An HID arc tube, a manufacture method thereof, an illumination device and an illumination
system are provided. The manufacture method for HID arc tube includes: forming a
bulb shell which includes a
discharge cavity (5) and outer shells (1) extending from two ends of the
discharge cavity (5) respectively, wherein forming a conical hollow location part (11) neighboring the
discharge cavity (5) in the outer shell (1). The outer
diameter and the inner
diameter of the hollow location part (11) decrease synchronously and gradually along the direction to the discharge cavity (5), and the thickness of the tube wall does not change. An
electrode location part (9) with a shape of trapezoid and cone is formed, and the
electrode location part has a
conical surface which can tightly combine with the hollow location part (11), and the
electrode location part can be used to fix the electrode (8) and make the electrode (8) enter into the discharge cavity (5) with a predetermined length (L) when the
electrode location part (9) is tightly combined with the hollow location part (11). The
electrode location part, on which the electrode (8) is fixed, enters into the hollow location part (11), and tight combination between the
electrode location part (9) and the hollow location part (11) is realized. The method can make the arc tube have accurate electrode space, improve the vacuum and cold
junction temperature, and improve the luminous efficiency, lifetime, and consistency of the product.