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29 Cards in this Set
- Front
- Back
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What three things do we need to make radiation? |
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What is מתח חשמלי? |
The potential difference in electricity between two points, measured in volts |
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How does the מתח work in an x-ray tube? |
The difference in electricity between the anode an cathode, referring to the electrons shooting at the anode |
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Electricity comes from outlets in ___. X-rays use electricity in _____. |
Volts, kv |
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70kv (stomach x-ray)=___volts |
7000 (outlet is 220) |
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What is מתח ישר? |
DC. Continuous current, like from a battery |
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What is מתח חילופין? |
AC. Changes in cycles. This is the type of electricity we get from the electric company. |
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What happens when the current dips below the x value? |
No electricity |
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What is זרם? |
The flow of the current, the movement of electrons from minus to plus (cathode to anode for example) |
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How do we measure זרם? |
amperes (A) (number of electrons passing per second) |
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What do we need to do to the electricity to use for an x-ray tube? |
Change the current from AC to DC |
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How does a transformer שנאי work? |
Two צלילים with a magnet in the middle to direct the electricity in one side and out the other. Can raise or lower the current. |
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Why do we need a generator? |
To convert the current from AC to DC and raise the current, also to provide a low current for the filament |
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What sets the מתח in a generator? |
The number of cycles and the type of transformer |
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What is a שנאי עצמי? |
Lets us select incoming and outgoing מתח |
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What is a diode? |
A valve that forces electricity to flow only in one direction (- to +) |
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What are the two circuits that a שנאי needs to change? |
High volt circuit and filament circuit |
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How do transformers get from 220 v to 50 kv? |
220 > שנאי עצמאי >50 v שנאי מעלה >50kv |
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How do transformers מעלה and מוריד work? |
Can raise or lower by power of 10 |
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What does a ישור מתח ? |
Changes from AC to DC and makes sure the electricity only flows in one direction |
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What does a ישור דו דרכי do? |
Changes a negative wave to a positive, giving us 2 pulses in one cycle (double frequency), uses gratz bridge to change a negative to positive |
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What does a ישור חד דרכי do? |
Cancels out the negative half of a wave, giving us pulse, blackout, pulse, blackout...(uses one diode to keep electricity from going backwards) |
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What is תפוכה? |
Production (How many pts can I xray in an hour) |
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What does a 3 phase do? |
Provides 3 different currents, so 3× more pulses per cycle. Then a ישור דו דרכי changes the negative waves to a positive ones, giving us an almost straight line. |
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What is ripple? |
The percentage of differences from the straight line (less than 2% is our aim in fleuroscopy...3-10 in rest) |
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Why do we use a high-frequency generator for x-rays? |
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What are the disadvantages of a high-frequency generator? |
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What are the advantages of a high-frequency generator for x-rays? |
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What is the dead-man switch? |
Switch that must be continually pressed to take x-ray |
