L 2: Production and properties of radiation Flashcards
(11 cards)
1
Q
Neutron production
A
- is due to photodisintegration
- This results in change in atomic mass number but not the atomic number
- A is changed Z remains same
2
Q
Binding energy
A
- It is dependent on Z
- As Z increase the binding energy increases.
- It is due to coulombs interaction with nuclear protons.
- Electron binding energy is proportional to Z square.
3
Q
Chemical identity of the element is due to
A
Z
number of protons
4
Q
Characteristic X-ray production
A
- Otter shell electron descends to inner shell vacancy
- X-ray energy is = difference in binding energy of 2 shells.
- X-rays produced have discrete energy
5
Q
Auger electron production
A
- It can induce further damage in the organic macromolecues such as DNA
6
Q
Decay constant
A
Itis the reciprocal of the mean life and therefore has units inverse of time
7
Q
Half life of common isotopes
A
Americum-214 = 432 years
Cesium -137 = 30 years
Samarium-145 = 340 days ~ 1 year
Iridium-192 = 73.8 days
Iodine-125 = 59.4 days
Ytterbium -169 = 32 days
Palladium-103= 17 days
Gold-198 = 2.7 days
8
Q
Desired target angle
A
Diagnostic - 6-17 deg
Therapheutic - 30 Deg
9
Q
Bremsstrahlung production
A
- Proportional to EZ^2
- So dependent on incoming energy and atomic number of the material
- Emitted photons are continuos
- Max energy is equal to incident energy
- Mean energy is 1/3 of Emax
10
Q
Characteristic x-rays are
A
equal to differences in energy levels between each electron orbital shell.
11
Q
SI Unit for mass attenuation co eff
A
m2/kg
