Ceramic discharge lamp arc tube seal

An arc discharge metal halide lamp for use in selected lighting fixtures, said lamp comprising:

• a discharge chamber having visible light permeable walls of a selected shape bounding a discharge region through which walls a pair of electrode assemblies are supported with interior ends thereof positioned in said discharge region spaced apart from one another, and with said electrode assemblies each also extending through a corresponding capillary tube affixed to said walls to have exterior ends thereof positioned outside said arc discharge chamber;
• and
• at least one of said electrode assemblies comprising an electrode discharge structure located at said interior end of that said electrode assembly with said electrode discharge structure having a discharge region shaft extending into said capillary tube corresponding thereto, and further comprising a helical coil positioned in part about said discharge region shaft in said corresponding capillary tube and extending outwardly in said corresponding capillary tube to be in direct contact with an interconnection shaft extending outside of said corresponding capillary tube to provide said exterior end of that said electrode assembly.