This is a page devoted to the equipment used for radiographic work, both medical and industrial.

Photon sources[1]

X-ray sources

A high energy X-ray machine can be used for industrial radiography while for medical radiography a lower voltage can be used with a sealed X-ray tube, it is often important to use a high accelerating voltage to provide the electrons with a very high energy, this is because in a braking radiation source the maximum photon energy is determined by the energy of the charged particles. A recent development is the betatron, which is a device similar to a cyclotron that acts as a very intense photon source.[2][3] Radiography is the use of ionising electromagnetic radiation to view objects. ... Radiography is the use of ionising electromagnetic radiation to view objects. ... An X-Ray tube is a vacuum tube designed to produce man made X-Ray photons on demand. ... Bremsstrahlung, German for braking radiation, is electromagnetic radiation produced by the acceleration of a charged particle, such as an electron, when deflected by another charged particle, such as an atomic nucleus. ... A betatron is a particle accelerator developed by Donald Kerst at the University of Illinois in 1940 to accelerate electrons. ... A pair of Dee electrodes with loops of coolant pipes on their surface at the Lawrence Hall of Science. ... The word light is defined here as electromagnetic radiation of any wavelength; thus, X-rays, gamma rays, ultraviolet light, microwaves, radio waves, and visible light are all forms of light. ...

Radioisotope sources

These have the advantage that they do not need a supply of electrical power to function, but they do have the disadvantage that they can not be turned off. Also it is difficult using radioactivity to create a small and compact source which offers the photon flux which is possible with a normal sealed X-ray tube. One of the leading makers of radiographic equipment is the Source Production & Equipment Co., Inc. [4] Radioactivity may mean: Look up radioactivity in Wiktionary, the free dictionary. ... An X-Ray tube is a vacuum tube designed to produce man made X-Ray photons on demand. ...

It might be possible to use Cs-137 as a photon source for radiography but this isotope has the disadvantage that it is always diluted with inactive cesium isotopes. This means that it is difficult to get a physically small source, a large radioactive volume of the source will make it impossible to get the finest detail from a radiographic examination. Caesium-137 is a radioactive isotope which is formed mianly by nuclear fission (half life is about 27 years). ...

Both cobalt-60 and cesium-137 have only a few gamma energies which make them close to monochromatic. The photon energy of cobalt-60 is higher than that if cesium-137 which allows cobalt sources to be used to examine thicker sections of metals than those which could be examined with Cs-137. Iridium-192 has a lower photon energy than cobalt-60 and its gamma spectrum is complex (many lines of very different energies), but this can be an advantage as this can give better contrast for the final photographs.

It has been known for many years that an inactive iridium or cobalt metal object can be machined to size. In the case of cobalt it is common to alloy it with nickel to improve the mechanical properties. In the case of iridium a thin wire or rod could be used. These precursor materials can then be placed within stainless steel containers which are leak tested before being converted into radioactive sources. These objects can be processed by neutron activation to form gamma emitting radioisotopes. The stainless steel has only a small ability to be activated and the small activity due to ⁵⁵Fe and ⁶³Ni are unlikely to pose a problem in the final application because these isotopes are beta emitters which have very weak gamma emission. The ⁵⁹Fe which might form has a short half life, so by allowing a cobalt source to stand for a year much of this isotope will decay away. General Name, Symbol, Number iridium, Ir, 77 Chemical series transition metals Group, Period, Block 9, 6, d Appearance silvery white Atomic mass 192. ... This article or section does not cite its references or sources. ... An alloy is a combination, either in solution or compound, of two or more elements, at least one of which is a metal, and where the resulting material has metallic properties. ... The 630 foot high, stainless-clad (type 304) Gateway Arch defines St. ... The radiation warning symbol (trefoil). ... Neutron activation is the process by which neutron radiation induces radioactivity in materials. ... Alpha radiation consists of helium nuclei and is readily stopped by a sheet of paper. ...

The source is often a very small object which needs to be transported to the site where the work is to be conducted in a shielded container. It is normal to place the film in industrial radiography, clear the area where the work is to be done, add shielding (collomators) to reduce the size of the controlled area before exposing the radioactive source. A series of different designs have been developed for radiographic "cameras". Rather than the "camera" being a device which accepts photons to record a picture, the "camera" in industrial radiography is the radioactive photon source. In telecommunication, the term controlled area is an area in which uncontrolled movement will not result in compromise of classified information, that is designed to provide administrative control and safety, or that serves as a buffer for controlling access to limited-access areas. ...

