What characteristic should be prioritized when selecting target material for an x-ray tube?

When selecting target material for an x-ray tube, prioritizing a high atomic number is essential because materials with high atomic numbers are more effective at producing x-rays through the process of interaction with accelerated electrons. The high atomic number increases the likelihood of photoelectric absorption, which enhances the efficiency of x-ray production.

Additionally, when high-energy electrons strike the target, the greater the atomic number, the more x-rays are generated due to the effective bremsstrahlung radiation and characteristic radiation produced. This is crucial for achieving the desired image quality and intensity in radiological procedures.

While other characteristics such as a high melting point are important—as they help prevent damage to the target from heat generated during x-ray production—efficiency in x-ray production directly relates to the atomic structure of the material. Good conductivity is also a beneficial quality for a target material, as it helps dissipate heat, but it is not as critical as the atomic number for x-ray generation effectiveness.