Discharge lamp having multiple constrictions

Claim 1

A fluorescent lamp comprising: an envelope having a substantially circular configuration in cross-section, said envelope having two axially opposed end portions: first and second electrodes, each of said electrodes located within a respective one of said axially opposed end portions: at least one phosphor layer positioned on the interior surface of said envelope: an ionizable medium enclosed within said envelope including an inert starting gas and a quantity of mercury for producing a plasma discharge when a predetermined voltage is applied across said electrodes, said plasma discharge being characterized by three processes, including: (a) the gain of energy by the electrons in said plasma discharge from the axial electric field established by said voltage and the redistribution of said energy among said electrons to establish an electron energy distribution. (b) the energy losses to said mercury and said starting gas by said electrons and (c) the escape of energy of excited atoms in the form of radiation: and means provided within said envelope for separating at least one of said discharge processes spatially from the remainder of said discharge processes and for causing said separated process to take place in a different portion within said envelope so that the conditions for energy input and energy dissipation may be independently optimized.