Whereconvenient, the combination may comprise more particularly means 10 for directing radiant energy 11 from a laser 12 onto a target 13 to produce such X-rays 14 at the target 13, and means 15 for so positioning the target 13 adjacent to the desiredlocation at 16 as to emit the X-rays 14 toward the desired location 16.Where preferred, the combination may comprise means, such as 10 (or any other