X-ray sources abound around us. They include the following:
Natural X-ray sources: Astrophysical X-ray source, as viewed in X-ray astronomy X-ray background Naturally occurring radionuclides Artificial X-ray sources Radiopharmaceuticals in radiopharmacology Radioactive tracer Brachytherapy X-ray tube, a vacuum tube that produces X-rays when current flows through it X-ray laser X-ray generator, any of various devices using X-ray tubes, lasers, or radioisotopes Synchrotron, which produces X-rays as synchrotron radiation Cyclotron, which produces X-rays as cyclotron radiation