logging in or signing up production of x-rays Relota Download Post to : URL : Related Presentations : Let's Connect Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Copy embed code: Embed: Flash iPad Dynamic Copy Does not support media & animations Automatically changes to Flash or non-Flash embed WordPress Embed Customize Embed URL: Copy Thumbnail: Copy The presentation is successfully added In Your Favorites. Views: 68 Category: Others/ Misc License: All Rights Reserved Like it (0) Dislike it (0) Added: February 23, 2012 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript Production of X Rays: Production of X Rays Dr. Varun Babu MD Resident Dept. of Radiology AIMS, Cochin 1 June 2011X ray tube: X ray tubeX ray tube: X ray tubeDiagnostic X ray tubes: Diagnostic X ray tubes Made of Pyrex glass that encloses a vacuum containing two electrodes. Cathode electrons Anode Why Vacuum?Cathode: CathodeX ray tube Current: X ray tube Current Number of electrons flowing per second from filament to target mAFilament: Filament Tungsten wire Thermionic emission Thermal energy Electron emission Tungsten thermions (2000 0 C)Space charge and Space charge effect: Space charge and Space charge effect Space Charge Electrons emitted from the tungsten filament form a small cloud in the immediate vicinity of the filament. Prevents other electrons from being emitted from the filament until they have acquired sufficient thermal energy to overcome the force caused by the space charge Space charge effect Tendency of the space charge to limit the emission of more electrons from the filamentCathode Focusing Cup: Cathode Focusing Cup Prevents the forces of mutual repulsion of electrons resulting in spreading out and bombardment of anode over a large area NickelLine Focus Principle: Line Focus Principle Of the electrons striking the anode, <1% is converted to X rays, remaining is heatAnode - Types: Anode - TypesStationary Anode: Stationary Anode Small plate of tungsten embedded in a large mass of CopperRotating Anode: Rotating Anode A large disc of tungsten/alloys of tungsten, which theoretically rotates at speed of about 3600 rpmRotating Anode: Rotating AnodeHow to rotate the Anode: How to rotate the AnodeGrid controlled X ray tubes: Grid controlled X ray tubes Contains its own ‘switch’ – allows X rays to be turned on and offSaturation voltage: Saturation voltage Above a certain saturation voltage, the space charge effect, theoretically has no influence on current flowing in the X ray tubeHeel effect: Heel effect Intensity of the X ray beam that leaves the tube is not uniform throughout all portions of the beam It depends on the angle at which the X rays are emitted from the focal spotTube Shielding and High voltage cables: Tube Shielding and High voltage cables Tube housing absorb primary and secondary x rays Provides shielding from high voltages required to produce X raysElectron orbits and energy levels: Electron orbits and energy levels Binding force – potential energy Kinetic energy Electron movement to a lower energy shell – emission of energy – photon Forbidden transitionInteraction of Electron beam with X ray tube target: Interaction of Electron beam with X ray tube targetGeneral Radiation: General RadiationCharacteristic Radiation: Characteristic RadiationIntensity of X ray beams: Intensity of X ray beams Target material Voltage applied Tube current FiltrationTo summarize..: To summarize.. X rays are produced by energy conversion when a fast-moving stream of electrons is suddenly decelerated in the target of an X-ray tube An X ray tube is a specially designed vacuum diode tube. Heat production in the tube is minimized by using the line focus principle and a rotating anodeTo summarize..: To summarize.. X rays are generated by two different processes Production of a continuous stream of X rays ( Bremsstrahlung ) Characteristic X rays Quanity of X rays generated is proportional to Atomic number of the target material (Z) Square of the kilovoltage ( kVp ) 2 Current of the X-ray tube Quality of the X rays generated depends almost entirely on the X ray tube potentialPowerPoint Presentation: Thank you for your patient listening You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.