Metal halide lamp and lighting system

摘要

A metal halide lamp (10) comprises: a discharge chamber (20) having a light-transmissive chamber wall structure (25) which defines a discharge region (201), a first electrode, and a second electrode, the first and second electrodes being positioned opposite to each other; and an ionizable material contained in the discharge region (201), the ionizable material including mercury, rare gas, and at least two types of halides which includes praseodymium halide and sodium halide, wherein a diameter D of the chamber wall structure (25) and an electrode separation distance L between the first and second electrodes cross each other substantially at right angles and satisfy the relationship of L/D>4.