פוטוגרפיה מצגת 6

Front 1

What two main parts make up the x-ray tube?

Back 1

Cathode and anode

קתודה ואנודה

Front 2

What two types of radiation are produced in an x-ray?

Back 2

קרינת בלימה וקרינת אופיינית

Front 3

What is the "fuse" הארה in קרינת בלימה וקרינת אופיינית?

Back 3

מתח וזרם חשמלי

Front 4

ייצור קרינת X הוא תוצר של המרת אנרגיה ____ לקרינת ____?

Back 4

קינטית, אלקטרומגנטית

Front 5

Which three conditions have to occur (in order) to make x-rays?

Back 5

1. ענן אלקטרונים חופשיים

2. מתח גבוה בין הקתודה לאנודה

3. בלימה פתאומית של אלקטרודים באנודה

1. Free electron cloud

2. High מתח tension between cathode and anode

3. Stopping the electrons suddenly in the anode

Front 6

From what material is the interior of the x-ray tube made?

Back 6

זכוכית ממנה שאבו את האוויר ליצירת ריק vacuum

Front 7

What is the purpose of the vacuum in an x-ray tube?

Back 7

To enable free electrons

Front 8

Which part of the x-ray tube has a negative charge and shoots electrons?

Back 8

Cathode

Front 9

Which part of the x-ray tube has a positive charge and serves as the target for the electrons?

Back 9

Anode

Front 10

Why are the electrons attracted to the anode?

Back 10

It has a positive charge

Front 11

??? What does the anode do to create the electromagnetic energy that makes the x-rays?

Back 11

??? The anode suddenly stops spinning and electrons are released (or energy?). בלימה???

Front 12

What are the two important components of the cathode?

Back 12

1. Metal filament סליל (usually from thungsten) that makes the electron cloud
2. Made from thungsten

Front 13

Why is tungsten used in the cathode and on the target of the anode?

Back 13

1. Atomic number 74
2. High melting point (3400°C, gold is about 2000°...)

Releases large number of photons in a short time, withstands heat

Front 14

How does the filament get electricity?

Back 14

From the electric מתח and זרם from a special power line, up to 10 volts.

Front 15

How does the filament give electrons?

Back 15

When lit up, the filament heats up and the electrons in the outer rings are freed in an electron cloud.

Front 16

What types of חוט is in the filament and why?

Back 16

Long מוקד קטן and short מוקד גדול--the length designates the size of the target area in the anode.

Front 17

What is the typical shape of the anode?

Back 17

Round (disc)

Front 18

How does the cathode release the electrons?

Back 18

The plates in the filament are negative--reject the electrons in the direction of the anode.

Front 19

What type of metal may be used in a mammogram machine and why?

Back 19

Molybdenum, bc mammogram x-rays are low voltage (about 25v instead of 40)

Front 20

Why is the שטח הפגיע at an angle?

Back 20

So the x-ray beams can be directed toward the opening of the tube.

Front 21

What is the advantage of a round anode that spins?

Back 21

Lasts longer bc the electrons hit a different spot each time.

Front 22

What is קרינת בלימה or bremsstahlung (or קרינה שבירה)?

Back 22

Electrons with high kinetic energy are released from the cathode and hit the tungsten atoms of the anode. The nuclei in the tungsten have a strong bond and cause the electrons to change direction and lose energy, in the form of x-rays.

Front 23

What % of קרינת בלימה energy is x-ray?

Back 23

1% (99% is heat)

Front 24

What are the three different ways an electron shot from the cathode can create קרינת בלימה and which are x-rays?

Back 24

1. Enter nucleus, make high-frequency wave and most energy (don't need that energy in x-rays)
2. Get close to nucleus then suddenly change direction, moderate energy (x-ray)
3. Get close to nucleus then make a wider turn, lowest energy (still x-ray)

Front 25

What is the spectrum of קרינת בלימה?

Back 25

0 - 90 kVp

Front 26

What is the highest possible energy in קרינת בלימה and why?

Back 26

90 kVp, electrons get as close as possible to nucleus without hitting it

Front 27

What are the three parameters of an x-ray?

Back 27

1. kVp - strength of electrons
2. MA - number of electrons (mass?)
3. S - seconds

Front 28

Why are x-rays heterogenic?

Back 28

The electrons are stopped in stages, so their losses of kinetic energy results in photons of different levels of energy, and rays of different wavelengths.

Front 29

Electrons with more kinetic energy result in x-rays that are more ___ ?

Back 29

penetrating

Front 30

The shortest wavelength in results in the weakest/strongest ray.

Back 30

Strongest

Front 31

The shortest wave emits photons in accordance with the ____ selected.

Back 31

מתח

Front 32

קרינת בלימה

results in relatively a lot of _____

and a little_____.

Back 32

קרינה רקה

קרינה קשה

Front 33

קרינה רקה What is ?

