Radiation Sources: Flat Panel X-ray Source

Soon after the discovery of x-rays, and the realization that they can alter material and biological properties, people tried sterilizing food and other agricultural products with them. Traditional x-ray tubes were never very successful at this, since they use a single cathode that make a single x-ray spot on the anode (or track on a rotating anode). Most of the power put into an x-ray tube is converted to heat, and managing the heat on the anode spot proved to be the limiting factor.

The Flat Panel X-ray Source (FPXS) solves this problem in several ways. By using a cathode array to generate the electron beams that accelerate at high voltage across vacuum to hit the anode and make the x-rays, power is spread over the anode by several orders of magnitude compared with a point-source tube. FPXS has one side of the anode facing the external environment so it can be directly cooled. FPXS doesn’t have the “heel effect” of an x-ray tube, which increases source efficiency, and the source area can be matched to the irradiation target area, which increases system efficiency. These factiors make FPXS more power efficient than x-ray tubes, for operation at lower power consumption and higher x-ray flux output over longer periods.