Matter and Radiation

Question 1

What is in the nucleus of a hydrogen atom? Can a nucleon be the same size a nucleus?

Answer 1

1 proton
Yes, in hydrogen the nucleus consists of just 1 proton (nucleon) t/f nucleus and nucleon can be the same size.

Question 2

What is the formula for binding energy

Answer 2

2n^2

Question 3

What is photon fluence

Answer 3

number of photons that pass through a specified cross-section

Question 4

What is energy fluence

Answer 4

sum of energy of all photons passing through this cross-section over a time.

Question 5

What is beam intensity

Answer 5

-The energy per area per unit time

Question 6

What is the inverse square law? What assumptions does it make?

Answer 6

Intensity is proportional to 1/d^2 IF use a point source + no attenuation

Question 7

What is air kerma?

Answer 7

kinetic energy released to matter – gives an indirect measurement of energy fluence.

Question 8

What is a nuclide

Answer 8

nuclear species with a specific proton, neutron and energy state

Question 9

What is an isomer?

Answer 9

Metastable version of radionuclide. Exists for a long time before decaying Eg 99mTc

Question 10

What is an isotone?

Answer 10

Same number of neutrons, different protons, different chemical properties

Question 11

What is an isotope

Answer 11

same number of protons, different number of neutrons.

Question 12

Equation for shell numbers

Answer 12

2n^2

Question 13

What is the equation for energy of a wave? What is Plank’s constant

Answer 13

E = h f
-E = energy of wave
-F = frequency (proportional to energy)
-H = Plank’s constant (6.63 x 10^-34

Question 14

What is 1 ev in Joules?

Answer 14

1.6 x 10^-19 Joules

Question 15

What is the atomic number of lead?

Answer 15

82

Question 16

What is the atomic number of tungsten?

Answer 16

74

Question 17

What is the KeV for: Barium

Answer 17

37kev

Question 18

What is the KeV for: technetium?

Answer 18

140kev (which is why it is used in nuclear imaging)

Question 19

What is the rough KeV for common elements (eg calcium)

Answer 19

Calcium =4 (very low) - not useful for contrast.

Question 20

What is the rough speed of radiowaves?

Answer 20

3 x 10^-8/ms

Question 21

At what roughly what KeVs for soft tissue and bone will there be equal photoelectric effect and compton scatter?

Answer 21

Soft tissue: 30keV
Bone 50keV

Question 22

What is K alpha and K beta emmission?

Answer 22

K alpha: emission of characteristic radiation when electron goes from L to K shell

K beta: emission of characteristic radiation when electron goes from M to K shell.