Back 33

Waves under 40, doesn't penetrate. Body absorbs all of it, so does damage but has not benefit.

Front 34

What is קרינה אופיינית?

Back 34

Energy created when electrons shot from the cathode hit electrons in the K ring (of the tungsten) and knock them out of place. An electron from L must fill it's place, losing energy in the move, released in the form of an x-ray. (To remove an electron from tungsten (atomic # 69.5), the electrons shot at it must be at least 70 kev)

Front 35

Characteristic radiation is called that bc it is characteristic of the _____ used.

Back 35

Material

Front 36

Most mammograms use _____ radiation.

Back 36

Characteristic

Front 37

_____ radiation appears as spikes and ____ appears as a wide wave.

Back 37

Characteristic

בלימה

Front 38

Characteristic radiation is easier/harder to make in molybdenum than in tungsten, because it has a lower electron binding energy.

Back 38

Easier

Front 39

A target area mafe of tungsten in an x-ray tube will most likely use what type of radiation?

Back 39

בלימה

Front 40

What type of imaging uses characteristic radiation and need energy of only 20 KEV?

Back 40

Mammogram

Front 41

Ma=

KV=

S=

Back 41

זרם חשמלי

מתח חשמלי

זמן

Front 42

True or false?:

Both processes of radiation (characteristic and בלימה) occur inside the x-ray tube.

Back 42

True

Front 43

מתח=

זרם=

Back 43

Strength of current

# of electrons

Front 44

True or false?: in an electric current, the electrons flow and the protons do not move.

Back 44

True

Front 45

What is the measurement of an electric current זרם and to what does it refer?

Back 45

A (amperes), refers to the number of electrons that flow

Front 46

MA=

S=

MAS=

KV=

Back 46

MA=Miliampere

S=Second

MAS=Miliampere per second (represents flow)

KV=מתח, strength, speed of electrons from cathode to anode

Front 47

The זרם that passes through the x-ray tube is measured in what units?

Back 47

MA (miliampere)

Front 48

The ____ is what decides the number of electrons hitting the target area of the anode and affects the amount of radiation.

Back 48

זרם

Front 49

The זרם of the filament ____ the filament to create electrons.

Back 49

heats

Front 50

מתח חשמלי:

Back 50

The difference in the electric potential between two points, measured in volts (V)

Front 51

Electric current in an x-ray tube is measured in ___ ?

Back 51

Kv (how fast the electrons flow toward the anode)

Front 52

The Kv chosen equals the ____ highest level of energy in the x-ray spectrum.

Back 52

highest

Front 53

The higher the מתח, the faster the free electrons will move toward the anode, the higher the ____ energy.

Back 53

kinetic

Front 54

Time in an x-ray refers to the length of exposure and is measured in ___ or ___.

Back 54

seconds, milliseconds

Front 55

More time exposure means more ___ and more ____.

Back 55

electrons, radiation

Front 56

If, for example, 400 MA for .25 seconds, produces 5000 x-rays, how many x-rays are produced if we change the time to .5 seconds?

Back 56

10,000

Front 57

200 MA × .1 S = 20 MAS. How can we raise the MAS to 40?

Back 57

400 MA × .1S

200 MA × .2S

Front 58

400 MA × .1S = 40 MAS200 MA × .2S = 40 AND

Which option is better?

Back 58

Higher MA (# of electrons) at less time, to reduce chance of movement

Front 59

Today, the radiography only chooses the ___?

Back 59

KVP

Front 60

MAS ⬇️

FOCUS AREA ❔

RESOLUTION ❔

Back 60

MAS ⬇️

FOCUS AREA ⬇️

RESOLUTION ⬆️

Front 61

What are the 5 steps that happen in the cathode?

Back 61

1. The זרם of the filament heats the wire of the filament סליל.
2. The heat frees the electrons from the filament.
3. The electrons concentrate in an electron cloud.
4. The filament house has a negative charge and keeps the electrons together in a cloud and aimed toward the anode. The number of electrons in the cloud depends on the זרם. (MA)
5. The negative charge shoots the electrons toward the anode. The speed of the electrons depends on the מתח selected KV.

Front 62

What are the 4 steps that happen in the anode?

Back 62

1. The disc starts spinning
2. The positive charge of the disc attracts the electron cloud.
3. The electrons hit the anode.
4. X-rays (1%) and heat are produced (99%).

Front 63

קרינה x הוא תוצר של:

א. המרת אנרגיית חום לאנרגיה קינטית

ב. המרת אנרגיית קינטית לקרינה אלקטרומגנטית

ג. המרת אנרגיית חשמלית לאנרגיה כימית

ד. המרת אנרגיה כימית לאנרגיה חשמלית

Back 63

ב

Front 64

היחס בין חום לקרינת רנטגן בזמן יצירת הארה בשפופרת אבחון הוא:

Back 64

99:1