An X-ray tube for accelerating electrons under a high voltage potential, said X-ray tube includes an evacuated elongated housing that is sealed, a through transmission target anode deposited on an inner surface of said elongated housing, said through transmission target anode configured having a cross-sectional center, a cathode structure disposed in said elongated housing, said cathode structure configured to emit the electrons toward said through transmission target anode, two or more filaments disposed linearly in said elongated housing, said two or more filaments linearly positioned end-to-end proximate said cross-sectional center, said evacuated housing configured to vacuum seal therein said two or more filaments, and, thus, such X-ray tube functions to provide a lengthened, elongated, symmetrical radiation field.