for injecting a fuel into the inner volume. The ignitor unit is adapted for igniting the fuel inside the inner volume, wherein the ignitor unit is arranged at the pilot surface such that fuel which passes the ignitor unit is ignitable. The pilot body includes a recess, wherein the fuel outlet is arranged within the recess.

A flexible bellows assembly is disclosed for sealing an engine igniter for use with an engine. The bellows assembly includes a mounting arrangement that is operable to be secured to a combustor diffuser instead of the combustor liner. The bellows has a component that impinges upon a surface of the combustor liner so as to form a sealed chamber between a metal diffuser and a ceramic combustion liner. An igniter passes through the sealed chamber and provides ignition to the combustor.

A flexible bellows assembly is disclosed for sealing an engine igniter for use with an engine. The bellows assembly includes a mounting arrangement that is operable to be secured to a combustor diffuser instead of the combustor liner. The bellows has a component that impinges upon a surface of the combustor liner so as to form a sealed chamber between a metal diffuser and a ceramic combustion liner. An igniter passes through the sealed chamber and provides ignition to the combustor.

A combustion chamber for a turbomachine including an annular casing delimiting an inner volume of the combustion chamber and provided with a chimney extending to the outside of the inner volume and delimiting a passage for a penetrating part, and a bushing mounted floating on the chimney, further includes: a main air collection chamber open to the upstream arranged facing the downstream portion of the chimney; and a through-opening of the annular casing, connecting the inner volume to the main air collection chamber. The air collected by the main air collection chamber is injected into the inner volume via the through-opening and can cool an annular casing zone downstream of the chimney.