A short arc lamp incorporates a cylindrical reflector body having a reflector cavity opening to a first end and an anode aperture through a base surface at a second end. The body has a step at the second end. A front sleeve with a step for positional engagement of a land is received over the first end of the reflector body. A cathode support is received within the second end of the front sleeve and includes a ring to engage a second oppositely oriented positioning step. A window mount received within the second end of the front sleeve abuts a front surface of the ring. A highly conductive base concentrically supporting an anode received through the anode aperture has a flange in flush abutment with the base surface for braze attachment.