(thank Dave for these)

OBJECTIVES CHAPTER 1

1. State the commutative and associative laws of addition and multiplication

ANS:  Commutative  Law (order)

a + b = b +a

a x b = b x a

Associative Law (grouping)

a + b + c = (a + b) + c =  a + (b + c)

a x b x c = (a x b) x c = a x (b x c)

2. State the properties of the number “1”

ANS:  anything x  or  /  1 = itself

              anything / itself = 1

3. Calculate problems using exponents and scientific notation

4. List and define units of radiation measurement and absorbed dose

ANS:

Meter (m) – the distance measured from the pole to the equator divided into 10,000,000 equal units.

Electron Volt (ev) – the amount of energy that an electron will gain if placed inside a potential difference of one volt.

Roentgen (R) – the amount of ionization that takes place in a known volume of air. 2.58 x 10 -4 coulombs / kilogram of air.

Radiation Absorbed Dose (rad) – amount of energy absorbed per gram of matter. 100 ergs /  grams of matter.

Gray (Gy) – amount of energy absorbed per kilogram of matter. 1 joule / kilogram of matter. 1 Gy = 100 rads.

Radiation Equivalent Man (rem) – radiation protection, rad times the quality factor, takes into account different types of radiation.

Sievert (Sv) – gray times the quality factor, takes into account different types of radiation just like the rem. 1 Sv= 100 rem.

6. State the relative basic rules in geometry and trigonometry for circles, triangle, and parallel lines.

ANS: CIRCLE : 360 degrees

            C = 2 II r

            II = 3.14

            C/ diameter = 3.14

            C = II x D

            Radius = 1/2 the diameter

            A = II r^2

RIGHT TRIANGLE:  Height / Base/ Hypotenuse

   c 2 = a 2 + b 2

   A = 1/2 (ab)

ANGLES OF A RIGHT TRIANGLE: SOHCAHTOA

Sin = opposite/ hypotenuse        a/c

Cos = adjacent / hypotenuse      b/c

Tan = opposite / adjacent           a/b

- opposite angles are equal

- alternate exterior angles are =

- alternate interior angles are =

OBJECTIVES CHAPTER 2

1. State who discovered x-rays and in what year.

ANS: Roentgen 1895

2. Define fluorescence:

ANS:

Fluorescence – emission of electromagnetic radiation, especially of visible light, stimulated in a substance by the absorption of incident radiation and persisting only as long as the stimulating radiation is continued.

3. Label Parts of an x-ray tube and state their function.

ANS:

Anode – target (made of tungsten), attracts electrons. (positive charge)

Cathode – filament (made of tungsten) boils off electrons Thermionic Emission. (negative charge)

Power Supply – AC

Rectifier – converts AC to DC

Glasstube – vacuumed tube

Window

necessary circuitry that is needed to control filament current.

* pg. 15 has diagram

4. State the device used to convert AC to DC.

ANS: Rectifier

5. Define and explain bremsstrahlung radiation.

ANS:

Bremasstralung Radiation – the production of x-rays by the interaction of high -speed electrons and the nucleus of an atom.

Explanation – because of potential difference between the cathode and the anode, the electron travels from the cathode to the anode building up speed until it interacts with the nuclear field of the tungsten atoms in the target. The closer the electron is to the nucleus the stronger the interaction will be / and the more energy the electron will lose to the photon. If all of the energy is not lost to the photon then the electron continues on until all of its energy is used.

6. Define thermionic emission.

ANS:

Thermionic Emission- the boiling off of electrons. (in our case the e- are boiled off from the tungsten filament.)

7. State the three types of interactions that an electron can under go in the target and which ones will produce x-rays.

ANS:

- exitation

- ionization

- bremsstralung

* ionization & bremsstralung produce x-rays

8. State the reason for using a rotating anode in an x-ray tube.

ANS:  To create more surface area and dissapate heat

9. State the meaning KVP, KEV, and KV.

ANS:

KVP – Kilo Volt Potential. Voltage supplied across an x-ray tube

KEV – Kilo Electron Volt. Used to measure monoenergetic photon beams. The max. energy the electron has reached when it hits the target.

KV – Kilo Volt. Polyenergetic. This indicates the highest possible energy in the beam.

10. Define ionizing radition.

ANS:

Ionizing Radiation – the ability to add or remove electrons from an atom causing atom to be + or - . ( in our case we remove electrons)

11. State two types of ionizing radiation.

ANS:  Electromagnetic radiation (no mass, no charge) , and particulate radiation. Electrons, protons (mass and / or charge)

12. State the relationship between electron energy and speed.

ANS: it is directly proportional (Increased Speed Increased Energy, Decreased Speed Decreased Energy.)

13. State the properties of an electron.

ANS:

- has a charge of –1

- small mass

- energy is related to speed

- not as penetrating as photons i.e. due to its mass and charge

14. State the properties of electromagnetic radiation.

ANS:

- travels in waves

- no mass no charge

- energy is related to wavelength and frequency

- photon

15. State the speed of electromagnetic radiation.

ANS: 3 x 10 8 m/per sec in a vacuum.

16. State the relationship between energy and wavelength of a photon.

ANS: The smaller the wavelength and frequency the higher the energy

17. State the three interactions that are important in radiation therapy that photons under go with matter.

ANS:

- Compton Interaction

- Photoelectric

- Pair production

18. State what is Compton interaction.

ANS:

Compton -  photons deposit part of its energy to an outer shell electron, photon loses energy and electron gets ejected (and can possibly go on to create more reactions)

19. Define exposure and state the value of the Roentgen.

ANS:

Exposure- amount of ionization produced in air with photons. / which is also the number of electrons liberated from the air

R = 2.58 x 10 -4   coulombs / per kl of dry air

20. Label the parts of a standard free ionization chamber.

ANS:

- 2 plates

- ammeter

- battery

21. Define electronic equilibrium.

ANS:

The number of electrons gained = the number of electrons lossed

22. Name the chamber that is used on a day to day basis in a therapy department.

ANS: Thimble Chamber

23. State the limitation on the use of the Roentgen.

ANS:

- only for x-rays and gamma

- air must be dry

- electron liberated must give up all there energy before collection occurs

- need electron equilibrium