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A modern dental X-ray tube. The heated cathode is on the left. Centre is the anode which is made from tungsten and embedded in the copper sleeve. William Coolidge explains medical imaging and X-rays. An X-ray tube is a vacuum tube that converts electrical input power into X-rays. [1]
An X-ray generator generally contains an X-ray tube to produce the X-rays. Possibly, radioisotopes can also be used to generate X-rays. [1]An X-ray tube is a simple vacuum tube that contains a cathode, which directs a stream of electrons into a vacuum, and an anode, which collects the electrons and is made of tungsten to evacuate the heat generated by the collision.
Natural color X-ray photogram of a wine scene. Note the edges of hollow cylinders as compared to the solid candle. William Coolidge explains medical imaging and X-rays.. An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays.
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
In general, an X-ray's beam intensity is not uniform. When it focuses to a target, a conical shape appears (divergent beam). The intensity of the beam from the positive anode side is lower than the intensity from the negative cathode side because the photons created when the electrons strike the target have a longer way to travel through the rotating target on the anode side.
Each element has a unique set of energy levels, and thus the transition from higher to lower energy levels produces X-rays with frequencies that are characteristic to each element. [2] Sometimes, however, instead of releasing the energy in the form of an X-ray, the energy can be transferred to another electron, which is then ejected from the atom.
Megavoltage X-rays are produced by linear accelerators ("linacs") operating at voltages in excess of 1000 kV (1 MV) range, and therefore have an energy in the MeV range. The voltage in this case refers to the voltage used to accelerate electrons in the linear accelerator and indicates the maximum possible energy of the photons which are subsequently produced. [1]
In early and basic X-ray equipment, the applied voltage varies cyclically, with one, two, or more pulses per mains AC power cycle. One standard way to measure pulsating DC is its peak amplitude, hence kVp. Most modern X-ray generators apply a constant potential across the X-ray tube; in such systems, the kVp and the steady-state kV are identical.