RAD PHYSICS.
What are the different way to calculate mAs?
1. mA x s= mAs
2. mAs/s= mA
3. mAs/mA= S
Define Rectification.
Process of converting Ac (alternating current) to DC (direct current). rectification is required to ensure electrons flow from cathode to anode only.
Primary circuit is measured in_______?
Amperes (current).
What is an Electronic Timer?
1.Allows wide range of intervals to be selected and are accurate intervals as small as 1ms.
What is the MOST ACCURATE timer?
Electronic Timer.
What does the induction motor do?
The induction motor powers the rotating anode of the x-ray tube.
What is Maximum efficiency?
In rectification, refers to highest percentage of AC power that can be converted into useable DC power.
Secondary circuit is measured in ____________?
Milliamperes(mA) or Kilovolts (kv) depends on the circuit type.
How does an Electronic Timer work?
They consist of rather complex circuitry based on the time required to charge a capacitor through variable resistance.
What is Mutual Induction?
The generation of an AC in a secondary coil by supplying an AC to the primary coil.
Explain the rotation of the Induction Motor.
The rotation is determined by the stators rotating magnetic field, and the rotator current.
Why is rectification needed?
To ensure electron flow from cathode to anode only.
Primary voltage is measured in_________?
Volts.
What is AC?
Alternating current, electrons that flow alternately in opposite directions.
What is Self-Induction?
A coil passes a steady, direct current. relatively unimpeded but resists the passage of Alternating current flow because of self-induction in the coil.
What does the Step-up Transformer do?
Transforms primary/incoming voltage so that the secondary voltage is more than primary voltage.
How does an AEC (Automatic Exposure Control) work?
Measures the quantity of radiation that reaches the IR. Automatically terminates the exposure when the IR has received the required radiation intensity.
Secondary voltage is measured in__________?
Kilovolts.
What is DC?
Direct current, electrons that flow in only one direction.
Why is a back-up timer needed?
Safety feature to precent overexposure by stopping the exposure completely if the AEC fails.
What is the High Voltage Transformer's job?
1. step up transformer
2. secondary voltage is higher than primary voltage because number of secondary windings is greater than the number of primary windings.
3. Increases incoming voltage to high levels to produce x-rays.
What is the main reason for AEC?
to ensure consistent image quality and minimize patient dose.
What is Thermionic Emission?
The release of electrons from the heated filament.
What controls AC and DC?
Rectifiers. Inverter converts DC to AC
What is the origin of Gamma Rays?
Originate from the nucleus.