Another quiz p7 111 :((((( Flashcards
Why do we use tungsten? 3 yan
- Atomic number
- Thermal conductivity
- High melting point (3410 C)
The addition of ? to ? —- to the tungsten filament enhances the
1-2% thorium
enhances the efficiency of thermionic emission and prolongs tube life
What is the focusing cup made of?
Nickel
Effectiveness of focusing cup is determined by the ?? and ??, and ??
Size and shape, and position of the filament
The focusing cup is ??? charged
negatively
Protective housing reduces the intensity of leakage radiation to less than?
1 mGy a/h
Dual filament cathode designed to provide focal spots of —- and mm
0.5 mm and 1.5mm
Measurements of filament?
mm in diameter
length
The filament is 2mm in diameter and 1-2cm long
What is the main purpose of our cathodes, 3 to
Production of electron cloud, Accelerate the electrons towards the cathode, focuses the electron stream
The cathode has two components?
Filament and focusing cup
Filament measurements
Thick
Long
diameter
0.1-0.2 mm thick
1-2 cm long
2 mm diameter
The filament is a?
small coil of thin thoriated tungsten wires
When the current through the filament is sufficiently high, the outer shell electrons of the filament atoms are “boiled off” and ejected from the filament
Thermionic emission
2 types of anode
Stationary and Rotary
Premium alloy tungsten embedded in a —- degree angle in the end of —- —-
45 degree angle, end of copper rod
what is the tungsten usually made with?
Rhenium tungsten alloy
The target of a rotating anode tube is powered by an ???
induction motor
why is molybdenum/ graphite used in the rotating tube
because it is lighter, less density making the anode lighter and easy to rotate
Area of the anode struck by the electrons from the cathode
Target
Entire rotating disk length
5-13 cm
Induction motor has 2 parts
Stator and rotor
Difference between the stator and the rotor
The stator is the part outside made out of electromagnets that equally space around the length of the tube
The rotor is the part inside it is made out of copper and soft iron
the rotor is made out of
copper and soft iron
