How many parts of the x-ray machine and x-ray tube PDF download

How many part of the x-ray machine?

1. X-ray tube

1. Operating console

1. High voltage transformer

1. Tube head & protective housing

1. Bucky

1. Colimeter

1. Gride

1. Patient table

1. Radiographic film

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X-RAY TUBE :-
             The part of the x-ray tube have two major component :-

1. Cathode 

1. Anode 

1. Glass envelop

1. The cathode  :-

• Cathode has a negative electrical charge
• Contain two major components

1. Filament
2. Focusing cup

1. Filament :-

• This is a negative because it is a source of electron
  
•            
• Note that the diaphragm show a magnified view of face and it's show dual filament.
• Only one filament at time will work.
• The small filament designed to be used with relatively small part while the larger filament is used when the larger body part being X-RAYs.
• The structure which support the filament is. Known as the "focusing cup".
• It is designed and shaped so that when the X-RAY machine powered up, electron will literally "boil"of the filament.
• It glows White hot and the elecrtons however the filament Ina space" charge" until the moment of the exposure and they accelerate very rapidly towards the anode which is not very far away .

This process is known as a "thermionic emmision".

• The thermionic emission occur when the technologist being make an exposure by pressing the "ready" button on the machine.
• This action initiates the "boost phase" or that part of the exposure process, where the X-RAY tube is being prepared for he exposure to take the place.
• While can not the see the actual Shep of the focusing cup, it is designed such that it help"concentrate "the electron stream in a predetermined area of the anode target area known as the" focal spot".
• The filament has its own circuit powered by a reletevly low voltage and 4-6amps.
• 
  
• 2. Focusing cup :-   How the focusing cup works 

• Shape of focusing cup works 
• Projectile electron stream  
  

       

• We have to examples of how  electron can function given two difference conditions.
• In the model of top you will see that because of electron repulse each other , as soon as they leave the structure the electron tend spread out.
• The is would not conducive to good x-ray production.
• The spread out the occur because the focusing cup is not negatively charged.
• In the second model , you will notice that cathode structure is negatively charged.
• This changed then forces the electron together as they exit the cathode structure thereby ensuring that the electron stream does not strike the focal spot in relatively small parts.
• Focusing cup use:-

           - support the filaments
           - controls trajectory of projectile                       electrons.
           - made of molybdenum nickel alloy.

• In summary, cathode structure contains the filament and the focusing cup.
• The purpose is filament cut is to guide the electron stream to the target area on the anode.
• Because of tremendous amount of the heat the is generated cathode.
• The structure is made of molybdenum nickel alloy which has excellent thermal qualifies.

2. THE ANODE. :-

• Anode has a positive electron charge
• Attracts electrons
• Has a specific area where the projectile electrons impact focal spot, large vs small
• The second major part of x-ray is the anode 
• The anode has a positive electrical charge and attracts electrons when the exposure machine is pressed.
• The anode is actually a disc made of tungsten because of its thermal qualities also.
• The disc is designed to rotate during operation.
• Recall how the cathode is positioned in relation to the anode and you can that the electron stream will strike at the electrons stream will strike the lower part of the disc along an area called the focal track .
• It is called a track because the anode rotates very fast an the idea is for the electron not concentrate on any given spot for any length of time.
• Rotation "spreads" the build up of heat along the entire disc rather than just given spot.
• The specific spot along the track where the electrons stream strikes is called the "focal spot " or tube focus.
• Rotates at high speed  :- 3200 rpm or 10,000
  

Two type of anode :-

1. Stationary anode 

1. Rotating anode

1. Rotating anode :-

• The anode is a attached to a cylindrical part known as the" rotor".
• The rotor is actually part of motor that is made of rotate very high speed.
• The most x-ray tube revolution per minute is usually 3200 for standard technologist setting, however if the technologist select exposure factors that are considerably larger and therefore very hot, than the rotor can rotate at much greater speed extending 5000rpm.
• The rotation of the anode ensure that into any one spot will receive successive pulses of the electrons.
• If there was a rotation then it is very likely that he anode face would be damaged to high heat.

The anode disc :- composed of
      Disc:- molybdenum
      Target focal track*rhenium & tungsten
      Backed by graphite go improve heat
The part of the rotating anode :-

•  The tungsten disc, The tungsten have a belelloed edge by 6°-20° to utilise the line focus principle, typical size of the disc are 75 mm, 100mm,and 125mm.
• The rotating assembly with silvery as lubricant and ball bearings.ball bearing of the both edge improve the machine of the anode.
• A molybdenum stem,poor heat conductor,to minimize,the the role of conduction and increase heat lost by radiation.

Why the copper block ?

     It is improve the thermal capacity of the       anode even further allowing it to handle       higher temperature than the tungsten           plate alone.

Why the tungsten ?

• Characteristics of the tungsten alloy.
• It has high atomic number (74).
• Characteristics interaction.
• High melting point.
• Heat conduction.

Focal spot angle :-

• Focal spot characteristics, large and small focal spot superposed, anode angle facilities X-RAYs directed downward.
• The focal spot which are imbedded in the rotating anode disc are angled in such a way that when the electrons strike the focal track , the angle makes it easier for X-RAY to be emited in a downward direction.
• While the projectile electron do not "bounce " away from the target the at which is  positioned allows more X-ray to be directed toward the image receptor or film.

Stationary anode tube :-

• Low powered systems.
• Anode does not rotate.
• Poor heat loading.

Glass envelope :-

• High evacuated.
• Tolerates high heat.
• Made of pyrex.
• Window or port is thinner.
• Coating of glass 10y vaporized w.
• Immersed in oil.
• The contents of the tube are sealed by in vacuum inside a glass chamber.
• If gas is present in the enclosure, ionisation would occur producing a widely variable and unwanted tube current (which depend on the number of flowing electron) and variable x-ray energy (which depends on the speed of electrons).
• Vacuum allows the number of electrons(mA) and the speed of electron (kV) to be controlled independently.

Induction motor :-

    -  Causes rotor to rotate

Protective housing :-

• Support the tube. 
• Cools the tube.
• Insulates from high voltage.
• Controls leakage radiation.