A low pressure Ultra Violet (UV) light source produces a high intensity output proportional to the inside diameter and length of a arc discharge column. The light source includes a cathode and anode contained within a high density ceramic body and a sapphire window mounted in line with the arc discharge column. The anode is in line with the arc column at the end opposite the sapphire window, and the cathode is disposed to an area outside the arc discharge column to which the arc moves through an aperture in the side of the arc discharge column structure. As the electrons move through the low pressure gas ionization of the gas occurs releasing photons in the UV region of the spectrum. The sum of the photons generated at each location along the arc discharge column produces the high intensity UV radiation that exits the lamp through a sapphire window.