Abstract: An x-ray apparatus and method for irradiating products, e.g. food, includes a hot electron plasma annulus confined by a simple magnetic mirror. The device includes a chamber for confining a gas, heated by microwave energy. The chamber has a central cylindrical opening into which the product is placed or conveyed through to receive x-rays radiating from the chamber. A number of chambers may be arranged coaxially in series to increase product throughput or arranged in an array to irradiate larger products.