Metal halide low-power high-pressure discharge lamp

A low-power, high-pressure, essentially flicker-free discharge lamp suitable for operation at power network frequency, said lamp having

• a discharge vessel (2, 23);
• a fill of mercury, a noble gas, and a metal halide;
• two electrodes (4, 5;
• 25, 26;
• 56;
• 60) in said vessel, each electrode having an electrode shaft (17;
• 38;
• 58;
• 61) and an electrode head (19;
• 39;
• 59;
• 62) at an end portion of the electrode shaft;
• sealing foils (6, 7;
• 27, 28) connected to said electrodes and pressure-sealed into at least one end portion of said vessel, and
• comprising an arrangement of the electrodes for obtaining essentially flicker-free operation when operated at power network frequency and low electrode burn-off, wherein
• each electrode head (19;
• 39;
• 59;
• 62) has an outer shape which is essentially cylindrical or frusto-conical,
• the end or tip of each electrode shaft (17;
• 38;
• 58) extends at most only up to the end of the electrode head (19;
• 39;
• 59;
• 62) at the side which is exposed to the discharge arc;
• the electrode shaft (17;
• 38;
• 58;
• 60) has a diameter d in millimeters defined by the relationship ##EQU4## and wherein the electrode head (19;
• 39;
• 59) and that portion of the electrode shaft (17;
• 38;
• 58) which is within the electrode head has a mass M in milligrams defined by the relationship
• M=i.sub.L .times.(23.+-.8) (2)
• and wherein i.sub.L is the effective value of the lamp current in amperes.