Torch design of radiographic cameras

One design is best thought of as being like a torch. The radioactive source is placed inside a shielded box, a hinge allowed part of the shielding to be peeled back exposing the source so allowing the photons to leave the radiography camera.

A torch type camera which uses a hinge. The radioactive source is in red, the shielding by blue/green and the gamma rays are represented by yellow

Another design for a torch is one where the source is placed in a metal wheel, this can turn inside the camera to move between the exposed and storage sites.

A torch type camera which uses a wheel design. The radioactive source is in red and the gamma rays are represented by yellow

Cable based design of radiographic cameras

One group of designs use a radioactive source which comes out on a cable from a shielded container.[5] One such unit was involved in an accident [6] which occurred in Bolivia. This type of radiography could be compared to the remote afterloading method in Brachytherapy. In one design of equipment the source is stored in a block of lead or DU metal which has a S shaped tube like hole which passes through the block. In the safe position the source is in the centre of the block and is attached to a metal wire which extends in both directions, to use the source a guide tube is attached to one side of the block while a drive cable is attached to the other end of the short cable. Using a hand operated winch the source is then pushed out of the shield and along the guide tube to were it is needed. Brachytherapy for prostate cancer is administered using seeds, small radioactive rods implanted directly into the tumour. ... For PB or pb as an abbreviation, see PB. General Name, Symbol, Number lead, Pb, 82 Chemical series poor metals Group, Period, Block 14, 6, p Appearance bluish white Atomic mass 207. ... DU, Du, or du may refer to: Data unit Delhi University Delta Upsilon Democratic Underground Depleted uranium Desktop underwriter Dial-up access Disney University Dobson unit Doctor of the University Doshisha University Drexel University Ducks Unlimited Duisburg (city code plate prefix) Duke University Duquesne University Hemus Air (IATA airline designator...

A diagram of the S shaped hole which passes through a metal block, the source is stored at point A and it is driven out on a cable through a hole to point B. It will oftein go a long way along a guide tube to where it is needed.

Microsecond X-ray pulses

It is possible using a particle accelerator to generate a short pulse of high energy electrons, these electrons are used to create X-rays by braking radiation.[7]. The X-rays are detected using a semiconductor detector which is an array of silicon diodes. Such equipment has been used for the X-ray version of high speed flash photography. For example using diesel (motor fuel) which has been doped with cerium the operation of fuel injectors has been investigated.[8][9]. Bremsstrahlung, German for braking radiation, is electromagnetic radiation produced by the acceleration of a charged particle, such as an electron, when deflected by another charged particle, such as an atomic nucleus. ... A semiconductor is a solid whose electrical conductivity can be controlled over a wide range, either permanently or dynamically. ... General Name, Symbol, Number silicon, Si, 14 Chemical series metalloids Group, Period, Block 14, 3, p Appearance as coarse powder, dark gray with bluish tinge Atomic mass 28. ... Types of diodes closeup, showing germanium crystal In electronics, a diode is a component that restricts the direction of movement of charge carriers. ... Running water frozen by flash. ... General Name, Symbol, Number cerium, Ce, 58 Chemical series lanthanides Group, Period, Block n/a, 6, f Appearance silvery white Atomic mass 140. ...

Some examples of radiography done using a 5 MeV electron LINAC driving a bremmstrahlung source (1 mm Tungsten on a 9 mm copper sheet) can be seen here.[10] A Linear particle accelerator is an electrical device for the acceleration of subatomic particles. ... General Name, Symbol, Number tungsten, W, 74 Chemical series transition metals Group, Period, Block 6, 6, d Appearance grayish white, lustrous Atomic mass 183. ... General Name, Symbol, Number copper, Cu, 29 Chemical series transition metals Group, Period, Block 11, 4, d Appearance metallic pinkish red Atomic mass 63. ...

As an alternative high energy pulsed proton beams can be used for the high speed examination of objects.[11] // For alternative meanings see proton (disambiguation). ...

Neutron sources

In some cases, industrial radiography is done with neutrons. This type of radiography is called Neutron Radiography (NR, Nray, N-Ray) or Neutron Imaging. Neutron Radiography can see very different things than X-rays, because neutrons can pass with ease through lead and steel but are stopped by plastics, water and oils. Neutron sources include radioactive (²⁴¹Am/Be and Cf) sources, electrically driven D-T reactions in vacuum tubes and conventional critical nuclear reactors. It might be possible to use a neutron amplifier to increase the neutron flux.[12] This article or section does not cite its references or sources. ... This article or section does not cite its references or sources. ...