Exposures 2 test 2
The angle on an anode of a x-ray tube helps ensure that more of extra photons produce at the target are
Directed towards the patient
A modern dual focus X-ray tube contains 1 one filament 2 two filament 3 one anode
2 and 3
The anode of a modern rotating in a tube is generally composed of a combination of tungsten, and 1 copper 2 rhenium 3 molybdenum
2 and 3
Vibration of the x-ray tube during a Radiographic exposure will most likely result in 1 an increase in optical density 2 a decrease in radiographic contrast 3 an increase in the amount of focal spot blur
2 and 3
The main function of the Pyrex glass that forms a protective envelope of x-ray tube is 1 the containment of the electron stream near the filament 2 the containment of the vacuum within the x-ray tube 3 the production of the statistic, electrical field around the filament
2 only
The temperature at which thermionic emission occurs is approximately
2200 degrees C
The rotation speed of an anode in most single phase x-ray unit is about
3000 rpm
The major reason that tungsten is the material chosen for the electrodes of a modern x-ray tube. Is it high melting point of about?
3400 degrees
The steepness of the anode angle affect the amount of the 1 anode heal effect 2 field coverage 3 thermionic emission
1 and 2
Which of the following factors will affect size of the focal spot 1 angle of the anode 2 speed of the rotation 3 size of the filament
1 and 3
A reduction in the Kilovoltage, setting during the operation of an x-ray tube will most likely 1 reduce the speed of the electron stream 2 increase the filament temperature 3 decrease the space charge
1 only
Which of the following events occur within the X-ray tube during the exposure (second) stage of the timer mechanism 1 a high potential difference is developed 2 filament heating begins 3 the movement of Bucky grid begins
1 only
If the angle on a x-ray tube, anode is decreased from 12° to 7°. It will result in a decrease in. 1 state of the focal spot 2 loading capacity of the tube 3 field coverage
1, 2, and 3
The maximum anode heat storage capacity of a radiographic tube is related to the type and size of the 1 anode disk 2 thermal cushion 3 external housing
1, 2, and 3
Tungsten is the principal material used in the formation of the 1 surface of the target of a rotating anode 2 surface of the target of a stationary anode old 3 wire used in the helix of the x-ray tube filament
1, 2, and 3
42 induction motor ball bearings 43 anode stem 44 stator windings 45 anode disk 46 tube envelope 47 filament
1, 5, 2, 3, 4, 7
Radiographic examination to require a large tube, current or cereal. Exposures will often play high Speed, rotating anodes with rotational speed of about.
10,000 rpm
The target of a modern rotating, and it is believed, or inclined to an angle of between
10-12 degrees
Which of the following are not an advantage of a rotating type anode tube
A reduction in the amount of low energy photons produced during an exposure
In Order to prevent movement of electrons from the anode during the exposure cycle, the type of current employed for an X-ray tube is
Direct current
The speed and energy of the electron stream as it passes across the x-ray tube is primarily controlled by the
Applied kilovoltage
The filaments in most modern extra tubes are surrounded by metal collar switch serve to
Compress the electron stream
In stationery anode tube, the target is imbedded in an anode made of
Copper
The discovery of x-rays was made by Willhelm ranking in 1895 blocks your meeting with the partially evacuated glass tube called a/an
Crookes tube
The negative electrode of an x-ray tube is commonly called the
Filament
The main reason tungsten is employed as filament material in x-ray tube is its
High melting point
The general formula that is used to determine the ant hill units, created with a fully rectified x-ray tube is
Hu= ma x kv x time
When a radiographer changes from a small to a large focal spot for an exposure, he/she is actually
Selecting a larger filament
The reduction of effective focal spot size from about 2 mm to 1 mm can be accomplished by
Selecting the smaller of the two filaments
The principal method by which the sphere charge can be increased in a mod or tube, is by employing a higher
Mas setting
The line focus principal concerns, the fact of target, angulation and focal spot size. Which is a true statement of this principle.
More than one but not all of above
The majority of heat in a modern rotating in a tube is dissipated through the
Passage of radiant heat to the tube envelope
The ball bearing, which aid in the rotation of the induction motor, require a special vaporizing, lubricating material called
Powered silver
The amount of heat storage capacity of a rotating, and it is not dependent upon which of the following
Prep boost time
The formation of the space charge in a filament of an x-ray tube is accomplished during the of the normal exposure cycle
Prep or boost
The x-ray tube envelope is composed of a heat resistant material called
Pyrex glass
Which is the proper sequence of material transverse by the x-ray beam after leaving the anode of the x-ray tube
Pyrex glass, oil, aluminum
The material that is often added to a rotating anode disk to reduce surface defects and cracks is called
Rhenium
Which of the following portions of induction motor and anode desk assembly of a rotating anode is not normally contain within the vacuum of tube
Stator windings
The temperature of the filament in a modern x-ray tube is most closely related to
The amount of current impressed on the filament
The principal disadvantage of the use of a smaller focal spot during a radiographic exposure is
The limitation of the amount of mass that can be applied to the anode
The durability and efficiency of the tungsten filament is often improved by the addition of the metal
Thorium
The first modern Radiographic tube having a heated filament was originally developed in the early 1900s by
William Coolidge
The thin, flatten surface of the x-ray tube envelope which allows for the minimum absorption of x-rays is term the
X-ray window
The unit of power the watt is derived from the product of
amperage x voltage
In a modern x-ray tube, the positively charged electrode that serves as a target for the electron stream is the
anode disk
In a rotating anode, molybdenum stem is a poor conductor of heat this material helps in preventing
bearing damage of the induction motor
The measurement of the focal spot size and most diagnostic x-ray tubes is based on the computation of the 1 actual focal spot 2 effective focal spot 3electronic focal spot
effective focal spot
Amount of space charge, created at the cathode is primarily controlled by the
impressed amperage
As ma increases, blooming of the focal tract results in a/an
increase in the size of the effective focal spot
In a modern rotating anode, the motion of the rotating disk is accomplished by the use of an
induction motor
The collective repulsion of the electron cloud around the cathode that creates an equilibrium with the rate of electron emission by the filament is termed the
space charge effect
In a modern diagnostic x-ray tube, the majority of the heat that is produced during the x-ray production process is created and concentrated on the
surface of the focal tract
In a modern diagnostic x-ray tube, the vast majority of the energy of the electron stream, striking the target of the anode is converted into
thermal energy (heat) at the surface of the anode
The process by which heating of the filament results in the liberation of electrons in the x-ray tube is called
thermionic emission